Class 10 – Heredity and Evolution – Previous Years Questions

Previous Years Questions Notes Important Questions

Heredity and Evolution – Previous Years Questions

1. In an experiment with pea plants, a sure tall plant (TT) is crossed with a pure short plant (tt). The ratio of pure tall plant to pure tall plant to pure short palnt in F₂ generation will be
   a. 1 : 3
   b. 3 : 1
   c. 1 : 1
   d. 2 : 1 [CBSE 2023] [1 Marks]
2. What is heredity? [CBSE 2014] [1 Marks]
3. If you are asked to select a group of two vegetables, out of the following, having homologous structures which one would you select?
   1. Carrot and radish
   2. Potato and sweet potato
   3. Potato and tomato
   4. Lady finger and potato [CBSE 2016] [1 Mark]
4. In F₁ generation what does F₁ stand for? [CBSE 2017] [1 Mark]
5. Arrange the diagrams sequentially to observe the structure of a diocotyledonous seed.
   1. A, C, B
   2. B, C, A
   3. C, B, A
   4. A, B, C [CBSE 2017] [1 Mark]
6. A Mendelian experiment consisted of breeding pea plants beating violet flowers with pea plants bearing white flowers. What will be the result in F₁ progeny ? [CBSE 2018] [1 Mark]
7. Define the following:
   1. Speciation
   2. Natural selection
   3. Genetic drift [CBSE 2020] [3 Marks]
8. Explain the following:
   1. Speciation
   2. Natural selection [CBSE 2019] [3 Marks]
9. Mendel, in one of his experiments with pea plants, crossed a variety of pea plant having round seeds with one having wrinkled seeds. State Mendel’s observations giving reasons of F₁ and F₂ progeny of this cross. Also list any two contrasting characters, other than round seeds of pea plants that Mendel used in his experiments. [CBSE 2019] [3 Marks]
10. .
    1. Why is the F1 progeny always of tall plants when a tall pea plant is crossed with a short pea plant?
    2. How is F2 progeny obtained by self pollination of F1 progeny different from F1 progeny? Give reason for this observation.
    3. State a conclusion that can be drawn on the basis of this observation. [CBSE 2020] [3 Marks]
11. “Two areas of study namely ‘evolution’ and ‘classification’ are interlinked”. Justify this statement. [CBSE 2016] [3 Marks]
12. .
    1. Identify the organism shown in the figure below.
    2. Name one incipient feature selected by nature.
    3. Mention any other primitive feature in birds. [CBSE 2017] [3 Marks]
13. With the help of an example justify the following statement:
    “A trait may be inherited, but may not be expressed”. [CBSE 2016] [3 Marks]
14. “A trait may be inherited, but may not be expressed.” Justify this statement with the help of a suitable example. [CBSE 2014] [3 Marks]
15. All human chromosomes are not paired. Most human chromosomes have a maternal and a paternal copy, we have 22 such pairs. But one pair called sex chromosomes, is odd in not always being a perfect pair. Women have a perfect pair of sex chromosomes. But men have a mismatched pair in which one is normal sized while the other is a short one.
    1. In humans, how many chromosomes are present in a zygote and in each gamete ?
    2. A few reptiles rely entirely on enviroment cues fir sex determination. Comment.
    3. “The sex of a child is a matter of chance and none of the parents are considered to be responsible for it.” Justify it through flow chart only.
    4. Why do all the gamete formed in human females have an X chromosomes ? [CBSE 2023] [5 Marks]

1. Define evolution. How does it occur? Describe how fossils provide us evidences in support of evolution. [CBSE 2016] [5 Marks]
2. Genotype of Rhode Island red variety of poultry bird is denoted as RR and that of White Leghorn as rr. When these two are crossed,
   1. What variety of bird would you expect in their F1 progeny?
   2. Give the percentage of White Leghorn, if F₁ birds are doing natural insemination.
   3. In what ratio would you find the genotypes RR and Rr in F₂ progeny? [CBSE 2017] [5 Marks]