10. LIFE’S INTERNAL SECRETS

I. Three plants A, B and C are placed in a beaker containing coloured water. The water in each beaker is covered with a layer of oil. The leaves were removed from plant B, while plant C was exposed to strong light.

i) In which plant A, B or C would the water move up faster ? ii) In which plant would water move slowly ? iii) Why is the water covered with oil ? iv) What is being investigated by this experiment ?

2. a) The diagram represents a certain physiological process in plants : i) Name the process. ii) What is the purpose of this experiment ? iii) Why is the pot covered with polythene bag ? iv) What precautions are taken to ensure proper results in the experiment ? v) What is the structure labeled ‘X’ ? vi) What change would you observe in ‘X’ after a while ? Explain. vii) Suggest a suitable control experiment for the comparison. b) An experiment is set−up is shown below. The leafy shoot was cut under water and then fixed to the glass tube with the rubber Tubing. Both long tubes were filled with water and then inverted into a trough containing mercury. i) What is observed after a few hours ? ii) Name the process taking place in A that accounts for the change observed. iii) Name the process taking place in B that accounts for the change observed. iv) What is the aim of this experiment ? v) What would you observe if the leafy shoot was replaced by a leafless shoot ? Explain. 3. a) Given below is a schematic diagram to illustrate some aspects of photosynthesis. i) Fill up the gaps in blank spaces (1 − 4) by writing the names of the correct items. ii) What phenomenon do the thick arrows A and B indicate ? b) Explain : All life would come to an end if there were no green plants. c) A healthy potted geranium plant with variegated leaves was watered and left in sunlight for

several hours. A leaf was plucked and tested for starch. It was found that a part of the leaf had starch, but the other had no starch. i) What is the experiment designed to show ? ii) How would you account for the presence of starch in some parts of plant, but absence in other parts ? iii) What experimental details have been omitted while performing the experiment ?

d) A candidate in order to study the importance of certain factors in photosynthesis, took a potted plants and kept it in the dark for over 24 hours. Then in the early hours of the morning she

covered one of the leaves with black paper. She placed the potted plant in the sunlight for a few hours, and then tested the leaf which was in the sunlight for a few hours covered with black paper

for starch. i) What aspect of photosynthesis was being investigated ? ii) is there any control in this experiment ? if so, state the same. iii) Why was the plant kept in the dark before the experiment ? iv) Describe step by step how the candidate proceed to test the leaf for the presence of starch. e) The healthy plants (green) were placed in the dark for 24 hours. They were then set up as shown in the figure and left for 4 hours. Then a leaf was taken from each plant and the chlorophyll was removed from the leaves. i) How is the chlorophyll removed ? ii) What is the next final step in the experiment ? iii) What would be the result of final step ? iv) Which of the two plants would serve as the control ? f) The diagram below represents a diagrammatic section through part of a leaf. i) Label the parts indicated by letters A to F. ii) State the role of C. iii) Name the gases that are likely to diffuse in the direction of the arrows : a) During the day. b) At night time. iv) What is the function of the labeled part D ?

4. The diagram given alongside represents a kidney cut open longitudinally. Study the same and

then answer the questions that follow :

i) Name the structural and functional unit of the kidney.

ii) What is the region labeled ‘1’ called ? What part of the above

mentioned structure is found in this region ?

iii) Name the part labeled ‘4’. What is its function ?

iv) Name two nitrogenous substances that are excreted by the

kidney.

5. The figure alongside is that of a nephron,

i) Label the parts 1 to 8

ii) What is the liquid entering part ‘4’ called ?

Name two substances present in it that are

reabsorbed in ‘6’.

iii) Name two substances present in the part

labelled ‘1’ which are not present in the part

labelled ‘8’.

6. The figure below shows a diagrammatic representation of the movement of certain substances inside the stem of a certain plant.

i) Which cells are located towards the centre ? ii) Which cells are located towards periphery ? iii) What does upward arrow indicate ? iv) What does down ward arrow indicate ? v) What is the result of Root pressure and transpirational pull ?

7. The diagram below represents a root hair and associated root tissue in cross-section i) Label the parts numbered 1 to 7. ii) Describe briefly the process by which soil water

enters the root hair. iii) What role is played by: a) the cell membrane b) the cell sap in the uptake of water into the root hair ? iv) What would happen to the root hair of a potted

plant if the soil was watered with a very concentrated solution of sodium chloride ?

9. The diagram below represents an apparatus which is used to demonstrate the process by which

air goes in and out of the lungs in a mammal. i) What in the diagram do the following represent ? 1. Balloons 2. Bell jar 3. Rubber sheet ii) If the rubber sheet is pulled down, what would happen to the balloons ? iii) What process in mammal is represented in above ? iv) Account for the observation in (ii). v) State three differences between this mechanism

(as represented by the figure above) and the corresponding mechanism in a mammal.)

10. Observe the given diagram and answer the following questions:

i) Name the process explained in the given diagram. ii) What type of air is present in the bronchiole ? iii) What is a nature of the blood present in the

pulmonary artery ? iv) What is the nature of the blood present in

pulmonary vein ? v) Name the corresponding structure found in

plants.

11. THE REGULATORS OF LIFE

1. Name the following : a) The hormones produced by pancreas. b) The hormone produced by adrenal gland. c) The part of brain responsible for memory. d) The endocrine gland present in Brain. e) Parts of Central nervous system. f) A male hormone. g) Three parts of Nervous system.

h) Movement in plants related to growth. i) A hormone which influences basal metabolic rate. j) The movement of plant in response to certain chemicals. k) The plant hormone promoting the growth. i) The gland referred to as the Master gland. m) Name the sense organs and respective receptors . n) The disease which occurs in adults due to the deficiency of iodine in the diet ? 2. Answer the following : a) What is the function of receptor and effector in the body ? b) How does our body respond when adrenaline is secreted into the blood ? c) What happens at the synapse between two neurons ? d) What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs ?

12. THE LIFE CYCLE

1. Describe the measures used to control the population. 2. How removal of unwanted pregnancy is misused by some people and how it has become dangerous

to the society ? 3. Write the full form of AIDS, STD, WHO . 4. What is tube pregnancy ? Why is it dangerous ? 5 Is regeneration process the same as reproduction ? Why ? 6 What is meant by placenta ? Where it is present ? What is its role ?

13. MAPPING OUR GENES 1. Justify the statement : ‘The sex of the child depends upon its father’. 2. The gene for red hair is recessive to the gene for black hair. What will be the hair colour of the person

if he inherits a gene for red hair from his mother and gene for black hair than his father ? 3. Study the problems on crosses involving a single trait and complete the given squares and answer the

questions. In a certain species of animals, black fur (B) is dominant fur (b). over brown Predict the genotypes and

phenotypes of the offspring. When both parents are Bb or have heterozygous black fur.

Genotypes ……% homozygous black fur (BB) ……% heterozygous black fur (Bb) ……% homozygous brown fur (bb) Phenotypes ……% black fur ……% brown fur 4. With proper example explains that variation caused may be helpful in the survival of species or a

change in genetic material. 5. A man with blood group A marries a woman with blood group O and their daughter has blood group

O. Is this information enough to tell you which of the traits – blood group A or O – is dominant ? Why ? 6. Why are human beings who look so different from each other in terms of size, colour and looks said to belong to the same species ? 7. In human beings, blue eye colour is recessive to brown eye colour. If a brown-eyed man has a blue eyed mother, then find : i) What are the possible genotypes of his father ? ii) What is the genotypes of the man and his mother ?

b

B

B B