English Medium कक्षा १० - CBSE Important Questions

What is observed when silver chloride is exposed to sunlight? Give the type of reaction involved.

Hard water required for an experiment is not available in a school laboratory. However, following salts are available in the laboratory. Select the salts which may be dissolved in water to make it hard for the experiment.

(A) 1, 2 and 4

(B) 1, 3 and 6

(C) 3, 5 and 6

(D) 2, 4 and 5

A metal 'M' on reacting with dilute acid liberates a gas 'G'. The same metal also liberates gas 'G' when reacts with a base.

1. Write the name of gas 'G'.
2. How will you test the presence of this gas?
3. Write chemical equations for the reactions of the metal with (1) an acid and (2) a base.

Assertion (A): Reaction of Quicklime with water is an exothermic reaction. 

Reason (R): Quicklime reacts vigorously with water releasing a large amount of heat.

Name the salt formed when sulphuric acid is added to sodium hydroxide and write its pH.

Mention the functions of Uterus in the human female reproductive system.

A student was asked to observe and identify the various parts of an embryo of a red kidney bean seed. He identified the parts and listed them as under:

I. Tegmen

II. Testa

III. Cotyledon

IV. Radicle

V. Plumule

The correctly identified parts among these are

(A) I, II and III

(B) II, III and IV

(C) III, IV and V

(D) I, III, IV and V

In the following diagram showing the structure of embryo of a dicot seed, what are the parts marked I, II and III sequentially?

A student has to perform the experiment "To identify the different parts of an embryo of a dicot seed." Select from the following an appropriate group of seeds:

(a) Pea, gram, wheat

(b) Red kidney bean, maize, gram

(c) Maize, wheat, red kidney bean

(d) Red kidney bean, pea, gram

Name and differentiate between the two modes of pollination in flowering plants.

A student identified the various parts of an embryo of a gram seed and listed them as given below :

(I) Testa

(II) Plumule

(III) Radicle

(IV) Cotyledon

(V) Tegmen

Out of these the actual parts of the embryo are :

(A) I, II, III

(B) II, III, IV

(C) III, IV, V

(D) II, IV, V

You are asked by your teacher to study the different parts of an embryo of a gram seed. Given below are the steps to be followed for the experiment:

I. Soak the gram seeds in plain water and keep them overnight.

II. Cut open a soaked seed and observe its different parts.

III. Take some dry gram seeds in a petri dish.

IV. Drain the excess water.

V. Cover the soaked seeds with a wet cotton cloth and leave them for a day.

The correct sequence of these steps is :

(A) III, I, V, IV, II

(B) III, I, II, IV, V

(C) III, IV, V, I, II

(D) III, I, IV, V, II

(a) Identify A, B and C in the given diagram and write their functions.

(b) Mention the role of gamete and zygote in sexually reproducing organisms.

In the figure, the parts marked A, B and C are sequentially:

(A) Plumule, Radicle and Cotyledon

(B) Radicle, Plumule and Cotyledon

(C) Plumule, Cotyledon and Radicle

(D) Radicle, Cotyledon and Plumule

List any two differences between pollination and fertilization.

Answer the following question.
How does suitable pollination lead to fertilization?

A student is observing the temporary mount of a leaf peel under a microscope. Draw a labelled diagram of the structure of stomata as seen under the microscope

Give reason.

Placenta is extremely essential for foetal development.

Give reason:

Uterine lining becomes thick and spongy after fertilisation.

In flowering plants, the pollen grains are transferred to stigma by pollination but the female germ cells are present in the ovary.
Explain with the help of a labelled diagram (only concerned parts), how the male germ cell reaches the ovary.