Answer:
Pericardial sac has protective tole
Explanation:
Pericardial sac or pericardium is a fibrous tissue that surrounds the heart. It has two coats:
- the outter coat-parietal pericardium
- the inner coat-visceral pericardium or epicardium which is double-layered and contains pericardial fluid between those two layers (pericardial fluid is necessary as a lubricant for the heart movement).
Besides lubrication, percardium also protects heart from infections, fixes it and limits its movements.
Seed plants have an evolutionary advantage for several reasons. For one, the seeds can disperse easily. Furthermore, seeds can time their germination. For example, some seeds only germinate when they experience a period of being frozen.
Reproductive isolating mechanisms are barriers which impeded mating (prezygotic) or prevent the hybrid from developing properly (postzygotic) but the overall effect is to cause speciation by making it difficult for two diverging species to share genes. So one kind of mechanical isolation could be the usage of contraceptives. As of temporal isolation, or behavioral isolation could be exemplified by people who suffer from diseases that cause separation (such as HIV or cancer). I hope that this is the answer that you were looking for and it has helped you.
<span>a. the cell uses information from messenger rna to produce proteins.</span>
that the chromatid pairs become visible
<span>
Mitosis occurs when the nucleus of the cell divides into two identical nuclei, each with the same type and number of chromosomes. The cell's DNA is duplicated during this phase. Sometimes the cell's DNA isn't copied properly resulting in cancer-type cells. 2. Cytokinesis is when the cytoplasm divides into two identical daughter cells. Each cell is genetically identical and both are a similar size. </span>
