What do we commonly use as evidence to decide whether something is alive?

Why is visible movement alone not a sufficient criterion to define life?

According to the text, what type of movement is considered necessary for life by professional biologists?

Why is there a controversy about whether viruses are truly alive?

Which of the following correctly explains why molecular movements are necessary for life? (a) They allow organisms to grow visibly. (b) They help organisms repair and maintain their organised structures. (c) They enable organisms to reproduce rapidly. (d) They allow organisms to respond to light.

What happens to the organised structure of a living organism if molecular movements stop?

Define 'life processes' as given in the chapter.

Why do life processes need to continue even when an organism is not performing any apparent activity, such as when it is asleep?

From where do organisms obtain the energy needed for their maintenance processes?

What is the process by which a source of energy is transferred from outside the body to inside the body called?

Which of the following best describes the role of food in an organism's body according to the introduction? (a) Food only provides energy for movement. (b) Food provides energy and raw materials for growth and maintenance. (c) Food only supplies water to the cells. (d) Food is needed only during periods of activity.

Why does the body need additional raw materials from outside, apart from energy?

On what type of molecules does life on Earth depend, according to the text?

What chemical reactions are described as among the most common means to break down molecules in the body?

What is respiration, as defined in the introduction of this chapter?

Why do single-celled organisms not need specialised organs for taking in food, exchange of gases, or removal of wastes?

Why is simple diffusion insufficient to meet the requirements of all cells in a large, complex multicellular organism?

In multicellular organisms, food and oxygen are taken up at one place but all parts of the body need them. What does this situation create a need for?

What are the by-products of chemical reactions that use carbon sources and oxygen for energy generation?

What is the process of removing waste by-products from the body called?

Which of the following is NOT listed as a life process essential for maintenance in the introduction? (a) Nutrition (b) Respiration (c) Reproduction (d) Excretion

Why must the energy from outside sources be converted into a uniform source of energy inside the body?

According to the text, what is the relationship between body size/complexity and the need for specialised tissues in an organism?

In a multicellular organism, if specialised excretory tissue develops, what additional system is required and why?

Which of the following pairs correctly matches a life process with its purpose? (a) Nutrition — removal of wastes from the body (b) Respiration — breaking down food to release energy (c) Excretion — transporting oxygen to cells (d) Transportation — synthesising food from sunlight

Explain why living organisms are described as 'well-organised structures' and why this organisation tends to break down over time.

What would happen to a living organism if it could not perform maintenance/life processes?

How does the complexity of carbon sources in food influence the type of nutritional process used by an organism?

The text states that the outside sources of energy 'need to be broken down or built up in the body.' Why is this necessary?

List any four life processes mentioned in the introduction as essential for maintaining life.

Using examples from the text, explain why a dog that is asleep can still be considered alive, even though it does not show visible external movement.

What is the term used for the maintenance functions that living organisms must carry out to stay alive?

Why is visible movement alone not considered a sufficient criterion to define life?

According to the text, what kind of movement is considered necessary for life by professional biologists?

Which of the following is considered the most fundamental evidence of life according to professional biologists? (a) Visible growth of an organism (b) Molecular movement within the organism (c) The green colour of plants (d) The ability to reproduce

Why must living organisms continuously repair and maintain their structures?

Why is there a controversy among scientists about whether viruses are truly alive?

State one reason why life processes must go on even when an organism is not doing any particular activity (e.g., when it is asleep).

What is the source of energy that organisms use for their maintenance (life) processes?

What do we commonly call the process by which energy is transferred from a food source outside the organism's body to the inside?

Which of the following correctly describes why energy is needed for life processes? (a) Energy is needed only for movement and growth. (b) Energy is needed to prevent the breakdown of the organism's ordered, organised structures. (c) Energy is needed only to digest food. (d) Energy is needed only for reproduction.

On what type of molecules does life on Earth primarily depend, according to the text?

The text states that food sources used by organisms are mostly carbon-based. What reason does the text give for this?

What is the term used in the text for the process of acquiring oxygen from outside the body and using it to break down food for cellular needs?

Why do multicellular organisms need a transportation system, whereas a single-celled organism does not?

Which of the following best explains why diffusion alone is insufficient for meeting the needs of all cells in a large multicellular organism? (a) Multicellular organisms do not require oxygen. (b) Not all cells of a multicellular organism are in direct contact with the surrounding environment. (c) Multicellular organisms produce more waste than unicellular organisms. (d) Diffusion only works for gases, not for food materials.

What is meant by 'oxidising-reducing reactions' in the context of breaking down molecules for energy, as mentioned in the text?

Name any FOUR life processes mentioned in Section 5.1 that are essential for maintaining life.

What problem does specialisation of tissues in multicellular organisms create with regard to the supply of food and oxygen?

What are 'by-products' in the context of cellular energy generation, and why must they be removed from the body?

What is the process called by which harmful metabolic waste by-products are removed from the body?

In a single-celled organism, how are processes like intake of food, exchange of gases, and removal of wastes carried out?

What is the final form to which all outside energy sources must be converted inside the body, and why?

Which of the following is NOT listed as a life process in Section 5.1? (a) Nutrition (b) Respiration (c) Reproduction (d) Excretion

Explain in your own words why the outside sources of energy need to be 'broken down or built up' in the body before they can be used.

Living organisms are described in the text as 'well-organised structures'. What does this mean, and why is maintaining this organisation essential for life?

The text mentions that 'additional raw material will also be needed from outside' if the body size of an organism is to grow. What are these raw materials primarily composed of, according to the text?

