Question

Which of the following statements are correct?
(i) Stamens are male reproductive part whereas carpels are the female reproductive part.
(ii) In Spirogyra, asexual reproduction takes place by fragmentation.
(iii) Vegetative propagation by leaves occurs in sweet potato.

A. (i) and (ii)
B. (ii) and (iii)
C. (i) and (iii)
D. All of the above

Answer 1

Hint: Sexual reproduction is the mode of reproduction when two parents of opposite sex participate in the reproduction. It involves the fusion of male and female gametes to form a single celled zygote. Asexual reproduction is the mode of reproduction where a single parent is capable of producing offspring. Asexual reproduction is common mode of reproduction in unicellular organisms and in plants and animals having simple body organisation. Different organisms adapt different methods by which they reproduce asexually. These methods may include simple cell division, fragmentation, fission or vegetative propagation etc. Whereas organisms reproducing sexually follows common events that include pre-fertilisation, fertilisation and post-fertilisation events. The male and female gamete fuse together to form a zygote and then further development occurs and ultimately an organism is formed.

Complete Step by Step Answer:
Flowers are the reproductive organ of a plant. Flowers bear both male reproductive parts called stamen and female reproductive parts called carpels either on the same plant or on a different individual plant. Thus statement (i) is correct.

Fragmentation is a mode of asexual reproduction where if a body breaks into different fragments, each fragment grows into an adult capable of producing an offspring.
For example, Spirogyra and Hydra.
Thus statement (ii) is correct.

In plants, the term vegetative is used for asexual. Vegetative propagation in plants occurs through different structures of a plant. These structures are called vegetative propagules. These propagules include runner, offset, rhizome, sucker, tuber, bulb, leaves etc.
Vegetative propagation by leaves occurs in Bryophyllum. Vegetative propagation in sweet potato occurs through roots.
Thus statement (iii) is incorrect.

Hence option A: (i) and (ii) is correct.

Note:Exact copies of parent are formed in asexual reproduction. The term clone is used to describe them, whereas in sexual reproduction different offspring are formed due to variation. Variation also increases their chances of survival as the organism will be able to adapt themselves in the changing environment. Unicellular organisms reproduce asexually but as the complexity of body design increases organisms shift towards sexual mode of reproduction.