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i) Xylem and phloem 

Xylem and phloem are the conducting tubes present in the plant which are responsible for the transportation of different materials required by the plant body. 

ii) Haemoglobin and chlorophyll 

Both of them are the colored pigments just present in different organisms. Haemoglobin is present in animals whereas chlorophyll is present in plants.

Correct option  (D) (i) and (iii) only

Explanation: 

In the given figure, 'P' is aorta, 'Q' is pulmonary artery and 'R' is superior vena cava. 'R' brings deoxygenated blood from body parts towards the heart and Q carries this blood towards lungs for oxygenation. Thus, both 'Q' and 'R' carry blood having low oxygen concentration. 'Q'arises from the right ventricle so the blood will move into this blood vessel only when the ventricle contracts to push the blood into it. At this time, the atrium relaxes. 'P' carries oxygenated blood from the left ventricle to body parts.

(B) (a) - (iv), (b) - (i), (c) - (ii), (d) - (iii), (e) - (v) 

The answer is (d)

\(Glucose\overset{cytoplasm}\rightarrow Pyruvate\overset{cytoplasm}\rightarrow Ethanol+Carbondioxide\)

(a) If all the green plants disappear from the earth, then all the organisms (herbivores, carnivores and omnivores) will die due to starvation as green plants are the source of food for all organisms. 

(b) When photosynthesis occurs during the day, the carbon dioxide released by plants by respiration is all used up and not released. Similarly, some of the oxygen produced during photosynthesis is used up in respiration. Since the plant is releasing carbon dioxide and taking in oxygen even during the day, it means that no photosynthesis is taking place.

The answer is (c) Oxidation of carbon to carbon dioxide.

Correct option (D) (ii) and (iv) only

Explanation: 

During photosynthesis, light energy is converted into chemical energy. The light absorbed by the chlorophyll results in photolysis of water i.e., splitting of water into hydrogen and oxygen.

Plants have starch as the storage carbohydrate which acts as an internal energy reserve.

But animals have glycogen as an internal energy reserve.

Major events of Photosynthesis are 

• Absorption of light energy by chlorophyll.
• Conversion of light energy into chemical energy.
• Splitting of water molecules into Hydrogen and Oxygen.
• Reduction of CO₂ to from carbohydrates.

Three events which occur during photosynthesis :

(i) Absorption of light energy by chlorophyll.

(ii) Conversion of light energy to chemical energy and splitting of water molecules into hydrogen and oxygen.

(iii) Reduction of carbon dioxide to carbohydrates.

Haemoglobin is the respiratory pigment present in the human beings. It helps in the transportation of respiratory gases; mainly O₂ & some amount of CO₂ also. 

Carbon monoxide (CO) has a great affinity with haemoglobin. Increase in amount of CO in body can even cause the death of organism due to suffocation (insufficient blood supply).

Functions of large intestine in man are: 

(i) It serves to store the unabsorbed food remnants temporarily. 

(ii) It concentrates the contents by absorbing water. 

(iii) The movements of colon help to void the faeces through anus.

If the bile duct is completely blocked, bile juice will not reach the small intestine and the digestion of fats will be affected.

Bile is a digestive juice secreted by the liver. Although it does not contain any digestive enzymes, it plays an important role in the digestion of fats. Fats are present in the form of large globules in intestine which makes it difficult for enzymes to act on them. Bile salts present in bile juice break down fats into smaller globules, (i.e. emulsifies fats) which increases the efficiency of enzyme action. In addition, bile juice also makes the acidic food coming from the stomach alkaline, so that pancreatic enzymes can act on them.

It prevents our lungs to get burst out. It also prevents sticking of Iung walls and provides nourishment to inner lungs during exhalation.

Alveoli are small pouches or sacs like structure. They are surrounded by blood capillaries. Thus a large amount of air is brought in contact with the air in the lungs. More than millions of alveoli are present in the lungs. The presence of millions of alveoli in the lungs provides a very large surface area for the exchange of gases. The availability of large surface area maximises the exchange of gases.