How does the complexity of carbon sources in food influence the type of nutritional process an organism uses?

According to Section 5.1, why would a specialised excretory tissue in a multicellular organism also require the transportation system to function?

The text says life processes must go on 'even when we are just sitting in class, even if we are just asleep'. What does this tell us about the nature of life processes?

In Section 5.1, why does the text describe food as 'a source of energy from outside the body'?

What are bio-catalysts used by organisms to break down complex food substances called?

Which of the following correctly describes autotrophic nutrition? (a) Intake of complex food prepared by other organisms (b) Intake of simple inorganic materials and use of sunlight to synthesise organic material (c) Break-down of food outside the body and then absorption (d) Deriving nutrition from plants or animals without killing them

Name the two groups of organisms that use autotrophic nutrition.

In what form is excess carbohydrate stored in plants after photosynthesis?

What is the equivalent of starch (the stored carbohydrate in plants) in human beings?

List the three main events that occur during the process of photosynthesis as stated in the chapter.

Which cell organelle contains chlorophyll?

What is the function of guard cells in a leaf?

How does a stomatal pore open? What causes the guard cells to swell?

Why does a plant close its stomatal pores at times?

In Activity 5.2, potassium hydroxide is placed inside the bell jar with one of the plants. What is the purpose of using potassium hydroxide in this experiment?

Some desert plants take up carbon dioxide at night instead of during the day. What do they do with it during the day?

Name any TWO mineral elements (other than carbon, hydrogen, and oxygen) that plants absorb from the soil and state the importance of nitrogen among these.

In what forms do plants absorb nitrogen from the soil?

Which of the following is an example of heterotrophic nutrition? (a) A green plant making food using sunlight (b) Bread mould breaking down food outside its body and then absorbing it (c) A bacterium synthesising food from CO₂ and water (d) A plant storing starch in its leaves

Give TWO examples of organisms that break down food material outside their body and then absorb it.

What is parasitic nutrition? Give TWO examples of organisms that use it.

How does Amoeba capture and digest its food?

How does Paramoecium take in food? How is this different from Amoeba?

What is the alimentary canal?

Which of the following is the correct role of salivary amylase? (a) It digests proteins into amino acids (b) It breaks down fats into fatty acids and glycerol (c) It breaks down starch into simple sugar (d) It neutralises the acid in the stomach

What is the name of the fluid secreted by salivary glands, and what enzyme does it contain?

What are peristaltic movements and what is their role in digestion?

Name the THREE substances secreted by the gastric glands in the stomach.

What is the role of hydrochloric acid in the stomach?

Why is mucus secreted in the stomach?

What regulates the exit of food from the stomach into the small intestine?

Why is the small intestine longer in herbivores than in carnivores?

Which organ produces bile juice, and what are the TWO main functions of bile in digestion?

The action of bile salts on large fat globules is compared in the chapter to which everyday process?

Name the TWO enzymes present in pancreatic juice and state what each one digests.

The food coming from the stomach into the small intestine is acidic. How is it made alkaline, and why is this necessary?

What are the final products of digestion of (i) complex carbohydrates, (ii) proteins, and (iii) fats as mentioned in the chapter?

What are villi? Where are they found and what is their function?

Which of the following correctly describes what happens in the large intestine? (a) Complete digestion of carbohydrates and proteins takes place (b) Bile and pancreatic juices are secreted into it (c) Water is absorbed from the undigested food material (d) Villi absorb digested food into the blood

How is waste material removed from the body after the large intestine has absorbed water from it?

What is dental caries and how does it begin?

Explain why brushing teeth after eating helps prevent dental caries.

In Activity 5.1, why is the plant kept in a dark room for three days before the experiment begins?

In Activity 5.1, what colour change in the leaf indicates the presence of starch, and which reagent is responsible for this change?

What does Activity 5.1 (using variegated leaves) allow us to conclude about the relationship between chlorophyll and photosynthesis?

Why does the survival of heterotrophs depend directly or indirectly on autotrophs?

How does the digestive system of a single-celled organism differ from that of a complex multicellular organism in terms of specialisation?

Which part of the alimentary canal is responsible for the complete digestion of carbohydrates, proteins and fats?

Describe the complete process of nutrition in human beings, tracing the journey of food from the mouth to absorption in the small intestine. Include the role of each organ and the enzymes/juices involved.

What raw materials do autotrophic plants require for photosynthesis, and from where does each raw material come?

How do the range of strategies in heterotrophic nutrition differ based on how the food is obtained? Give examples of each strategy mentioned in the chapter.

Which of the following statements about the small intestine is INCORRECT? (a) It is the longest part of the alimentary canal (b) It receives secretions from both the liver and the pancreas (c) It is where hydrochloric acid is produced to digest food (d) Villi present in it increase the surface area for absorption

Gas exchange also occurs across the surface of stems and roots, not just leaves. What does this tell us about the importance of stomata being the ONLY route for gas exchange in plants?

The chapter states that 'the length of the small intestine differs in various animals depending on the food they eat.' Using this information, predict whether a cow or a lion would have a longer small intestine, and explain why.

What is photosynthesis?

Which organisms are classified as autotrophs?

Name the two inorganic raw materials that autotrophs use during photosynthesis.

In what form is energy stored in plants after photosynthesis?

What is the internal energy reserve of a plant called?

What substance serves as the internal energy reserve in human beings, analogous to starch in plants?

Name the cell organelle that contains chlorophyll.

What are stomata and where are they found?

Which cells control the opening and closing of stomatal pores?

