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1. Different systems work in co-ordination with each other in the body of the living organisms. In human body the homoeostasis is very advanced. 

2. Digestive system, respiratory system, circulatory system, excretory system, nervous system and all the external and internal organs in the bodywork independently but in coordination with each other.

3. The digested and absorbed nutrients of the food are transported to various cells with the help of circulatory system due to pumping of the heart. Simultaneously, the oxygen absorbed in the blood by lungs is also transported to each cell by RBCs.

4. Mitochondria in every cell brings about oxidation of nutrients and produce energy required for all of these functions.

5. The control is exercised by the nervous system on all these actions. This keeps the organism alive and helps in growth and development of the same.

Both animals and plants have the ability to move. Plants are rooted and move slowly as they grow. Their roots move down into the soil and their stems move up towards the light. Animals on the other hand move quickly and can move their entire bodies. They can move in search of food, shelter or to avoid danger.

Biology is the study of living things. All living things are called organisms, both plants and animals are living organisms. But how we decide whether something is living or non-living depends on 7 life processes. If something is living it will carry out the 7 life processes below.

Thymus:

Testis:

Ovary:

1. Parathyroid

2. Pancreas

• Root cells are in contact with water and minerals in the soil. 
• Water and minerals enter the cells of the root surface due to difference in concentration. As a result, these cells become turgid. 
• This is called root pressure. 
• Under the effect of this pressure, water and minerals reach the xylem of the roots and to reduce this difference in concentration, they are continuously pushed forward. 
• As a result of this continuous movement, a water column is formed, which is continuously pushed ahead. 
• This pressure, is sufficient to lift the water up in shrubs, small plants and small trees.

Because plants have a large proportion of dead cells in many tissues, they have low energy needs. So they use a slow transport system.

Urine from nephron is brought to the collecting duct of kidneys where the urine enters the ureters. There are 2 ureters, each opening from one kidney into the urinary bladder. The urinary bladder stores urine and it size increases as the amount of urine collected increases. When the CNS gives a voluntary message the muscles of bladder contract and the bladder sphincter relaxes thus excreting urine out through the urethra.

False 

The chemical process involved in the removal of harmful metabolic wastes from the body is called ultrafiltration which occurs in the nephron of the kidney. The metabolic waste are then removed from by excretion/ defecation.

Movement of molecules does take place among cells. The cell membranes are selectively permeable and allow the movement of molecules among cell. When the movement of molecule across the cell does not require energy, it is called passive transport. Movement of molecules require energy is called active transport.

(i) Oxyhaemoglobin
(ii) Carboxyhaemoglobin and as carbonic acid (CO₂ dissolved in blood plasma).

(a) There are three types of blood vessels – arteries, veins and capillaries.

(b) Heart needs  valves to prevent the backflow of blood so that the blood flows only in one direction.

Osmoregulation is the maintenance of optimum concentration of water and salts in the body fluids.

(i) Oxalic acid 

(ii) citric acid 

(iii) Tartaric acid.

Animals, which live in dry conditions have to conserve water in their bodies. Therefore, they synthesise crystals of uric acid from their ammonia.

High pressure causes the liquid part of blood to filter out from the glomerulus into the renal tubule.

(i) The three carbon molecule formed due to break-down of glucose during respiration is pyruvate.

(ii) Urea

These features which particularly make our lungs efficient for gas exchange. 

1.Thin: the air sac walls are very thin so that gases can quickly diffuse through them. Oxygen is absorbed in to the blood and carbon dioxide is given out in to the lungs to be exhaled out. 

2.Moist: the air sacs are moist with mucus so that gases can dissolve before diffusing. 

3.Large surface area: the surface area for gases to diffuse through in human lungs is roughly the same as a tennis court. The alveoli help to increase the surface area for absorption of oxygen. 

4.Good blood supply: the air sacs or the alveoli have a large capillary network so that large volumes of gases can be exchanged. More the flow of blood more exchange. 

Respiratory unit of lungs - Alveoli

Excretory unit of kidneys - Nephrons

(i) It has a large surface area and branched. 

(ii) Contain an extensive network of blood vessels.

(iii) It is thin, delicate and fine.

Chlorophyll is green pigment present in the leaves of a plant.

Amoeba depends on simple diffusion of gases for breathing .

(a) Chlorophyll. (b) Green.

Earthworm absorbs oxygen through its moist skin.

Water controls the opening and closing of stomata. The deficiency of water causes stomata to open very little or it may even remain closed. Therefore, CO₂ (required as a raw material for photosynthesis) cannot enter into the leaves and thus lack of water slows down the rate of photosynthesis

(a) Lungs.

(b) Alveoli.

(c) Alveoli.

(d) Anaerobic, aerobic.

(e) Fish.

(a)  Autotrophs.

(b)  Heterotrophs.

(c)  Autotrophs, heterotrophs.

(d)  Carbon dioxide, water.

(e)  Starch.

(a) Autotrophs. 

(b) Heterotrophs. 

(c) Autotrophs, heterotrophs. 

(d) Carbon dioxide, water. 

(e) Starch.

Large intestine.

Small intestine.

Transpiration is the process when plants loose water as vapour.

1. a. Stomata

2. a. Guard Cells

3. b. Photosynthesis

4. d. All the options

5. b. On the underside of the leaf

Water is absorbed by the root of the plant but has to be transported to different parts of the plant like leaves and stem. It is done through xylem tissues. The flow of water and minerals in xylem is unidirectional that is from roots to leaves. The process of movement of water in the plants through xylem and its evaporation through leaves or stem is known as transpiration. It is done through stomata during the daytime. It is important as it creates a pull which is known as transpirational pull because of which the water moves from the roots to the leaves.

Diffusion parts like roots, stems, and leaves get oxygen required for respiration.

The food for plants is prepared by the green leaves by the process of photosynthesis. In this process the plant uses carbon dioxide and produce sugars in the presence of sunlight. Every part of plant body like the roots and stem also require food for its functioning so the food prepared by the leaves must be transported to different parts of the plant. The process of transportation of carbohydrates (sugar) produced by the leaves to other parts of the plant is known as translocation. It is done through Phloem tissues. The movement of carbohydrates in phloem is bidirectional.

The process of glomerular filtration, also called ultra-filtration occurs in the renal corpuscle (glomerulus + Bowman’s capsule) through numerous tiny filtration slits present in the basement membrane of renal corpuscle. This filtration is so fine that every component of plasma, except proteins (as they are large in size) pass into the Bowman’s capsule. Therefore, the filtrate from the kidneys of a mammal contains glucose and salts, but not proteins.

The Kidneys filter the blood and concentrate the filtrate to make urine. They also help regulate blood pressure. 

Ureters transport the urine to the urinary bladder. 

Urinary bladder is like a holding tank for the urine until it’s ready to be excreted. Urethra is the tube that connects the urinary bladder to the outside of the body for excretion.