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.
Answer:
e. secretion, absorption and chemical protection
Explanation:
Epithelial tissues is responsible for the protection of the skin, absorption of nutrients during digestion and secretion of waste materials. These tissues form covering to all body surfaces. They also perform a variety of other functions such as excretion of waste substances, filtration of air from dirt and particles and clean the air that is inhaled, diffusion, and sensory reception.
Answer:
the somatic nervous system and the autonomic nervous system
Explanation:
The somatic nervous system is responsible for both sending and receiving sensory and motor information to the central nervous system.
The autonomic nervous system is responsible for regulating involuntary body functions. For example, heart rate, breathing, and digestion.
They are a very good example of mutualism in which each species benefits. Please mark Brainliest!!!
Deep water has <span>a wavelength of two meters forms in water with a depth of twenty meters.</span>