Why does a plant close its stomata?

How does the stomatal pore open?

Which of the following is NOT a raw material for photosynthesis? (a) Carbon dioxide (b) Water (c) Oxygen (d) Sunlight

The products of photosynthesis that are not immediately used by the plant are stored as: (a) Glycogen (b) Glucose (c) Starch (d) Protein

Which of the following correctly describes what happens to the stomata when guard cells shrink? (a) The pore opens wider (b) The pore closes (c) The pore remains unchanged (d) The guard cells burst

In Activity 5.1, why is the potted plant kept in a dark room for three days before the experiment?

In Activity 5.1, what is the purpose of dipping the leaf in alcohol after boiling it in water?

What does a blue-black colour upon adding iodine solution to a leaf indicate?

In Activity 5.2, what is the role of potassium hydroxide in the experimental set-up?

List the three events that occur during the process of photosynthesis as stated in the textbook.

Explain how carbon dioxide is obtained by a plant for photosynthesis.

How do plants obtain water needed for photosynthesis? Through which part of the plant is it absorbed?

Apart from carbon dioxide and water, name any TWO other minerals that plants take up from the soil for building their body.

Why is nitrogen important for plants? In what form is nitrogen taken up by plants?

Describe the process of autotrophic nutrition, stating the raw materials required, the energy source, and the products formed.

Some desert plants take up carbon dioxide at night rather than during the day. What does this suggest about the steps of photosynthesis?

How does gaseous exchange occur in plants? Is it limited only to leaves?

In Activity 5.1 using a variegated leaf, which parts of the leaf would turn blue-black after the iodine test — the green parts or the non-green parts? Give a reason based on the chapter.

In Activity 5.2, the plant kept with potassium hydroxide (which absorbs CO2) would show less starch compared to the control plant. What conclusion can be drawn from this about photosynthesis?

Why do autotrophs need sunlight for photosynthesis? What specific step in photosynthesis requires light energy?

The carbon and energy requirements of autotrophic organisms are fulfilled by photosynthesis. How does photosynthesis serve BOTH these requirements simultaneously?

The text states that chlorophyll is essential for photosynthesis. How does Activity 5.1 (using a variegated leaf) demonstrate this? Explain the logic of the experimental design.

What type of nutrition is described in section 5.2.2?

Which of the following is an example of heterotrophic nutrition? (a) Green plants making food from CO₂ and water (b) Fungi breaking down food material outside the body and then absorbing it (c) Some bacteria using sunlight to synthesise food (d) Desert plants preparing intermediates using CO₂ at night

According to the text, on what do heterotrophic organisms depend for their survival?

Name any three examples of organisms that exhibit heterotrophic nutrition by breaking down food material outside the body before absorbing it.

Which of the following organisms breaks down food material OUTSIDE its body and then absorbs it? (a) Amoeba (b) Mushroom (c) Cuscuta (d) Tapeworm

What is the parasitic nutritive strategy, as mentioned in the text?

Give any four examples of organisms that use the parasitic nutritive strategy, as stated in the text.

Which of the following is described in the text as a parasitic organism? (a) Yeast (b) Bread mould (c) Cuscuta (amar-bel) (d) Mushroom

According to the text, what is the key feature that distinguishes a parasitic nutritive strategy from other forms of heterotrophic nutrition?

The text states that heterotrophic organisms must break down complex substances before using them. What biological agents are used to achieve this breakdown?

According to the text, what two factors influence the form of nutrition in different heterotrophic organisms?

The text compares the nutritive apparatus of a cow and a lion. What difference in food source between the two animals is used to explain why their nutritive strategies differ?

Which of the following correctly describes how some heterotrophic organisms obtain nutrition, according to the text? (a) They synthesise food using sunlight and chlorophyll (b) They take in whole food material and break it down inside their bodies (c) They convert carbon dioxide and water into carbohydrates (d) They absorb minerals directly from the soil

The text describes three broad strategies by which heterotrophic organisms obtain nutrition. Briefly describe each strategy and give one example for each, using only information from the text.

According to the text, what determines what can be taken in and broken down by a heterotrophic organism that ingests whole food material?

Is cuscuta (amar-bel) an autotroph or a heterotroph? Justify your answer based on the text.

The text mentions that heterotrophic organisms use complex substances that 'have to be broken down into simpler ones before they can be used.' Why is this breakdown necessary?

Which of the following pairs of organisms both use the same heterotrophic strategy of breaking down food OUTSIDE the body? (a) Yeast and tapeworm (b) Bread mould and mushroom (c) Leech and cuscuta (d) Tick and yeast

The text says that 'each organism is adapted to its environment.' How does this statement relate to the variety of heterotrophic nutritive strategies described in section 5.2.2?

Lice and ticks are mentioned in the text as examples of which type of nutritive strategy?

According to the text, what is the range of strategies referred to for heterotrophic organisms in obtaining and using food?

Which of the following statements about heterotrophic nutrition is INCORRECT based on the text? (a) Heterotrophic organisms utilise complex substances for nutrition (b) Heterotrophic organisms depend directly or indirectly on autotrophs (c) Fungi like bread moulds break down food outside the body before absorbing it (d) Heterotrophic organisms can prepare their own food using sunlight

In what way do some heterotrophic organisms derive nutrition from plants or animals 'without killing them', according to the text? Name two such organisms.

Using information from the text, explain why the form of nutrition differs among heterotrophic organisms.

In single-celled organisms, how is food taken in?

What temporary structures does Amoeba use to engulf food particles?