The alveoli are adapted to make a gas exchange in lungs efficiently. They give the lungs a really, big surface area, they have moist, thin walls and they have a lot of tiny blood vessels called Capillaries. Air is sucked into the lungs and alveoli. When we breathe in the alveoli expand and maximise the exchange of gases.

The urine is made up of a number of constituents. It is an aqueous solution mainly composed of water (95%). It also consists of some organic and inorganic compounds. Other constituents include small amounts of urea, creatinine and some dissolved ions such as sodium, potassium and chloride.

The chemicals (toxic waste products) from the blood enter the dialyzing fluid through the process of diffusion when blood is passed along the tubes.

The liquid part of the blood is called plasma. Platelets help in the coagulation of blood in a cut or wound.

(i) Cellulose. 

(ii) Water, glucose, salts in similar concentration to those in normal blood. 

(iii) Urea.

Difference between Aerobic and Anaerobic respiration :

During sudden physical activity, there is a lack of oxygen in our muscles cells, the pathway for the breakdown of pyruvate into lactic acid that develops cramps in the body.

When there is a kidney failure then dialysis machine is used. Dialysis cleans the blood of a person by separating the waste substance (urea) from the blood.

Two advantages :

(i) Helps in absorption and upward movement of water and minerals from roots to the leaves.

(ii) Temperature regulation

Lower surface of leaf has more stomata than upper surface. That is why maximum transpiration occurs.

• Plants give out water in the form of water vapour through the stomata on their leaves. This is known as transpiration. 
• Two cells called guard cells are present around the stomata. They control the opening and closing of stomata. 
• Water is released into the atmosphere by leaves through the process of evaporation.
• As a result, water in the epidermal layer of the leaf decreases. 
• Water is brought up to the leaves through the xylem to compensate for the lost water. 
• Transpiration helps in absorption of water and minerals and distribution to all parts of the plant.

• Nerve cells also called as neurons are special types of cells which conduct impulses from one place to another in the body. 
• Neurons are the structural and functional units of the nervous system. 
• Nerve cells, the largest cell in the human body, may measure upto a few metres in length. 
• Nerve cells have the ability to generate and conduct electrochemical impulse. 
• The cells that support the nerve cells and help in their functioning are called neuroglia. Nerve cells and neuroglial cells together form nerves.

• An immediate and involuntary response given to a stimulus from the environment is called a reflex action. 
• Sometimes we react to an incident without any thinking on our part or control over the reaction. 
• This is a response given to a certain stimulus from the surroundings. 
• In such situations, proper control and coordination is achieved even without the intervention of the brain. 
• For example, when our hand touches a hot object, the receptor in the skin detects the stimulus. 
• The sensory neuron sends the impulse to the relay neuron in the spinal cord. 
• The impulses are then sent to motor neurons which cause the muscles of the hand to contract and move away from the hot object.
• The spinal cord is the center of co-ordination for reflex actions.

• When we undertake constant exercises, there may be shortage of oxygen for the cells.
• Therefore, our muscles and other tissues perform anaerobic respiration in such condition.
• In this process, lactic acid is formed.
• Molecules of ATP produced in oxidation of food are also much less.
• Thus, there is less energy in the body and accumulation of lactic acid too. All this brings about a feeling of exhaustion.

An enzyme RUBISCO present in plant chloroplasts.

(a) Milk: Proteins (casein) are converted into amino acids. Lactose sugar is converted into glucose. Lipids are converted into fatty acids and glycerol.

(b) Potato: Carbohydrates (starch) are converted into glucose.

(c) Oil: Lipids are converted into fatty acids and glycerol.

(d) Chapati: Carbohydrates (starch) are converted into glucose.

Ingestion refers to the consumption of food, water and other substances through the mouth into the gut. Ingestion is a general term used for taking in any substance into the digestive system.

A physical process by which oxygen is taken in and carbon dioxide is given out is called breathing.

Diffusion is the principle of exchange of gases.

