Differentiate between microsporogenesis and megasporogenesis.
Comparison of Microsporogenesis and Megasporogenesis
| S.No | Microsporogenesis | Megasporogenesis |
|---|---|---|
| 1 | In this process, haploid microspores are formed from diploid mother cells or pollen mother cells (MMC or PMC). | In this process, haploid megaspores are formed from diploid mother cells (MMC). |
| 2 | It occurs inside the microsporangium or pollen sac of an anther. | It occurs inside the nucellus of ovule or megasporangium. |
| 3 | There are many microspore mother cells in a microsporangium. | There is generally a single megaspore mother cell in a megasporangium. |
| 4 | The four microspores formed from a single microspore mother cell are generally arranged in a tetrahedral structure. | The four megaspores formed from a megaspore mother cell are arranged in the form of a linear tetrad. |
| 5 | All the four microspores arranged in a tetrahedral tetrad are functional. | Only one megaspore remains functional while the other three degenerate. |
| 6 | The microspores give rise to male gametophytes. | The functional megaspore gives rise to female gametophytes. |
Why is apple called a false fruit? Which part (s) of the flower forms the fruit?
False fruits are those fruits in which accessory floral parts also contribute to fruit formation. In apple, the thalamus also contributes to fruit formation. Therefore, it is called a false fruit. The fruit develops from the ovary of the flower.
What is apomixis and what is its importance?
Apomixis is a type of asexual reproduction that mimics sexual reproduction to form seeds without fertilisation. In apomictic seeds parental characters are maintained in the progeny/offspring as there is no meiosis or segregation of characters. If desired hybrid seeds are made apomictics the farmers can keep on using the hybrid seeds to rise new crops year after year.
What are non-albuminous and albuminous seeds?
Non- albuminous- Do not have residual endosperm as it is completely consumed during embryo development. Albuminous- The seeds retains a part of endosperm as it is not completely used up during embryo development.