What is the name of the structure formed in Amoeba when its cell surface fuses over a food particle?

What happens to complex substances inside the food-vacuole of Amoeba?

How does Amoeba get rid of undigested material?

Which of the following correctly describes how Amoeba takes in food? (a) Through a fixed mouth opening (b) Using temporary finger-like extensions of the cell surface (c) Using cilia that sweep food into a fixed spot (d) By absorbing food directly through its nucleus

Is Paramoecium a unicellular or multicellular organism?

How does Paramoecium differ from Amoeba in the way it takes in food?

What structures cover the entire surface of Paramoecium and help move food to the intake spot?

Which of the following statements about Paramoecium is correct? (a) It has no definite shape and takes in food through any part of its surface. (b) It is a unicellular organism with a definite shape and takes in food at a specific spot. (c) It is a multicellular organism that uses a digestive tract. (d) It uses temporary extensions called pseudopodia to capture food.

According to the section, how is food taken in by single-celled organisms in general?

What relationship does the section describe between increasing complexity of an organism and how it obtains nutrition?

After simple substances are formed inside Amoeba's food-vacuole by the breakdown of complex substances, how do they reach the rest of the cell?

Compare the process of nutrition in Amoeba and Paramoecium. Highlight the similarities and differences as described in the chapter.

Why does the digestive system differ in various organisms, according to this section?

In Amoeba, where does the breakdown of complex food substances into simpler ones take place?

Which of the following correctly describes what happens after Amoeba digests its food? (a) Digested food diffuses into the cytoplasm; undigested material is thrown out. (b) Digested food is stored in the food-vacuole permanently. (c) Undigested material is passed to a specialised excretory organ. (d) Digested food is pumped out of the cell and re-absorbed.

What is the role of cilia in the nutrition of Paramoecium?

The finger-like temporary extensions used by Amoeba to capture food are called ___________.

Explain, in your own words, why the digestive system is different in various organisms. Use examples from this section to support your answer.

What is the alimentary canal?

Where does the alimentary canal extend from and to?

What is saliva, and which glands secrete it?

Which enzyme is present in saliva, and what does it act upon?

What simple product is formed when salivary amylase breaks down starch?

What is the name of the muscular movement that pushes food along the alimentary canal?

Name the food-pipe that carries food from the mouth to the stomach.

Name the three substances released by the gastric glands in the stomach.

What is the function of mucus secreted by the gastric glands?

Which muscle regulates the exit of food from the stomach into the small intestine?

Which part of the alimentary canal is described as its longest part?

Name the two organs whose secretions the small intestine receives to aid complete digestion.

What is the role of bile juice produced by the liver in the digestion of fats?

Name the two enzymes present in pancreatic juice and state what each digests.

What are villi, and where are they found?

What is the function of villi in the small intestine?

Into what simpler molecules are proteins, complex carbohydrates, and fats finally converted by the enzymes in the small intestine?

What is the main function of the large intestine in the digestive process?

How is undigested waste material finally removed from the body?

Why does the food we eat need to be crushed and wetted before it enters the alimentary canal?

Why does the stomach's acidic food need to be made alkaline when it enters the small intestine?

Why do herbivores have a longer small intestine than carnivores?

The digestion of which nutrient begins in the mouth?

Which of the following is the correct function of hydrochloric acid in the stomach?

Where does the complete digestion of carbohydrates, proteins and fats take place?

What is the enzyme pepsin, and where is it secreted?

How does bile act on fats in a manner similar to how soaps act on dirt?

What are biological catalysts, and by what name are they known?

What organ secretes bile juice, and what are its two roles in the small intestine?

Describe the journey of food from the mouth to the stomach, naming all the structures it passes through.

What happens to absorbed food after it is taken up by the villi?

Why is the small intestine fitted into a compact space despite being the longest part of the alimentary canal?

Which part of the alimentary canal regulates the exit of waste material from the body?

What does the intestinal juice secreted by glands in the walls of the small intestine do to proteins and complex carbohydrates?

Why does the stomach expand when food enters it?

What is the role of the muscular walls of the stomach during digestion?

Describe the process of digestion in the human alimentary canal, tracing the food from the mouth to the anus and explaining what happens at each stage.

Why does the lining of the alimentary canal need to be kept moist and soft?

The food coming from the stomach is acidic. How is this acidity managed in the small intestine, and why is this management necessary?

Which of the following correctly describes the function of lipase in digestion?

Which of the following lists the correct final products of the digestion of proteins, carbohydrates and fats respectively?

What does the enzyme trypsin act upon, and where is it secreted?

Why do large fat globules need to be broken into smaller ones before enzyme action can proceed efficiently?

Name the condition that occurs when excessive acid is produced in the stomach or when mucus fails to protect the stomach lining adequately.

State two uses of the absorbed digested food in the cells of the body, as mentioned in the text.

Which gland secretes pancreatic juice, and name any two enzymes it contains?

How does the structure of the small intestine make it well-suited for the absorption of digested food? Explain with reference to specific features mentioned in the text.

The muscular tongue plays an important role during eating. What is its function as described in the text?

What is dental caries, and how does it begin according to the text?

How does brushing teeth after eating help prevent dental caries?

What is the first step in the breakdown of glucose during cellular respiration, and where does it take place?

Into how many carbon atoms is glucose (a six-carbon molecule) broken down in the first step of respiration, and what is the name of the product formed?

What is anaerobic respiration?

Where does the breakdown of pyruvate using oxygen take place in the cell?

What are the end products of aerobic respiration?

