NEET BIOLOGY

Detailed explanation-1: -Monoecious or homothallic condition in Chara (green algae) is used to denote upper oogonium and lower antheridium on the same plant. The organisms, which possess both the reproductive organs are called bisexual. Unisexual condition represents both male or female organs in same organism.

Detailed explanation-2: -Monoecious (bisexual) plant of Chara shows occurrence of upper oogonium (female reproductive organ) and lower antheridium (male reproductive organ) on the same plant.

Detailed explanation-3: -Chara is found mostly in hard fresh water, rich in organic matter, calcium and deficient in oxygen. Chara plants are often encrusted with calcium carbonate and hence are commonly called stone wort. ADVERTISEMENTS: Chara often emits disagreeable onion like odour due to presence of sulphur compounds.

Detailed explanation-4: -Chara are monoecious organisms as both male and female reproductive structures are in the same organisms. Marchantia are dioecious as both male and female reproductive structures are in different individuals.

Detailed explanation-5: -Dioecious plants are either male or female. Each individual plant, when it produces reproductive structures, produces only male or female structures. Monoecious plants are both male and female. In gymnosperms, this means that the plant bears both male and female reproductive structures.