Question

a) Coconut palm is monoecious, while date palm is dioecious. Why are they so called?
b) Draw a labelled diagram of sectional view of a mature embryo sac of an angiosperm.

Answer 1

Hint: When the concepts of the Latin prefixes di and mono are understood, the meanings of the two words can be readily understood. Di refers to 'two' and ’one’ refers to mono. These two concepts are mainly used to characterize sexuality.

Complete answer:
To describe some reproductive behaviour of plants, the terms monoecious and dioecious are used. Both male and female reproductive organs are found in the same plant in some plant species, but in some plants, male and female reproductive systems are housed in different individuals. The main distinction between monoecious and dioecious is that monoecious describes in the same plant or animal that having both male and female reproductive systems, while dioecious describes plants or animals having male and female reproductive systems in separate individuals.
The female angiosperm gametophyte is named as the embryo sac which is small and comprises a few (usually eight) nuclei; no cell walls separate the cytoplasm and the cytoplasm can directly associate with these nuclei.
a) Both male and female flowers grow on the same individual in the coconut palm. This state is referred to as monoecious. The male and female flowers grow on separate individuals in the date palm. This state is referred to as dioecious.
b)

Note:The monoecious plants are also known as homothallic and dioecious plants are known as heterothallic. To describe their sexual reproduction, monoecious and dioecious terms are used primarily, though not exclusively, in relation to bryophytes. Bryophytes have a powerful and dominant class of gametophytes.