Which of the following correctly describes where the first step of cellular respiration (breakdown of glucose to pyruvate) takes place? (a) Mitochondria (b) Nucleus (c) Cytoplasm (d) Chloroplast

In which organisms does the conversion of pyruvate into ethanol and carbon dioxide occur, and what is this process called?

What happens to pyruvate in muscle cells when there is a lack of oxygen?

Why do we sometimes experience cramps in our muscles during sudden, intense physical activity?

What is ATP, and what is its role in cellular respiration?

The energy released during cellular respiration is used to synthesise which molecule that fuels other cellular activities? (a) ADP (b) ATP (c) Glucose (d) Pyruvate

Compare aerobic and anaerobic respiration in terms of the amount of energy released.

How do plants exchange gases required for respiration? Name the structures involved.

During the day, why do plants not release carbon dioxide even though respiration is occurring?

Why is the rate of breathing in aquatic organisms much faster than in terrestrial organisms?

How do fish take in oxygen from water?

What is the path of air entering the human respiratory system, starting from the nostrils up to the alveoli?

What is the function of the rings of cartilage present in the throat (trachea)?

What are alveoli? What is their role in the respiratory system?

The balloon-like structures at the end of the air passages in the lungs are called: (a) Nephrons (b) Villi (c) Alveoli (d) Capillaries

Describe the mechanism by which air is drawn into the lungs during inhalation.

Why do the lungs always retain a residual volume of air even after exhaling?

What is haemoglobin, and what is its role in respiration?

In which cells of the human body is haemoglobin found?

How is carbon dioxide transported in human blood?

Why is carbon dioxide transported in dissolved form in the blood rather than by haemoglobin?

With the help of a diagram or description, explain the different pathways by which glucose is broken down in various organisms.

What is the significance of the fine, delicate nature of the surface of respiratory organs in animals, and how is this surface protected?

In Activity 5.4 described in the text, why does the lime water turn milky when you breathe out through it, but takes longer to turn milky when normal air is passed through it?

In Activity 5.5 described in the text, fruit juice is mixed with yeast. What change is observed in the lime water connected to the test tube, and what does this indicate about the products of fermentation?

Name the three different end products formed from pyruvate in the three different respiration pathways mentioned in the chapter.

Which of the following is an anaerobic process? (a) Breakdown of pyruvate to CO2 and water in mitochondria (b) Conversion of pyruvate to ethanol and CO2 in yeast (c) Absorption of oxygen by alveoli (d) Transport of oxygen by haemoglobin

Why do large, complex animals need respiratory pigments like haemoglobin for oxygen transport, rather than relying on simple diffusion?

What structural features of the alveoli make them well-suited for efficient gas exchange?

How do terrestrial organisms differ from aquatic organisms in terms of the organ used for breathing and the rate of breathing?

The breakdown of pyruvate in the presence of oxygen takes place in the: (a) Cytoplasm (b) Nucleus (c) Mitochondria (d) Ribosome

State the major gas exchange activity occurring in plants during the night, and explain why this is different from what happens during the day.

What is the role of mucus in the human respiratory tract?

Name the respiratory pigment in human beings. Where is it located, and what property makes it effective for oxygen transport?

Describe in detail the process of aerobic respiration, starting from glucose and ending with the final products, mentioning the locations in the cell where each step occurs.

How does ATP function as an 'energy currency' for the cell? Give any two examples of cellular activities it can power.

Why is it said that using visible movement as the defining characteristic of life is not enough, and how does respiration relate to this?

In Activity 5.6, students observe that fish open and close their mouth and gill-slits in a coordinated manner. What is the significance of counting how often a fish opens its mouth compared to a human breathing?

Lactic acid is a: (a) Six-carbon molecule formed from glucose (b) Three-carbon molecule formed from pyruvate under anaerobic conditions in muscles (c) Two-carbon molecule formed during fermentation in yeast (d) Product of aerobic respiration

Why do the respiratory organs of terrestrial animals have their gas-exchange surfaces located inside the body rather than on the outside?

The direction of diffusion of oxygen and carbon dioxide in plant cells depends on which two factors, according to the text?

How is smoking harmful to the respiratory system? Mention the specific structures it damages and the consequences, as described in the text.

Given that the alveolar surface, if spread out, would cover about 80 m², explain how this large surface area is significant for respiration in human beings.

Compare and contrast the three pathways of glucose breakdown in organisms (aerobic respiration, fermentation in yeast, and anaerobic respiration in muscle cells) under the headings: location in the cell, products formed, and relative energy released.

What is the fluid medium in which blood cells are suspended?

Which component of blood carries oxygen?

How big is the human heart compared to a familiar object?

Name the four chambers of the human heart.

Which chamber of the heart receives oxygen-rich blood from the lungs?

Why do ventricles have thicker muscular walls than the atria?

What is the function of valves in the heart?

What is 'double circulation' in the context of blood transport?

Name the two types of blood vessels that carry blood away from and towards the heart respectively.

Why do arteries have thick, elastic walls?

What ensures that blood in veins flows only in one direction?

What are capillaries, and how thick are their walls?

Name the blood cells that help clot the blood at points of injury.

What is lymph, and how is it different from blood plasma?

State two functions of lymph as described in the chapter.

What is the normal systolic and diastolic blood pressure in human beings?

What instrument is used to measure blood pressure?

Name the two conducting tissues that form the transport system in plants.

What does the xylem transport in plants?

What does the phloem transport in plants?

What is translocation in plants?

What is transpiration in plants?

Name the energy molecule used during translocation in the phloem.

