Question

Human eggs are microlecithal. Give a reason.

Answer 1

Hint: In humans, the male gamete is called sperm and female gamete is called egg. The female gamete has a perfect cell body along with nucleus and cytoplasm while male gamete has a pointed head and a propelling tail at its back. They are obviously very small in size.

Complete solution:
Broadly, reproductive eggs have been divided into three categories depending upon the amount of its yolk (semi- liquid substance found in the middle part of the egg that is responsible for nutrifying the zygote). These are:
Microlecithal eggs: these eggs are typical in structure. They have a little amount of yolk in their cytoplasm.
Mesolecithal eggs: these eggs are medium in size however bigger than microlecithal eggs. They also have some amount of yolk in proportion to their size. Eggs of mammals are the example of mesolecithal eggs.
Macrolecithal eggs: these are large sized eggs. They have a large amount of yolk concentrated in the cytoplasm. Eggs if this category are bigger than those of the latter two categories.
However, this classification pattern was basically used to categorise the eggs of chordates but is capable enough of including eggs of most of the species on a broader scale.

Note:
In humans, the female reproductive gamete can be termed as a typical egg. Its cytoplasm consists of the nucleus that has female genetic material, along with a medium amount of yolk. As the human egg is found to have a subsequent amount of yolk in proportion to its cytoplasm, exactly like that of mesolecithal eggs. Therefore, human eggs can also be termed as mesolecithal eggs.