<span>The trilobites seen in this image was once found widespread in the ocean. Something Changed To Limit and finally abolish their success. What do scientists use this example as proof of ? The answers are A. life changes over time and B. Vesitigial organisms once had a function in ancient times.The trilobites first appeared in the Cambrian period and though they entered a decline int the Devonian period, some of them survived until Permian time or for a period of 270 million years. They were divided into 3 segments and were early examples of arthropods. They tended to live on or near the bottom of the oceans and were scavengers in part and as well as living on the ocean floor some swam and fed on plankton. </span>
Answer:
1. Stabilizing Selection
2. Directional Selection
3. Disruptive Selection
Explanation:
Stabilizing Selection
This type of natural selection occurs when there are selective pressures working against two extremes of a trait and therefore the intermediate or “middle” trait is selected for. If we look at a distribution of traits in the population, it is noticeable that a standard distribution is followed:
Example: For a plant, the plants that are very tall are exposed to more wind and are at risk of being blown over. The plants that are very short fail to get enough sunlight to prosper. Therefore, the plants that are a middle height between the two get both enough sunlight and protection from the wind.
Directional Selection
This type of natural selection occurs when selective pressures are working in favour of one extreme of a trait. Therefore when looking at a distribution of traits in a population, a graph tends to lean more to one side:
Example: Giraffes with the longest necks are able to reach more leaves to each. Selective pressures will work in the advantage of the longer neck giraffes and therefore the distribution of the trait within the population will shift towards the longer neck trait.
Disruptive Selection
This type of natural selection occurs when selective pressures are working in favour of the two extremes and against the intermediate trait. This type of selection is not as common. When looking at a trait distribution, there are two higher peaks on both ends with a minimum in the middle as such:
Example: An area that has black, white and grey bunnies contains both black and white rocks. Both the traits for white and black will be favored by natural selection since they both prove useful for camouflage. The intermediate trait of grey does not prove as useful and therefore selective pressures act against the trait.
A codon is a sequence of three bases found on the messenger RNA (mRNA) molecule which is translated to produce an amino acid. Each amino acid is coded by one or more specific codons. If the codon is changed through a mutation, the amino acid produced may be different. However, in this case, the other codons that produce Leucine are:
UUA, UUG, CUU, CUC, CUA and CUG
So the code CUU could mutate to CUC, CUA or CUG and leucine would still be produced.
The idea it can describe is that it is the transfer of information from one neuron to another.
<h3>Transfer of information </h3>
The nervous system is part of the body systems that helps in the transfer of information from nerve to nerve and from nerve to muscle tissues.
The presynaptic nerve is the nerve that sends the information that is to be conveyed in form of action potential impulses.
The impulses led to the release of neurotransmitters from the terminal of the presynaptic nerve to the synapse. This binds to the receptor if the postsynaptic cell which receives the message.
Learn more about neurotransmitters here:
brainly.com/question/840056
Butter, lard and beef fat are all rich in unsaturated fats :)
