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Select the statements that describe characteristics of genes (i) genes are a specific sequence of bases in a DNA molecule (ii) a gene does not code for proteins (iii) in individuals of a given species, a specific gene is located on a particular chromosome (iv) each chromosome has only one gene (a) (i) and (ii) (b) (i) and (iii) (c) (i) and (iv) (d) (ii) and (iv)

b) (i) and (iii) Explanation Genes control the functions of DNA and RNA. Proteins are the most important materials in the human body which not... View Article

The two versions of a trait (character) which are brought in by the male and female gametes are situated on (a) copies of the same chromosome (b) two different chromosomes (c) sex chromosomes (d) any chromosome

a) Copies of the same chromosome Copies of same chromosome from the male and female gametes pair up to form a chromosomal pair or gene which... View Article

From the list given below, select the character which can be acquired but not inherited (a) colour of eye (b) colour of skin (c) size of body (d) nature of hair

c) Size of the body The size of the body is an acquired trait because it can be changed on the availability of less or more food. The other... View Article

According to the evolutionary theory, the formation of a new species is generally due to (a) sudden creation by nature (b) accumulation of variations over several generations (c) clones formed during asexual reproduction (d) movement of individuals from one habitat to another

b) Accumulation of variations over several generations Darwin’s evolutionary theory of natural selection gave a more rational explanation of... View Article

Select the group which shares the maximum number of common characters (a) two individuals of a species (b) two species of a genus (c) two genera of a family (d) two genera of two families

a) Two individuals of a species Species is the lowest taxon hence members of the same species share a maximum number of common... View Article

A trait in an organism is influenced by (a) paternal DNA only (b) maternal DNA only (c) both maternal and paternal DNA (d) neither by paternal nor by maternal DNA

c) Both maternal and paternal DNA A trait of an organism is influenced by both maternal and paternal DNA. It is passed down from one generation... View Article

Which of the following statements is not true with respect to variation? (a) All variations in a species have an equal chance of survival (b) Change in genetic composition results in variation (c) Selection of variants by environmental factors forms the basis of evolutionary processes. (d) Variation is minimum in asexual reproduction

a) All variations in a species have an equal chance of survival. All variations in a species do not have equal chances of survival. Some... View Article

If the fossil of an organism is found in the deeper layers of earth, then we can predict that (a) the extinction of organism has occurred recently (b) the extinction of organism has occurred thousands of years ago (c) the fossil position in the layers of earth is not related to its time of extinction (d) time of extinction cannot be determined

b) The extinction of organisms has occurred a thousand years ago Fossils provide direct evidence of evolution. Fossils are body remains of dead... View Article

Select the correct statement (a) Tendril of a pea plant and phylloclade of Opuntia are homologous (b) Tendril of a pea plant and phylloclade of Opuntia are analogous (c) Wings of birds and limbs of lizards are analogous (d) Wings of birds and wings of bat are homologous

(a) Tendril of a pea plant and phylloclade of Opuntia are homologous Tendril of a pea plant and phylloclade of Opuntia are homologous because... View Article

A basket of vegetables contains carrot, potato, radish and tomato. Which of them represent the correct homologous structures? (a) Carrot and potato (b) Carrot and tomato (c) Radish and carrot (d) Radish and potato

c) Radish and carrot Homologous structures are those that are related to common ancestry. Such structures have a common structural plan and are... View Article

Two pea plants one with round green seeds (RRyy) and another with wrinkled yellow (rrYY) seeds produce F1 progeny that have round, yellow (RrYy) seeds. When F1 plants are selfed, the F2 progeny will have a new combination of characters. Choose the new combination from the following (i) Round, yellow (ii) Round, green (iii) Wrinkled, yellow (iv) Wrinkled, green (a) (i) and (ii) (b) (i) and (iv) (c) (ii) and (iii) (d) (i) and (iii)

(b) (i) and (iv) The new combination in F2 progeny will be round, yellow and wrinkled green. The phenotypic ratio 9:3:3:1 is obtained. Parents:... View Article

New species may be formed if (i) DNA undergoes significant changes in germ cells (ii) chromosome number changes in the gamete (iii) there is no change in the genetic material (iv) mating does not take place (a) (i) and (ii) (b) (i) and (iii) (c) (ii), (iii) and (iv) (d) (i), (ii) and (iii)

(a) (i) and (ii) Evolution will not take place without change and variation the genetic material. Hence, change in genetic material and... View Article

Select the incorrect statement (a) Frequency of certain genes in a population change over several generations resulting in evolution (b) Reduction in weight of the organism due to starvation is genetically controlled (c) Low weight parents can have heavyweight progeny (d) Traits which are not inherited over generations do not cause evolution

(b) Reduction in weight of the organism due to starvation is genetically controlled The factors affecting change in genetic frequency are... View Article

A zygote which has an X-chromosome inherited from the father will develop into a (a) boy (b) girl (c) X- chromosome does not determine the sex of a child (d) either boy or girl

b) Girl Sex determination seen in humans is XY sex determination. Ovum carries X chromosome, whereas sperm can carry either X or Y chromosome.... View Article

The maleness of a child is determined by (a) the X chromosome in the zygote (b) the Y chromosome in zygote (c) the cytoplasm of germ cell which determines the sex (d) sex is determined by chance

b) The Y chromosome in zygote A male has sex chromosomes X and Y, while a female has XX as sex chromosomes . During fertilization, the mother... View Article

In human males, all the chromosomes are paired perfectly except one. This/these unpaired chromosome is/are (i) large chromosome (ii) small chromosome (iii) Y-chromosome (iv) X-chromosome (a) (i) and (ii) (b) (iii) only (c) (iii) and (iv) (d) (ii) and (iv)

c) (iii) and (iv) Y-chromosome and X-chromosome In human males, one pair called as the sex chromosomes are unpaired. Here, one is a normal... View Article

If a round, green seeded pea plant (RR yy) is crossed with wrinkled, yellow seeded pea plant, (rr YY) the seeds produced in the F1 generation are (a) round and yellow (b) round and green (c) wrinkled and green (d) wrinkled and yellow

If a round, green seeded pea plant (RRyy) is crossed with wrinkled, yellow seeded pea plant, (rrYY) the seeds produced in F1 generation are round... View Article

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 the production of every enzyme, there is a gene. (d) For every molecule of fat, there is a gene

d) For every molecule of fat there is a gene Hormone and enzymes are made up of proteins and the formation of any particular protein Is also... View Article

A cross between a tall plant (TT) and short pea plant (tt) resulted in progeny that were all tall plants because (a) tallness is the dominant trait (b) shortness is the dominant trait (c) tallness is the recessive trait (d) height of pea plant is not governed by gene ‘T’ or ‘t’

a)Tallness is the dominant trait. A cross between a tall plant (TT) and short pea plant (tt) resulted in progeny that were all tall plants... View Article

Two pink coloured flowers on crossing resulted in 1 red, 2 pink and 1 white flower progeny. The nature of the cross will be (a) double fertilisation (b) self-pollination (c) cross-fertilisation (d) no fertilization

b) Self pollination In incomplete dominance, the cross between plants with pure red and white flowers results in F1 generation plants with all... View Article

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