Please refer to VBQs for Class 10 Science Heredity And Evolution. All value based questions for English Class 10 have been provided with solutions. We have provided below important values questions and answers. Students should learn these solved VBQs for Class 10 Science as these will help them to gain more marks and help improve understanding of important topics.
Heredity And Evolution VBQs Class 10 Science with Answers
Multiple Choice Questions
Question. ___ is the observable set of characteristics of an organism
(d) All of the above
Question. Which of the following statement is incorrect?
(a) For every hormone there is a gene.
(b) For every protein there is a gene.
(c) For production of every enzyme there is a gene.
(d) For every molecule of fat there is a gene
Question. A zygote which has an X-chromosome inherited from the father will develop into a
(c) X- chromosome does not determine the sex of a child
(d) either boy or girl
Question. If a round, green seeded pea plant (RR yy) is crossed with wrinkled, yellow seeded pea plant (rr YY), the seeds produced in F1 generation are
(a) round and yellow
(b) round and green
(c) wrinkled and green
(d) wrinkled and yellow
Question. A Mendialian experiment consisted of breeding of tall pea plants bearing violet flowers with short pea plants bearing white flowers. The progeny all bore violet flowers but almost half of it were short. This suggests that the genetic makeup of tall parent can be depicted as:
Question. If a normal cell of human body contains 46 pairs of chromosomes then the numbers of chromosomes in a sex cell of a human being is most likely to be:
Question. Which of the following determines the sex of a child?
(a) The length of the mother’s pregnancy
(b) The length of time between ovulation and copulation
(c) The presence of an X chromosome in an ovum
(d) The presence of a Y chromosome in a sperm
Question. Independent inheritance of two separate traits, shape and colour of seeds in Mendel’s cross on pea plants resulted in a observable ratio of:
(a) 3 : 1
(b) 9 : 3 : 3 : 1
(c) 1 : 1
(d) 9 : 4 : 2 : 1
Question. Which section of DNA provides information for one protein?
Question. The maleness of a child is determined by ___.
(a) X chromosome in zygote
(b) Y chromosome in zygote
(c) The cytoplasm of germ cells which determines the sex
(d) Sex is determined by chance
Case Study questions
Read the passage and answer the given five questions
Read the following and answer any four questions from (i) to (v) .Pea plants can have smooth seeds or wrinkled seeds. One of the phenotypes is completely dominant over the other. A farmer decides to pollinate one flower of a plant with smooth seeds using pollen from plant with wrinkled seeds. The resulting pea pod has all smooth seeds.
Question. Which of the following conclusions can be drawn?
(i) The allele for smooth seeds is dominated over that of wrinkled seeds.
(ii) The plant with smooth seeds is heterozygous.
(iii) The plant with wrinkled seeds is homozygous.
(a) 1 only
(b) 1 and 2 only
(c) 1 and 3 only
(d) 1, 2 and 3
Question. Which of the following crosses will give smooth and wrinkled seeds in same proportion?
(a) RR X rr
(b) Rr X rr
(C) RRX Rr
(d) rr X rr
Question. On crossing of two heterozygous smooth seeded plants (Rr), a total of 1000 plants were obtained in F1 generation. What will be the respective number of smooth and wrinkled seeds obtained in F1 generation
(a) 750, 250
(b) 500, 500
(C) 800, 200
(d) 950, 50
Question. The characters which appear in the first filial generation are called
(a) recessive characters
(b) dominant characters
(c) lethal character
(d) non-mendelian characters.
Question. Which of the following crosses will give 100% smooth seeds ?
(a) RR X rr
(b) Rr X rr
(c) RrX Rr
(d) rr X rr
Very short answer type questions
Question. Differentiate between dominant and recessive traits.
Answer. The character which gets expressed in the presence of its contrasting form is termed as dominant trait. The trait which remains unexpressed in the presence of its contrasting form is called recessive trait.
Question. Who is known as father of genetics?
Answer. Gregor Johann Mendel .
Short Answer Type Questions
Question. How do Mendel’s experiments show that traits may be dominant or recessive?
Answer. Mendel conducted a Monohybrid cross(crossed pure tall pea plants with pure dwarf pea plants) he observed only tall pea plants in the F1 generation, but on self crossing of the F1 progeny, both tall and dwarf pea plants were observed in F2 generation in the ratio 3: 1. Appearance of tall character in F1 and F2 generations shows tallness to be a dominant character. But absence of dwarf character in F1 and its reappearance in F2 confirms that dwarfness is recessive character.
Question. What are monohybrid and dihybrid cross? Give one example of each.
Answer. Monohybrid cross- This is the simplest cross in which only one character’s inheritance is investigated. A cross is created by crossing two plants with one contrasting characteristic, such as tall or dwarf. Dihybrid cross- A dihybrid cross is a cross between two plants with two sets of opposing characters. Round and green seed, for example, crossed with yellow and wrinkled seed.
Question. Define the following terms.
a. Heredity , b. Gene , c. Alleles
Answer. The differences in the traits shown by the individuals of a species and also by the off springs (siblings) of the same parents are referred to as variation. New variation may arise during the process of DNA copying that already has variations accumulated from previous generations. Species having suitable variations have more chance of survival if there is change in environmental conditions.
Question. What is DNA copying? State its importance.
Answer. DNA copying is the process of producing two identical replicas from one original DNA molecule during cell division. DNA is necessary to make all the RNA and proteins needed for cells to carry out necessary reactions and cellular processes in order to survive.
Question. How is the equal genetic contribution of male and female parents ensured in the progeny? Explain
Answer. During sexual reproduction, a female gamete or egg cell fuses with a male gamete or sperm cell which are haploid to form zygote. Zygote is diploid which contains 23 chromosomes from mother and 23 from father. In this way, an equal genetic contribution of male and female parents is ensured in the progeny.
Long Answer Type Questions
Question. A blue colour flower plant denoted by BB is cross bred with that of white colour flower plant denoted by bb.
(a) State the colour of flower you would expect in their F1 generation plants.
(b) What must be the percentage of white flower plants in F2 generation if flowers of F1 plants are self-pollinated?
(c) State the expected ratio of the genotypes BB and Bb in the F2 progeny.
Question. If we cross 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 F2 generation but appeared in F2 generation, mentioning the reason for the same.
(d) State Mendel’s laws of inheritance.
Answer. a) All plants of F1 generation will be tall plants.
(c) Dwarf trait is recessive trait which was not expressed in the F1 generation,
the recessive trait gets expressed in the F2 generation after self pollination.
d. Laws of Mendel
• Law of Dominance says that a gene has two contrasting alleles and one always expresses itself in the organism.
• Law of Segregation says that traits get segregated completely during the formation of gametes without any mixing of alleles.
• Law of Independent Assortment says that the traits can segregate independently of different characters during gamete formation
Question. A green stemmed rose plant denoted by GG and a brown stemmed rose
plant denoted by gg are allowed to undergo a cross with each other.
(a) List your observations regarding:
(i) Colour of stem in their F1 progeny
(ii) Percentage of brown stemmed plants in F2 progeny if F1 plants are self pollinated.
(iii) Ratio of GG and Gg in the F2 progeny.
(b) Based on the finding of this cross, what conclusion can be drawn?
Answer. (a) (i) Colour of the stem in F1 progeny: All green
(ii) Percentage of brown stem: 25 %
((iii) GG: Gg is 1: 2
(b) Based on the above cross, it can be concluded that green colour is dominant and get expressed in F1 generation. The brown stem, which does not get express itself in the F1 generation, is the recessive character.