Answer
La corteza terrestre temprana apareció hace aproximadamente 4.500 millones de años, después de las últimas etapas de acreción planetaria.
Answer:
4. B cells become activated by interacting with helper T cells.
1. B cells display antigens in MHC class II receptors on the cell surface.
2. Antibodies released by plasma cells bind to the antigen so they will be destroyed by other cells of the immune system.
3.B cells rearrange their DNA to create a unique B-cell receptor.
5. B cells undergo clonal expansion.
6. B cells digest antigens that bind to the antibodies on their surface.
Explanation:
B-cells get activated by interacting with helper T cells when they bind to the antigen to receptors i.e (MHC class II receptors on the cell surface) on the surface of the cell. Series of activities such as release by plasma cells which cause rearrangement of B cells causes the cell to divide and proliferate. The process through which daughter cells arise from a parent cell called clonal expansion.
Answer:
They are sections of DNA that produce the proteins that control an organism's characteristics.
Explanation:
- <em><u>Genes are units of heredity found in a certain place on a chromosome and that codes for a certain product.</u></em>
- A trait of an organism is a characteristic that an organism can pass on to its offspring through its genes
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- Genes are sections of DNA that contains information which controls a trait. Therefore, a trait depends on genes. Therefore; genes are the sections or segments of DNA that code for a specific trait in organisms.
Prostaglandins are not stored in cells and are synthesized just before they are released, rapidly inactivated after their release and they are paracrine substances (Options b, c and e).
<h3>Whta are prostaglandins?</h3>
Prostaglandins are chemical substances that act as hormones by affecting surrounding cells in a tissue.
These substances (prostaglandins) are not secreted by specific glandular organs as other hormones.
Prostaglandins are substances that have fundamental functions for the normal functioning of the body.
Learn more about prostaglandins here:
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