Answer:
Here are the answers:
a. 4 Cell determination as an issue in the *rest is missing*
b. 4 They assumed that different ways of separating an embryo into two parts would be equivalent as far as the fate of the two parts was concerned.
c. 4 I and III only
Explanation:
The passage demonstrates the importance of two factors in the development of an embryo: cleavage planes of division of embryonic cells and cell differentiation.
Cleavage Planes:
Cleavage basically refers to the division of the zygote into a large number of cells called blastomeres. Cleavage planes are geometrical lines or orientations along which cleavage takes place. Since, all embryonic cells are the precursors of some type of body cells, the cleavage planes determine if the cells are adequate for growth and development.
Cell Differentiation:
Cell differentiation is the transition of an undifferentiated cell into a specialized one. For example, stem cells are undifferentiated cells that develop into progenitor cells that mature into a specific cell lineage. For an embryo to regenerate, the presence of adequate embryonic stem cells is crucial. Embryonic stem cells are present in abundance before the gastrulation phase of embryonic development, after which they rapidly start differentiating.
The associations are involuntary, digestive tract and arteries >> smooth; whereas voluntary, tendons, extensors >> skeletal and electrical nodes >> cardiac.
<h3>What are muscles?</h3>
Muscles are a special type of tissue that has the ability to contract in response to a given stimulus.
There are different three types of muscle fibers: cardiac muscle, skeletal muscle and smooth muscle.
Cardiac muscle and smooth muscle are involuntary muscles, whereas skeletal muscle is a voluntary muscle.
Learn more about skeletal muscle here:
brainly.com/question/1283837
I’m looking for this too, ain’t no way your in collage learning this.
I believe it's genes. Your parents mixed genes to create you.
