i) Development of fruit without fertilization and that are seedless is known as:
a) Polyembryony
b) Apomixis
c) Parthenocarpy
d) Parthenogenesis
ii) Nature has mechanisms to promote outbreeding in plants. Explain any two mechanisms existing in plants to promote outbreeding.
Answer (2)
The correct answer for the first question is Parthenocarpy, which refers to fruit development without fertilization. Additionally, two mechanisms that promote outbreeding in plants include dioecy and temporal separation of pollination. These adaptations encourage cross-pollination, which enhances genetic diversity within plant populations.
;
i) The development of fruit without fertilization that results in seedless fruit is known as parthenocarpy . Therefore, the correct option is c) Parthenocarpy.
Parthenocarpy is a phenomenon in which fruits are produced without the prior fertilization of ovules, leading to seedless fruits. It occurs naturally in some plants and can also be induced artificially.
ii) Nature has several mechanisms to promote outbreeding in plants to increase genetic diversity and adaptation. Here are two such mechanisms:
Dichogamy : This is a temporal mechanism where the timing of maturity of male and female reproductive organs is different within the same plant. There are two types of dichogamy: protandry, where male parts (anthers) mature before female parts (stigma), and protogyny, where female parts mature before male parts. By temporally separating the maturation of reproductive organs, plants decrease the chances of self-pollination and promote cross-pollination with other plants.
Self-Incompatibility : This is a genetic mechanism where a plant can recognize and reject its own pollen or pollen from genetically similar individuals. This process prevents self-fertilization and encourages genetic diversity by promoting cross-pollination with unrelated individuals. Self-incompatibility is achieved through specific molecular interactions between pollen and the pistil, allowing only compatible pollen to fertilize the ovules.
Both dichogamy and self-incompatibility help ensure genetic variation and resilience in plant populations by promoting outbreeding.