Which of the following correctly describes the function of plasma in blood? (a) It carries oxygen to all parts of the body. (b) It transports food, carbon dioxide and nitrogenous wastes in dissolved form. (c) It helps in clotting of blood at injury sites. (d) It pumps blood to all organs.

In the human heart, de-oxygenated blood from the body first enters which chamber? (a) Left atrium (b) Left ventricle (c) Right atrium (d) Right ventricle

In fishes, how many chambers does the heart have, and how many times does blood pass through the heart in one body cycle? (a) Four chambers; twice (b) Three chambers; twice (c) Two chambers; once (d) Three chambers; once

Which of the following organisms has a three-chambered heart according to the text? (a) Mammals (b) Birds (c) Fishes (d) Amphibians

Which of the following best describes the role of transpiration in plants? (a) It only cools the plant surface. (b) It helps in the absorption and upward movement of water and minerals, and also helps in temperature regulation. (c) It transports food from leaves to roots. (d) It is responsible for the opening and closing of stomata only.

The energy for translocation in phloem is provided by: (a) Sunlight (b) ATP (c) Root pressure (d) Transpiration pull

High blood pressure (hypertension) is caused by: (a) Dilation of arterioles (b) Constriction of arterioles (c) Decrease in blood volume (d) Rupture of capillaries

Explain why the human heart needs separate chambers for oxygenated and de-oxygenated blood.

Describe the path taken by oxygenated blood from the lungs to the body and the path taken by de-oxygenated blood from the body back to the lungs, naming the chambers involved.

Differentiate between arteries and veins on the basis of (i) direction of blood flow, (ii) wall thickness, and (iii) presence of valves.

Why do plants have low energy needs for transport compared to animals? What consequence does this have for their transport systems?

How does water move from the soil into the roots and then upward through the xylem? Explain with reference to both root pressure and transpiration pull.

Explain how sucrose is loaded into and moved through the phloem tissue. What role does osmosis play in this process?

What is lymph? How is it formed and what functions does it serve in the body?

Why is double circulation necessary in birds and mammals but not in fishes? Relate your answer to the energy needs of these animals.

What is blood pressure? Distinguish between systolic pressure and diastolic pressure.

What happens when blood capillaries develop a leak? How does the body prevent excessive blood loss?

Why is the transport of materials through xylem described as being driven by 'simple physical forces', while phloem transport requires energy?

Give a detailed account of the components of the human transport system and the functions of each component.

Describe how water and minerals are transported in plants. In your answer, explain the role of (i) root pressure, (ii) transpiration, and (iii) the xylem tissue.

Compare the transport of water in xylem and food in phloem in plants. Discuss the direction of movement, the energy requirement, and the substances transported in each case.

Where does exchange of materials between blood and surrounding cells take place in the human body?

What substance is transferred into phloem tissue to initiate translocation, and from where is it transported in spring?

Through which structures does food in the phloem move, and with the help of which associated cells?

What force drives the movement of water in xylem more significantly during the day when stomata are open?

How does the separation of oxygenated and de-oxygenated blood in the heart benefit mammals and birds? How is this different in amphibians and reptiles?

Why do plants need a transportation system even though they are stationary organisms?

Which of the following correctly explains why ions are actively taken up by root cells from the soil? (a) To increase the temperature of the root cells (b) To create a concentration difference that causes water to move into the roots by osmosis (c) To directly provide energy to the xylem vessels (d) To allow transpiration to occur at the leaves

What is excretion?

Which of the following best describes excretion? (a) The process of taking in food for energy (b) The biological process of removing harmful metabolic wastes from the body (c) The transport of oxygen to body cells (d) The breakdown of glucose to release energy

Name the four organs that make up the human excretory system.

Where are the kidneys located in the human body?

The basic filtration unit in the kidney is called a: (a) Neuron (b) Nephron (c) Alveolus (d) Villus

What is the cup-shaped end of the coiled tube associated with each capillary cluster in the kidney called?

Name the nitrogenous waste products that are removed from blood in the kidneys.

Through which tube is urine carried from the kidney to the urinary bladder?

The urethra in the human excretory system is responsible for: (a) Producing urine (b) Storing urine (c) Releasing urine out of the body (d) Filtering blood

What substances are selectively re-absorbed as the filtrate flows along the nephron tubule?

How do unicellular organisms remove metabolic wastes from their bodies?

Why is it necessary for organisms to remove nitrogenous metabolic wastes from their bodies?

Describe the structure and functioning of a nephron.

What factors determine how much water is re-absorbed in the kidney tubules?

The urinary bladder is described as muscular and under nervous control. What practical significance does this have for humans?

In the artificial kidney (hemodialysis), the dialysing fluid has the same osmotic pressure as blood but is devoid of nitrogenous wastes. Why is this composition important?

How does the artificial kidney differ from a natural kidney in terms of the process involved?

The initial filtrate produced in healthy adult kidneys is about 180 L daily, yet only 1–2 L of urine is excreted. What accounts for this difference?

Which of the following is NOT part of the human excretory system? (a) Kidney (b) Ureter (c) Urinary bladder (d) Pancreas

What waste product generated during photosynthesis can itself be thought of as a waste product in plants, according to the text?

List any THREE strategies that plants use to get rid of waste materials.

In which part of the plant cell are many waste products stored?

Where are resins and gums, which serve as waste storage, especially found in plants?

Plants use completely different strategies for excretion compared to animals. Give TWO reasons, based on the text, why plants can manage with simpler excretory strategies.

How do plants get rid of excess water as a waste product?

