Exchange of genetic material takes place in
vegetative reproduction
asexual reproduction
sexual reproduction
budding
Two pink coloured flowers on crossing resulted in 1 red, 2 pink and 1 white flower progeny. The nature of the cross will be
double fertilisation
self pollination
cross fertilisation
no fertilisation
A cross between a tall plant (TT) and short pea plant (tt) resulted in progeny that were all tall plants because
tallness is the dominant trait
shortness is the dominant trait
tallness is the recessive trait
height of pea plant is not governed by gene T or t
Which of the following statement is incorrect?
For every hormone there is a gene.
For every protein there is a gene.
For production of every enzyme there is a gene.
For every molecule of fat there is a gene
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
round and yellow
round and green
wrinkled and green
wrinkled and yellow
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
(i) and (ii)
(ii) only
(iii) and (iv)
(ii) and (iv)
The maleness of a child is determined by
the X chromosome in the zygote
the Y chromosome in zygote
the cytoplasm of germ cell which determines the sex
sex is determined by chance
A zygote which has an X-chromosome inherited from the father will develop into a
boy
girl
X-chromosome does not determine the sex of a child
either boy or girl
Select the incorrect statement
Frequency of certain genes in a population change over several generations resulting in evolution
Reduction in weight of the organism due to starvation is genetically controlled
Low weight parents can have heavy weight progeny
Traits which are not inherited over generations do not cause evolution
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
(i) and (ii)
(i) and (iii)
(ii), (iii) and (iv)
(i), (ii) and (iii)
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 new combinations of characters. Choose the new combination from the following
round, yellow
round, green
wrinkled, yellow
wrinkled, green
A basket of vegetables contains carrot, potato, radish and tomato. Which of them represent the correct homologous structures?
Carrot and potato
Carrot and tomato
Radish and carrot
Radish and potato
Select the correct statement
Tendril of a pea plant and phylloclade of Opuntia are homologous
Tendril of a pea plant and phylloclade of Opuntia are analogous
Wings of birds and limbs of lizards are analogous
Wings of birds and wings of bat are homologous
If the fossil of an organism is found in the deeper layers of earth, then we can predict that
the extinction of organism has occurred recently
the extinction of organism has occurred thousands of years ago
the fossil position in the layers of earth is not related to its time of extinction
time of extinction cannot be determined
Which of the following statements is not true with respect to variation?
All variations in a species have equal chance of survival
Change in genetic composition results in variation
Selection of variants by environmental factors forms the basis of evolutionary processes
Variation is minimum in asexual reproduction
A trait in an organism is influenced by
paternal DNA only
maternal DNA only
both maternal and paternal DNA
neither by paternal nor by maternal DNA
Select the group which shares maximum number of common characters
two individuals of a species
two species of a genus
two genera of a family
two genera of two families
According to the evolutionary theory, formation of a new species is generally due to
sudden creation by nature
accumulation of variations over several generations
clones formed during asexual reproduction
movement of individuals from one habitat to another
From the list given below, select the character which can be acquired but not inherited
colour of eye
colour of skin
size of body
nature of hair
The two versions of a trait (character) which are brought in by the male and female gametes are situated on
copies of the same chromosome
two different chromosomes
sex chromosomes
any chromosome
Select the statements that describe characteristics of genes
(i) genes are 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
(i) and (ii)
(i) and (iii)
(i) and (iv)
(ii) and (iv)
In peas, a pure tall plant (TT) is crossed with a short plant (tt). The ratio of pure tall plants to short plants in F2 is
1 : 3
3 : 1
1 : 1
2 : 1
The number of pair(s) of sex chromosomes in the zygote of humans is
one
two
three
four
The theory of evolution of species by natural selection was given by
Mendel
Darwin
Morgan
Lamarck
Some dinosaurs had feathers although they could not fly but birds have feathers that help them to fly. In the context of evolution this means that
reptiles have evolved from birds
there is no evolutionary connection between reptiles and birds
feathers are homologous structures in both the organisms
birds have evolved from reptiles