Give biological reasons for the following:

Wooden frames of doors get jammed during the monsoon season.

Give biological reasons for the following:

Throat infections can lead to ear infections.

53.

Give biological reasons for the following:

The hand automatically shows the direction to turn a cycle without thinking.

a. The figure given below shows the epidermal cells of an onion bulb. This cell was then transferred to a drop of a sugar solution.



i. Draw a well labelled diagram of the epidermal cell as it would appear after immersion in a strong sugar solution.

ii. what is the scientific term is used for the changes as shown in (i) above?

iii. What should be done to restore the cell back to its original condition?

iv. Give the scientific term for the recovery of the cell as a result of the step taken in (iii) above

v. Define the term osmosis.

The figure given below represents an experiment to demonstrate a particular aspect
of photosynthesis. The alphabet 'A' represents a certain condition inside the flask


i. What is the aim of the experiment?

ii. Identify the special condition inside the flask.

iii Name an alternative chemical which can be used instead of KOH

iv In what manner do the leaves 1 and 2 differ at the end of the starch test? 

(a) Given below is a diagram of the lateral section of the testis of a man. Study the same and answer the questions which follow:

(i)Label the parts numbered 1 to 4 in the diagram.

(ii) State the functions of the parts labelled 1 and 3.

(iii) What is the significance of the testes being located in the scrotal sac outside the abdomen?

(iv) What is the role played by the inguinal canal?

(v) What is semen?

Draw a diagram of the human eye as seen in a vertical section and label the parts

which suit the following descriptions relating to the

i. Photosensitive layer of the eye.

ii Structure which is responsible for holding the eye lens in its position.

iii Structure which maintains the shape of the eye ball and the area of no vision.

iv Anterior chamber seen in front of the eye lens.

v Outer most transparent layer seen in front of the eye ball.

Given below is a schematic diagram showing Mendel's experiment on sweet pea plants having axial flowers with round seeds (AARR) and terminal flowers with wrinkled seeds ( aarr). Study the same and answer the questions which follow:



(i) Give the phenoeype of F1 progeny.
(ii) Give the phenotypes of F2 progeny produced upon by the self-pollination of F1
progeny.
(iii)Give the phenotypic ratio of F2 progeny.
(iv)Name and explain the law induced by Mendel on the basis of the above

The diagram given below represents the human heart in one phase of its functional activities. Study the same and answer the questions which follow:

(i) Name the phase.
(ii) Label the parts 1, 2 and 3.
(iii) Which part of the heart is contracting in this phase? Give a reason to support your answer. 
(iv)Draw a well-labeled diagram of part 1 and 2 to show the structural differences between them.