The text draws a comparison between the removal of CO₂ in lungs and the removal of nitrogenous waste in kidneys. What is the common principle underlying both processes?

Why do complex multicellular organisms require specialised organs for excretion, while unicellular organisms do not?

In hemodialysis, the patient's blood is passed through tubes with a semi-permeable lining suspended in dialysing fluid. By which process do waste products move from the blood into the dialysing fluid? (a) Active transport (b) Osmosis (c) Diffusion (d) Transpiration

What triggers the urge to urinate in human beings?

Explain how urine is produced in the human kidney, starting from the filtration of blood to the formation of final urine.

Which two organ systems together ensure that oxygen absorbed in the lungs reaches every cell in the body?

Name the life process that supplies raw materials (food) to the body AND the life process that transports those materials to all cells.

Which molecule, produced during cellular respiration, serves as the immediate energy currency for all life processes including transportation in the phloem?

The kidneys filter nitrogenous wastes from the blood, just as the lungs remove carbon dioxide from the blood. What is the name of the basic filtration unit of the kidney that performs a role analogous to the alveoli in the lungs?

In which part of the human alimentary canal is the completely digested food absorbed into the blood for transport to all body cells?

Which life process generates the carbon dioxide that is transported by the blood and ultimately expelled through the lungs?

Oxygen released as a by-product of photosynthesis in plants is used in which other life process discussed in the chapter?

Which vascular tissue carries water absorbed from the soil by roots up to the leaves for photosynthesis, and which tissue carries the products of photosynthesis to the rest of the plant?

According to the chapter, what is the ultimate reason why all life processes — nutrition, respiration, transportation and excretion — are necessary?

Which of the following correctly pairs a life process with the waste product it primarily removes from the human body? (a) Respiration — urea; Excretion — CO₂ (b) Respiration — CO₂; Excretion — urea (c) Nutrition — CO₂; Transportation — urea (d) Respiration — water; Excretion — oxygen

Which of the following statements correctly links photosynthesis with respiration in a plant during the daytime? (a) CO₂ from respiration is used in photosynthesis, so no net CO₂ is released. (b) O₂ from respiration is used in photosynthesis, so no net O₂ is released. (c) Glucose from photosynthesis is directly transported in xylem. (d) Starch from photosynthesis is broken down in the mitochondria without any intermediate step.

Haemoglobin is to oxygen transport in humans as ________ is to water transport in plants — it provides the medium/mechanism for movement. Which of the following correctly fills the blank? (a) Phloem sieve tubes (b) Xylem vessels (c) Guard cells (d) Companion cells

According to the chapter, both the alveoli in the lungs and the villi in the small intestine share one key structural feature that makes them efficient at their respective jobs. What is that shared feature?

Which of the following sequences correctly traces the path of a glucose molecule from its synthesis in a leaf to its use as energy in a root cell? (a) Leaf → Xylem → Root cell → Mitochondria (b) Leaf → Phloem → Root cell → Mitochondria (c) Leaf → Phloem → Root cell → Chloroplast (d) Leaf → Xylem → Root cell → Cytoplasm only

State the four essential life processes identified in the chapter that together maintain the living state of an organism.

Explain how the processes of nutrition and respiration are interdependent in any living organism. Use examples from the chapter.

Describe how water absorbed by the roots of a plant is connected to the process of photosynthesis occurring in the leaves, mentioning the tissue involved in its transport.

How does the circulatory system act as a link between the digestive system and the excretory system in human beings?

Why must the products of digestion be transported by the blood rather than simply diffusing to all body cells? Refer to the chapter's explanation of why transportation systems are needed.

The chapter states that the lungs and the kidneys both use clusters of thin-walled capillaries for their primary function. Name the specific structure in each organ and state the substance removed from the blood in each case.

What is the role of ATP in connecting the process of respiration to all other life processes? How is ATP described in the chapter?

How does transpiration in plants serve both the transportation process and the nutritional process of photosynthesis?

Both unicellular organisms and complex multicellular organisms carry out nutrition, respiration and excretion. According to the chapter, what is the key difference in HOW they perform these processes?

Explain why a deficiency of haemoglobin would affect not only respiration but also the overall energy available for all other life processes.

Compare the mode of transport of water in xylem with the mode of transport of food in phloem, highlighting one key difference in the energy requirement of each process.

The chapter mentions that bile juice from the liver acts on fats during digestion. How is the action of bile salts on fat globules similar to the action described for soaps in Chapter 4, as mentioned in the text?

How does the chapter explain that oxygen released during photosynthesis can be considered a waste product? Connect this to the broader definition of excretion given in Section 5.5.

According to the chapter, why do birds and mammals need a four-chambered heart with complete separation of oxygenated and deoxygenated blood, while amphibians and many reptiles can manage with a three-chambered heart? Connect your answer to their respective energy needs.

Trace the journey of a molecule of oxygen from the atmosphere to a muscle cell in the human body, naming every major structure it passes through. Your answer should span the respiratory and circulatory systems.

In the chapter, plants and animals are both described as having strategies for excretion. Compare any TWO excretory strategies used by plants (Section 5.5) with the single primary excretory strategy used by human beings, highlighting what kind of waste each strategy deals with.

The chapter discusses how the small intestine and the kidney tubules both selectively retain useful substances while allowing wastes to pass through. Compare these two processes: what useful substances are reabsorbed in each organ and what is the waste that passes on?

Explain why a blockage of the stomata in a plant would negatively affect BOTH photosynthesis (nutrition) AND the transport of water to the leaves.

