Energy from sunlight is captured
The human immunodeficiency virus (HIV) that causes the disease known as aids selectively infects helper T cells (CD4+).
This retrovirus also infects macrophages and dendritic cells. When CD4+ T cell numbers decrease below a critical level (due to the killing of this cells with different mechanisms), cell-mediated immunity is lost. As a result, the body becomes progressively more susceptible to infections, leading to the development of AIDS.
<span> HIV can be transmitted only via body fluids like blood, semen, pre-seminal fluid, rectal fluids, vaginal fluids, and breast milk, which means that people usually get or transmit HIV through sexual behaviours and use of the needle. For HIV infection, these fluids must come in direct contact with a mucous membrane or damaged tissue. Another way is to be directly injected into the bloodstream (from a needle for example).</span>
Answer:
a short-term change a long-term change death adaptation. A long-term change would most likely cause a forced migration due to loss of habitat. A long-term change would most likely cause a forced migration due to loss of habitat.
Explanation:
Answer:
The correct answer is allopatric speciation.
Explanation:
Allopatric speciation occurs when a geographical barrier comes between a species population living in the same area. This geographical barrier separates the population into two different geographical area which do not have the same condition.
So as both the separated population get different habitat environment to live so they evolve differently from each other. So natural selection and genetic drift works differently in both the population which brings genetic changes in the population and helps in creating a new species.
Answer:
The correct answer would be B. semi-permeable.
Plasma membrane of any cell including red blood cell is semi-permeable in nature as it is made up of lipid bilayer.
It permits the passage of certain substances across the membrane while it blocks other substances.
Gases, small uncharged or non-polar substances such as oxygen, carbon dioxide, et cetera can easily pass through the cell membrane of a cell.
Large or charged molecules such as proteins, sodium ions, potassium ions et cetera can not pass through the cell membrane. They require carrier proteins to pass through the membrane.
