The correct terms to fill in the blanks are lateral ventricles and venous sinus blood. Cerebrospinal fluid (CSF) is formed by lateral ventricles and reabsorbed through arachnoid granulations into the venous sinus blood. The CSF is a fluid that is clear and colorless found in the spinal cord and in the brain, generally the central nervous system. The CSF functions as a buffer or a shock absorber for the brain. It provides basic mechanical protection for the brain. Also, it helps in the circulation of nutrients and the chemicals that are filtered and aids in the elimination of waste products.
Answer:
b. Cities like New York, New Orleans, and Miami will be flooded by ocean water.
Explanation:
The theory says global warming will cause the temperature of the planetary atmosphere to rise. The hotter environment will make ice masses of Greenland, and the poles to melt completely and make coastal cities like New York, New Orleans, and Miami flooded by the ocean.
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.
Starting from the outer part:
•Tunica externa (fibrous layer)
•Tunica media (smooth muscle)
•Tunica intima (endothelial cells layer)