Read the following statements and identify whether each is TRUE or FALSE based on the chapter. Give a one-line reason for each. (i) Aerobic respiration produces more energy than anaerobic respiration. (ii) Phloem transports water from roots to leaves. (iii) The alveoli and villi both increase surface area to improve efficiency. (iv) Urea is a gaseous waste removed by the lungs.

Using information from the chapter, explain how the process of excretion in human beings depends on the circulatory (transportation) system.

The chapter states that 'life on earth depends on carbon-based molecules.' Using examples from nutrition, respiration and excretion, explain how carbon enters the body, is used, and then leaves the body of a heterotrophic organism like a human being.

Describe in detail how the four life processes — nutrition, respiration, transportation and excretion — are interconnected in the human body. In your answer, explain how the failure of any ONE of these processes would disrupt all the others.

Compare and contrast the transport systems in plants and human beings under the following headings: (i) Transporting structures/organs, (ii) What is transported, (iii) Source of energy for transport, (iv) Role of a pumping organ.

Using the chapter as your source, describe the complete journey of food from the time it is eaten to the time its energy is used in a body cell and its waste products are excreted. Your answer must cover at least three life processes.

The chapter compares complex multicellular organisms to unicellular ones in terms of how they carry out life processes. Using examples of at least THREE life processes, explain why multicellular organisms need specialised organs while unicellular organisms do not.

Compare the process of aerobic respiration with anaerobic respiration (fermentation and lactic acid pathway) under the following heads: (i) Location in the cell, (ii) Reactants and products, (iii) Amount of energy released, (iv) Organisms/conditions where each occurs.

Assertion (A): In human beings, the blood that returns to the heart from the lungs is directed to the left side of the heart and then pumped to the entire body. Reason (R): This arrangement, called double circulation, ensures that oxygenated and deoxygenated blood do not mix, providing an efficient oxygen supply to tissues. Which of the following is correct? (a) Both A and R are true, and R is the correct explanation of A. (b) Both A and R are true, but R is NOT the correct explanation of A. (c) A is true but R is false. (d) A is false but R is true.

Assertion (A): Plants do not need a transport system as elaborate as the circulatory system found in human beings. Reason (R): Plants have low energy needs because they do not move, and a large proportion of their body consists of dead cells. Which of the following is correct? (a) Both A and R are true, and R is the correct explanation of A. (b) Both A and R are true, but R is NOT the correct explanation of A. (c) A is true but R is false. (d) A is false but R is true.

Assertion (A): Glucose produced during photosynthesis is sometimes stored as starch in plants and as glycogen in humans. Reason (R): Both starch and glycogen serve as internal energy reserves to be used when required. Which of the following is correct? (a) Both A and R are true, and R is the correct explanation of A. (b) Both A and R are true, but R is NOT the correct explanation of A. (c) A is true but R is false. (d) A is false but R is true.

Read the following case and answer the questions that follow. Ravi is a healthy 15-year-old boy. One day during a sprint race, he feels severe cramps in his leg muscles. After the race, his doctor explains that during intense exercise, his muscle cells did not receive enough oxygen, so they switched to a different pathway for energy generation. The doctor also mentions that the oxygen he breathes is carried to his muscles by a pigment in his blood, and that the carbon dioxide produced is transported back to his lungs. (i) Name the 'different pathway' the muscle cells switched to, and name the end product responsible for the cramps. (ii) Name the pigment that carries oxygen in the blood and the cells in which it is found. (iii) How is carbon dioxide transported from the muscles back to the lungs according to the chapter? (iv) Once oxygen is restored to the muscle cells, in which part of the cell does aerobic respiration (the breakdown of pyruvate) occur?

Read the following case and answer the questions that follow. A biologist studies two plants: Plant A is a tall tree and Plant B is a single-celled green alga living in a pond. Both are autotrophs and carry out photosynthesis. (i) How does Plant B (the single-celled alga) obtain its CO₂ and water for photosynthesis without any specialised transport system? (ii) For Plant A (the tall tree), name the two specialised tissues used for transport and state what each carries. (iii) What force primarily drives water upward in the xylem of Plant A during the day when stomata are open? (iv) Both plants produce oxygen as a by-product of photosynthesis. According to the chapter, how can oxygen be considered an 'excretory product'?

Read the following case and answer the questions that follow. A patient is diagnosed with kidney failure. Doctors place the patient on haemodialysis (artificial kidney). Meanwhile, a separate blood test reveals the patient also has very low haemoglobin levels. (i) According to the chapter, what is the principle by which an artificial kidney removes nitrogenous waste from the blood? (ii) Why is there no reabsorption step in the artificial kidney, unlike in a real nephron? (iii) How would the patient's low haemoglobin level affect the process of aerobic cellular respiration in body cells? (iv) Name the nitrogenous waste primarily removed by the kidneys that the artificial kidney would also remove, and state where in the body this waste is originally produced (as implied by the chapter).

The chapter opens by stating that 'using visible movement as the defining characteristic of life is not enough.' How do the four life processes discussed in the chapter — nutrition, respiration, transportation and excretion — collectively provide a better definition of what it means to be alive than visible movement alone?

The chapter states that 'if order breaks down, the organism will no longer be alive.' Using the four life processes as your framework, explain how each process contributes to maintaining the ordered structure of a living organism, and what happens if even one of these processes fails.

Compare the structural adaptations of the alveoli in the lungs, the villi in the small intestine, and the nephrons in the kidneys. In each case, identify: (i) the structural feature that maximises efficiency, and (ii) the specific function it serves. What common design principle underlies all three structures?