English Medium कक्षा १० - CBSE Important Questions

List any two differences between pollination and fertilization.

Answer the following question.
List two agents of pollination?

Trace the path a male gamete takes to fertilise a female gamete after being released from the penis.

State the number of sets of chromosomes present in a zygote.

Sexual maturation of reproductive tissues and organs are necessary link for reproduction. Elucidate.

Explain the post fertilization changes that occur in the ovary of a flower.

Given below is a diagram of a germinating seed. Label the parts that:

1. gives rise to future shoot.
2. gives rise to future root system.
3. stores food. 

State the post-fertilisation changes that lead to fruit formation in plants.

Two pea plants - one with round yellow seeds (RRYY) and another with wrinkled green (rryy) seeds produce F1 progeny that have round, yellow (RrYy) seeds.

When F1 plants are self-pollinated, which new combination of characters is expected in F2 progeny? How many seeds with these new combinations of characters will be produced when a total 160 seeds are produced in F2 generation? Explain with reason.

Sahil performed an experiment to study the inheritance pattern of genes. He crossed tall pea plants (TT) with short pea plants (tt) and obtained all tall plants in F1 generation.

What will be set of genes present in the F1 generation?

Sahil performed an experiment to study the inheritance pattern of genes. He crossed tall pea plants (TT) with short pea plants (tt) and obtained all tall plants in F1 generation.

Give a reason why only tall plants are observed in F1 progeny.

Sahil performed an experiment to study the inheritance pattern of genes. He crossed tall pea plants (TT) with short pea plants (tt) and obtained all tall plants in F1 generation.

When F1 plants were self-pollinated, a total of 800 plants were produced. How many of these would be tall, medium height or short plants? Give the genotype of F2 generation.

Sahil performed an experiment to study the inheritance pattern of genes. He crossed tall pea plants (TT) with short pea plants (tt) and obtained all tall plants in F1 generation.

When F1 plants were cross-pollinated with plants having tt genes, a total of 800 plants were produced. How many of these would be tall, medium height or short plants? Give the genotype of F2 generation.

What does sign of power (+ve or –ve) indicate?

How unit of power related to focal length of a lens?

The shiny outer surface of a hollow sphere of aluminium of radius 50 cm is to be used as a mirror: 

 What will be the focal length of this mirror?

The shiny outer surface of a hollow sphere of aluminium of radius 50 cm is to be used as a mirror: 

 Which type of spherical mirror will it provide? 

Define the following terms in the context of spherical mirrors :
(i) Pole

(ii) Centre of curvature

(iii) Radius of curvature

(iv) Principal axis

An optical device has been given to a student and he determines its focal length by focusing the image of the sun on a screen placed 24 cm from the device on the same side as the sun. Select the correct statement about the device. 
(A) Convex mirror of focal length 12 cm
(B) Convex lens of focal length 24 cm
(C) Concave mirror of focal length 24 cm
(D) Convex lens of focal length 12 cm

AB and CD, two spherical mirrors, from parts of a hollow spherical ball with its centre at O as shown in the diagram. If arc AB = `1/2` arc CD, what is the ratio of their focal lengths? State which of the two mirrors will always form virtual image of an object placed in front of it and why.