Why is cleavage in mammals referred to as simple holoblastic?

Explanation

**Step-by-Step Solution:**

1. **Definition of Cleavage**: Cleavage is the process of cell division that occurs after fertilization, leading to the formation of a multicellular embryo from a single-celled zygote.

2. **Characteristics of Mammalian Eggs**: In mammals, the eggs are described as microlacetal, which means they contain a very low amount of yolk. This is significant because the amount of yolk influences the type of cleavage that occurs.

3. **Holoblastic Cleavage**: The term "holoblastic" refers to a type of cleavage where the entire egg or zygote divides completely during the cleavage process. In mammals, this means that the cleavage is not restricted to any specific part of the egg; rather, it occurs throughout the whole egg.

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