For photosynthesis to occur, both sunlight and CO₂ are required. The plant forms glucose (later on converted to starch) through photosynthesis. The part Q of leaf was covered and not exposed to light and part R was kept in absence of CO₂. Thus, both parts of leaf did not form starch and gave a negative test for starch. (Note - iodine solution gives a positive test for starch and turns blue-black in colour)

Carnivores have shorter small intestine, as compared to herbivores. Carnivores consume only flesh of other animals whereas herbivores consume plant products, which contain cellulose and fibre. Meat is relatively easier to digest and provide more energy. Cellulose and other plant products take longer to be digested. Hence, carnivores possess shorter small intestine.

Plants perform photosynthesis for utilising CO₂.

i. After complete oxidation of a glucose molecules, 38 number of ATP molecules are formed.

ii. At the end of glycolysis, pyruvate molecules are obtained.

iii. Genetic recombination occurs in pachytene phase of prophase of meiosis-I.

iv. All chromosomes are arranged parallel to equutorial plane of cell in metaphase phase of mitosis.

v. For formation of plasma membrane, …………… molecules are necessary.

vi. Our muscle cells perform anaerobic type of respiration during exercise.

During aerobic respiration, the product is CO₂ & H₂O. While during anaerobic respiration, the product can be either lactic acid or ethanol+CO₂ on the basis of enzyme involved. 

If the product is ethanol &CO₂, the process is termed as Fermentation. 

Initially glucose gets converted into pyruvic acid (by the process of glycolysis-common in both aerobic & anaerobic respiration). In fermentation, this pyruvic acid produces ethanol & carbon-dioxide in the presence of enzyme alcohol dehydrogenase. This fermentation process is also used for industrial production of alcohol.

Chlorophyll.

Plants and animals have a completely different mode of nutrition. Plants are autotrophic organisms that are capable of making their own food by performing photosynthesis using 2 raw materials (water + CO₂). 

They need light energy to make their own food. Plants do not depend on any organism to obtain nutrition. On the other hand, animals are heterotrophic organisms that depend on other organisms (plants and other animals) to fulfill their nutrition requirements. They cannot make their own food.

All heterotrophs depend on autotrophs for their nutrition.

The three main types of heterotrophic nutrition are:

1. Holozoic nutrition: Complex food is taken into a specialist digestive system and broken down into small pieces to be absorbed. Eg: Ameoba, Humans

2. Saprophytic nutrition: Organisms feed on dead organic remains of other organisms. Eg: Fungi like bread moulds yeast and mushrooms.

3. Parasitic nutrition: Organisms obtain food from other living organisms (the host), with the host receiving no benefit from the parasite. Eg: cascuta, ticks, lice, leeches and tape worms.

The respiratory pigment in a human being is haemoglobin. Haemoglobin is present in RBC's of blood in humans.

Running is a heavy energy requiring process. Thus while running a 100m race, there will be a great need of energy to muscles. Thus they will start performing respiration at much higher rate. Due to this reason, there will be increased release of CO₂ by muscles.

Larynx (voice box) is present at the opening of trachea. Then the air goes into trachea-passage for air to lungs. Near the entry of trachea into lungs, it gets divided into bronchi (sing. bronchus) which further gets divided into bronchioles.

1.a. Pholem

2.a. Sucrose prepared by leaves

3.b. Water

4.b. Tracheids and vessels

5.d. Both tracheids and vessels

(i) Transpiration is the process of movement of water in the xylem tissues and its evaporation through the aerial structures of the plant like leaves and stem. It causes a transpirational pull which help in the movement of water from the roots to the leaves. 

(ii)(a) When humidity is decreased, transpiration is increased 

(b) By increasing the temperature of the surroundings, we tend to increase the rate of evaporation of water droplets through the leaves by the process of transpiration. On increasing temperature, rate of transpiration also increases. 

(iii) Amit is very interested in science subject. He believes in applying practical knowledges into real life experience.

We need a proper transportation system in almost all the organisms whether be it plant or animals. Roots take up water which is required by the whole plant body. In the same way food is produced by the leaves which is to be distributed to the whole plant, therefore, a proper transportation system is needed to fulfill all the requirements of the plant.