There are THREE (3) phyla or categories of fish.
These phyla are:
1) Agnatha - jawless fish ; around 50 species in the world
2) <span>Chrondrichthyes - cartilaginous fish ; around 600 species in the world
3) </span><span>Osteichthyes - bony fish (divided into ray finned group and lobe finned group) ; around 30,000 species in the world.
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B.) CO2 that is the chemical formula for carbon dioxide
Answer:
the answer to this question is C.. prokaryotic cells
The type of immunity that provides lifetime immunity for the body against a specific pathogen is called acquired immunity. It is also referred to as adaptive or specific immunity.
Acquired immunity is not present at birth. it is learned. As a person's immune system encounters foreign substances (antigens) the components of acquired immunity learn the best way to attack each antigen and begin to develop a memory for that antigen. Acquired immunity is also called specific immunity because it tailors its attack to a specific antigen previously encountered. Its uniqueness lies in its ability to learn, adapt and remember.
Acquired immunity takes time to develop after first exposure to a new antigen. However afterward, the antigen is remembered, and subsequent responses to that antigen are quicker and more effective than those that occurred after first exposure. Memory of a particular antigen is kept by the B and T lymphocytes.
Answer:
A step that is not part of natural selection is people select which individuals breed and which ones do not.
Explanation:
Natural selection is a process in which favorable or unfavorable environmental conditions determine the evolution of species, producing differences in their genotype over a long period of time.
As its name indicates, it is a natural selection, in which no intervention by people is contemplated, so that <u>people cannot determine which individuals breed</u>.
Natural selection implies that the characteristics on which the environment influences are inheritable, that there is genetic variability in the population and that the variability of these characteristics implies the ease of reproduction and survival capacity.
<em>The other options do form part of natural selection, since they are based on the three premises of this process:
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- <em>Inheritable characteristics.
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- <em>Genetic variability.
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- <em>The variability of characteristics influences reproduction and survival.</em>
