those are nucleotides
since all three of them contain deoxyribose (because there's only one hydroxil group) they are DNA nucleotides
the first nucleotide has cytosine as it's nitrogenous base
the second nucleotide has adenine as it's nitrogenous base
the third nucleotide has thymine as it's nitrogenous base
<span>Cytotoxic t-cell subpopulations are specialized to combat intracellular pathogens, whereas helper t-cell subpopulations are specialized to combat extracellular pathogens.
</span>Cytotoxic t-cell are CD8+ cells. Cytotoxic t-cell uses granzymes to <span>kill </span><span>intracellular bacteria, that lives in the cytosol such as viruses. They identify the pathogen forgein peptids that are bounded to MHC-I on the cell surface.
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cd4+ T helper (Th) cells include Th1, Th2, and Th17 cells. They contribute to aliergic reactions and fighting extracellular parasites.
Answer: Flexible springs
Explanation:
The atoms in an element or compound are bonded together by bonds which keeps the atoms together.
The bonds is stiff but it proves some flexibility for the movement of the atoms so that they can react and form different types of substances.
The bonds between the atoms act like flexible spring which keeps two or more atoms together and flexible for reacting.
Answer:
An ecosystem is biotic, not abiotic.
Explanation:
First, an ecosystem is a biological community of interacting organisms and their physical environment. Second biotic factors are nonliving things whereas biotic factors are living things in an ecosystem you have your producers or plants which then will be consumed by the primary consumers. With the primary consumers feeding the next group of consumers and then the next and then after they die they fertilize the ground allowing the producers to grow as it completes the circle of life.
