Like you might have studied. Heated hair expands while colder air contracts. So, the sound isn't able to move as efficiently in cold air than it would in warmer air.
Apparent magnitude : How bright a star appears to be
Absolute magnitude : How bright the star actually is
I think the answer is : A. close to earth
The stars only seems to be bright because its radiated from a close distance
hope this helps
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.
Years would be the independent variable because any sort of time is usually the independent variable.
