English Medium कक्षा १० - CBSE Important Questions

Describe an activity to demonstrate phototropism.

Differentiate between self-pollination and cross-pollination.

Give reason for the following:

Fertilization cannot take place in flowers if pollination does not occur.

Name the reproductive and non-reproductive parts of bread mould (Rhizopus).

Name the reproductive parts of an angiosperm. Where are these parts located? Explain the structure of its male reproductive part.

How did Mendel interpret his results to show that traits may be dominant or recessive? Describe briefly.

How did Mendel explain that it is possible that a trait is inherited but not expressed in an organism?

Using height (tallness/dwarfness) of a plant as an example, show that genes control the characteristics or traits in an organism.

If we pure-bred tall (dominant) pea plant with pure-bred dwarf (recessive) pea plant we will get pea plants of F₁ generation. If we now self-cross the pea plant of F₁ generation, then we obtain pea plants of F₂ generation.

(a) What do the plants of F₂ generation look like?

(b) State the ratio of tall plants to dwarf plants in F₂ generation.

(c) State the type of plants not found in F₁ generation but appeared in F₂ generation, mentioning the reason for the same.

Why are the traits acquired during the life time of an individual not inherited? Explain.

In a cross between red coloured and white coloured flowers, when plants with red coloured flowers of F₁ generation were self pollinated, plants of F₂ generation were obtained in which 75% of plants were with red flowers and 2.5% plants were with white flowers.

Explain the inheritance of traits in the above cross with the help of a flow chart only along with the ratio of plants obtained.

Give reason for the following:

During reproduction inheritance of different proteins will lead to altered body designs.

Explain the following term related to spherical lenses:- aperture

Explain the following term related to spherical lenses: focal length

The laws of reflection hold true for ______.

An object of height 10 cm is placed 25 cm away from the optical centre of a converging lens of focal length 15 cm. Calculate the image distance and height of the image formed.

Describe an activity to show that colours of white light splitted by a glass prism can be recombined to get white light by another identical glass prism. Also draw ray diagram to show the recombination of the spectrum of white light.

State the cause of dispersion of white light passing through a glass prism. How did Newton show that white light of sun contains seven colours using two identical glass prisms. Draw a ray diagram to show the path of light when two identical glass prisms are arranged together in inverted position with respect to each other and a narrow beam of white light is allowed to fall obliquely on one of the focus of the first prism.

When we place a glass prism in the path of a narrow beam of white light a spectrum is obtained. What happens when a second identical prism is placed in an inverted position with respect to the first prism? Draw a labelled ray diagram to illustrate it.