I think that the answer this question would have to be c
Answer:
Answer is D.
Explanation:
The first cleavage division can be explained or described as the series of first cellular division of the zygote after fertilization.
In this case, the process of recoiling of the shell of the snail can not be categorized as one of the examples at this stage.
Answer:
Endocardium
Explanation:
The endocardium makes the innermost lining of the wall of the heart. It is present over the thin layer of connective tissue. The function of the endocardium is to provide a smooth lining for the chambers of the heart. The valves present in the heart also have endocardium. The dense connective tissue of the heart valves is covered by endocardium.
The presence of the smooth endocardium made up of endothelium reduces the surface friction as blood passes through the heart. The endocardium of heart chambers is continuous with the endothelial lining of the large blood vessels that are attached to the heart.