Chapter 28, Problem 1RQ

Summary Introduction

To determine:

Match the following statement with (a) cleavage or (b) gastrulation.

(1) Period during which a morula forms

(2) Period when vast amounts of cell migration occur

(3) Period when the three embryonic germ layers appear

(4) Period during which the blastocyst is formed

Answer to Problem 1RQ

Solution:

Term	Statement
Cleavage	Period during which morula forms
Gastrulation	Period when vast amounts of cell migration occur
Gastrulation	Period when the 3 embryonic germ layers appear
Cleavage	Period during which the blastocyst is formed

Explanation of Solution

(1) The blastula gets cleaved to form a solid ball of cells known as a morula. It is the early stage of the embryo that contains cells or blastomeres.

(2 and 3) Gastrulation is the method where three main germ layers, namely, the ectoderm, endoderm, and mesoderm are present in the correct topological position. A huge amount of cell migration takes place.

(4) The blastocyst refers to the structure that is formed during the early growth of the mammals. The cleavage is most commonly seen during this phase.