In which of the following plants does Polyembryony commonly occur?
In many Citrus and Mango varieties, nucellar cells develop into embryos. Occurrence of more than one embryo in a seed is referred to as polyembryony.
Question 42 of 501
📘 CLASS XII
Removal of anthers from a flower bud before dehiscence is called:
If the female parent bears bisexual flowers, removal of anthers from the flower bud before the anther dehisces is necessary. This step is referred to as emasculation.
Question 43 of 501
📘 CLASS XII
The innermost wall layer of a microsporangium is usually:
The microsporangium is generally surrounded by four wall layers. The innermost wall layer is the tapetum.
Question 44 of 501
📘 CLASS XII
Which cell of the pollen grain has abundant food reserve and a large irregularly shaped nucleus?
The vegetative cell is bigger, has abundant food reserve and a large irregularly shaped nucleus.
Question 45 of 501
📘 CLASS XII
The generative cell of a pollen grain is:
The generative cell is small and floats in the cytoplasm of the vegetative cell. It is spindle shaped with dense cytoplasm and a nucleus.
Question 46 of 501
📘 CLASS XII
Pollen viability in Rice and Wheat is approximately:
In some cereals such as rice and wheat, pollen grains lose viability within 30 minutes of their release.
Question 47 of 501
📘 CLASS XII
Which family typically maintains pollen viability for months?
In some members of Rosaceae, Leguminoseae and Solanaceae, they maintain viability for months.
Question 48 of 501
📘 CLASS XII
A multicarpellary, apocarpous gynoecium is found in:
The pistils may be free (apocarpous) as in Michelia. Papaver has a syncarpous pistil.
Question 49 of 501
📘 CLASS XII
The protective envelopes of the ovule are called:
Each ovule has one or two protective envelopes called integuments.
Question 50 of 501
📘 CLASS XII
The mass of cells enclosed within the integuments having abundant reserve food material is:
Enclosed within the integuments is a mass of cells called the nucellus. Cells of the nucellus have abundant reserve food materials.
