Class 10 Science - Chapter Heredity and Evolution NCERT Solutions | A study found that children with light-c

Outline a project which aims to find the dominant coat colour in dogs.

How is the sex of the child determined in human beings?

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 or why not?

How do Mendel’s experiments show that traits are inherited independently?

If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?

Explain how sexual reproduction gives rise to more viable variations than asexual reproduction. How does this affect the evolution of those organisms that reproduce sexually?

Explain the terms analogous and homologous organs with examples.

How do Mendel’s experiments show that traits may be dominant or recessive?

Will geographical isolation be a major factor in the speciation of an organism that reproduces asexually? Why or why not?

How does the creation of variations in a species promote survival?

Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.

What is a good source of energy?

Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?

What are trophic levels? Give an example of a food chain and state the different trophic levels in it.

What changes can you make in your habits to become more environment-friendly?

What is the difference between a reflex action and walking?

What is the importance of DNA copying in reproduction?

Why should a magnesium ribbon be cleared before burning in air?

Define the principal focus of a concave mirror.

You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?

What does an electric circuit mean?

Explain the following terms with one example each.

(a) Corrosion
(b) Rancidity

Why is respiration considered an exothermic reaction? Explain.

Why do acids not show acidic behaviour in the absence of water?

In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte?

Give an example of a double displacement reaction other than the one given in activity 1.10.

What are the problems caused by the non-biodegradable wastes that we generate?

Identify the substances that are oxidised and the substance that are reduced in the following reactions.

    (i)    4Na(s)   +   O₂(g)    →    2Na₂O(s)
    (ii)   CuO(s)   +   H₂(g)    →    Cu(s)   +   H₂O(l)

Explain the following in terms of gain or loss of oxygen with two examples each.

(a) Oxidation
(b) Reduction

A concave lens of focal length 15 cm forms an image 10 cm from the lens. How far is the object placed from the lens? Draw the ray diagram.