Answer:
The nucleus is an organelle found in eukaryotic cells.
Explanation:
Answer:
The independent variable are the vitamins .
The dependent variable are the rats.
Explanation:
The vitamins are the independent variable because they are are controllable. You can control how many vitamins the rats will be given.
Answer:
Type II cells
Explanation:
Type II alveolar cells are the round-shaped or cuboidal epithelial cells. These cells have a free surface with microvilli. The function of the type II alveolar cells is to secrete the alveolar fluid to keep the surface of the cells moist.
A mixture of phospholipids and lipoproteins is present in the alveolar fluid that serves as surfactant and reduces the surface tension of the alveolar fluid. The overall effect of the presence of surfactant in alveolar fluid is to protect the alveoli against collapsing during exhalation.
The right answer is D (less responsive to antigens)
It is proven that, after puberty, thymus activity (an organ that is included in the lymphatic system, producing T cells that pick up antigens) decreases and that in adult and aged people the thymus has no role. Work done in humans indicate that in fact the cellularity begins to decline from birth in favor of lymphocyte perivascular spaces and connective and adipose tissue, which leads to a decrease in the capture of antigens.
Birds have great vision and can see throughout night and day
