1. All known living things are made up of one or more cells.
2. All living cells arise from pre-existing cells by division.
3. The cell is the fundamental unit of structure and function in all living organisms.
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A single gene disorder is one that's known to be caused by a single gene. Multiple gene disorders, however, can be caused by multiple gene combinations and other factors. Dominant genes are always expressed in the offspring, while recessive genes are only expressed if the offspring recieves the recessive gene from both parents. Sex-linked genetic disorders occur most often in men, and are caused by a single-gene disorder gene being on the X chromosome but not the Y, so that the offspring needs only one recessive gene to have the trait/disorder.
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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>
In every trophic level, only 10% of energy is passed on.
Grass, with <span>30,000 kJ of energy, is eaten by a zebra.
Zebra then has 10% of 30,000 kJ from the grass, which is 3,000 kJ of energy.
Cheetah then eats the zebra, gaining only 10% of 3,000 kJ of energy of the zebra. Finally as conclusion, cheetah has 300 kJ of energy after having acquired the zebra.</span>
Answer:
Option C
Explanation:
Given -
Total number of initially marked lizards (M) 
Total number of recaptured lizards (C) 
Total number of recaptured marked lizards (R) 
As we know that -
We have to find "N" . "N" is the total population size of lizards in a 2-hectare plot in eastern Arizona.
Thus, on rearranging the above equation, we get -
Substituting the given values in above equation, we get -
Hence, option C is correct
