Answer:
true
Explanation:
stars can change bc Stars change over time. ... It is in the clouds of dust and gas that stars are born. As more and more of the gas (which is mostly hydrogen) is pulled together by gravity into a cloud, the cloud starts to spin. The gas atoms start to bump into each other faster and faster.
Answer:
Human cells can readily absorb folic acid; bacteria cells cannot.
Explanation:
Bacterial cells cannot absorb folic acid and synthesize it. On the other hand, humans do not synthesize folic acid in their cells. They rather obtain it from the diet. Sulfa drugs, for example, sulfanilamide resemble p-aminobenzoate (PABA). PABA is a molecule that is used as a substrate in the synthesis of the coenzyme folic acid. The sulfa drugs serve as competitive inhibitors and compete with PABA for the catalytic site of an enzyme involved in the folic acid synthesis. This prevents the synthesis of folic acid in bacterial cells and thereby, inhibits bacterial growth.
Answer and Explanation:
The cell division cycle is responsible for increasing and maintaining cell number and size. This cycle is an essential feature of living organisms. There are four phases of cell division mitotic phase (M phase), growth phase 1 (G1), growth phase 2 (G2), and synthesis phase (S). One phase of the cell cycle ends, and the other starts; this is named a phase transition—a unidirectional alteration in the cell cycle phases. During G1, G2, and S phase cell grows and during the M phase cell divides. There are two models of cell reproduction as the clock model and the domino model. The domino model implies that cell division phases must occur in a distinct order and at a definite time. The domino model recommends that the cell cycle events are independent, while the clock model shows that the effectiveness of mitosis entrance was not persuaded by other actions.
