B Nature selection for traits the allow for increased rates of reproduction and survival over traits that don't, is correct.
A is also correct
If less is the only option then go with that like your question suggests but more feels like a better answer
Answer:
A lot of factors cause genetic variation in a population. The root of all genetic variation is mutations, which occur randomly.
A lot of genetic variation in fact results during meiosis, the process by which gametes (sex/reproductive cells) are formed. The 3 main ways are crossing over, independent assortment of chromosomes, and random fertilization. Crossing over occurs during Prophase I of meiosis, in which genetic material is exchanged between nonsister chromatids of homologous chromosomes. Independent assortment refers to the following: When cells divide during meiosis, homologous chromosomes are randomly distributed during anaphase I, separating and segregating independently of each other. Random fertilization is where any sperm can fertilize any egg cell. The many combinations of eggs and sperms mean variation.
Another source of genetic variation include gene flow. Gene flow is where populations have their members enter other populations (migration), influencing the gene pool of populations. This source is more controversial, however.
Random mating can also increase genetic variation.
Biotic:
Animals: animals are consider biotic because they are living things, they breath, walk, eat, sleep, reproduce, and drink water. and since biotic means living things, the animals are under the biotic category.
Plants: same as animals, but with plants they reproduce asexually meaning it requires only one organism to produce another life. Anything with cells in them are consider a living thing.
bacteria: same as plants and animals, they have cells so they are consider a living thing.
There are other types of biotic factors out there like producers, consumers and decomposes. Here are the ten things of biotic:
1. Bamboo plants (producers)
2. Banana Trees (producers)
3. orchids (producers)
4. Seaweeds (producers)
5. anteater (consumers)
6. Bears (consumers)
7.zooplankton (consumers)
8.bacteria (decomposers)
9. earthworms (decomposers)
10. termites (decomposers)
Those are the ten examples of biotic.
Abiotic:
Some of the examples include temperature, sunlight, soil, gases and atmospheric, these are consider the non-living things but here are 5 examples of abiotic factors in the ecosystem.
1. Altitude
2.pollution
3.soil
4.wind
5. Ph
Hope this helped :)
Have a great day
