Ecosystems need producers because they are the start of the food chain.
Producers are consumed by first consumers, the second consumers and so on.
There are 4 thing that need to happen for natural selection to occur:
1) reproduction
2)heredity
3)variation in fitness or organisms
4)variation in individual characters of the population.
Answer: Hey There! ^^
The reaction that causes a firework to explode requires less energy to start, and occurs more rapidly than the reaction that causes a candle to burn
Explanation:
! ^^
Answer:
Self-antigens are not recognized and attacked by the T cells.
Explanation:
In immunology, the antigens are those substances which are bound by the antibodies. The antigens can be originated from within the bodies, known as self antigens or from outside the body, known as non-self antigens. The immune system identifies and attacks non-self invaders or the foreign harmful objects present in the body. It does not attack the self-antigens under the normal conditions. This is due to the negative selection of T cells of the thymus.
Ribosomal RNA<span> (rRNA) associates </span>with<span> a set of </span>proteins<span> to form ribosomes. These complex structures, which physically move along an mRNA </span>molecule<span>, catalyze the assembly of amino acids into </span>protein<span> chains. They also bind tRNAs and various accessory </span>molecules<span> necessary for </span>protein<span> synthesis.</span>