In human females, an event that reflects onset of reproductive phase is
(a) growth of body
(b) changes in hair pattern
(c) change in voice
(d) menstruation
During adolescence, several changes occur in the human body.
Mark one change associated with sexual maturation in boys
(a) loss of milk teeth
(b) increase in height
(c) cracking of voice
(d) weight gain
Reproduction is essential for living organisms in order to
(a) keep the individual organism alive
(b) fulfill their energy requirement
(c) maintain growth
(d) continue the species generation after generation
Offspring formed as a result of sexual reproduction exhibit more variations because
(a) sexual reproduction is a lengthy process
(b) genetic material comes from two parents of the same species
(c) genetic material comes from two parents of different species
(d) genetic material comes from many parents
In Figure, the parts A, B and C are sequentially
(a) cotyledon, plumule and radicle
(b) plumule, radicle and cotyledon
(c) plumule, cotyledon and radicle
(d) radicle, cotyledon and plumule
Which among the following statements are true for sexual reproduction in flowering plants?
(i) It requires two types of gametes
(ii) Fertilisation is a compulsory event
(iii) It always results in formation of zygote
(iv) Offspring formed are clones
(a) (i) and (iv) (b) (i), (ii) and (iv)
(c) (i), (ii) and (iii) (d) (i), (ii) and (iv)
Which of the following statements are true for flowers?
(i) Flowers are always bisexual
(ii) They are the sexual reproductive organs
(iii) They are produced in all groups of plants
(iv) After fertilisation they give rise to fruits
(a) (i) and (iv) (b) (ii) and (iii)
(c) (i) and (iii) (d) (ii) and (iv)
Length of pollen tube depends on the distance between
(a) pollen grain and upper surface of stigma
(b) pollen grain on upper surface of stigma and ovule
(c) pollen grain in anther and upper surface of stigma
(d) upper surface of stigma and lower part of style
Factors responsible for the rapid spread of bread mould on slices of bread are
(i) large number of spores
(ii) availability of moisture and nutrients in bread
(iii) presence of tubular branched hyphae
(iv) formation of round shaped sporangia
(a) (i) and (iii) (b) (ii) and iv)
(c) (i) and (ii) (d) (iii) and (iv)
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