Answer:
8. D
9. A
10. A
11. C
12. D
Explanation:
8. Natural selection works on variation that exists in the genes of organisms. Antelopes who have genetic variation that makes their legs more muscular are at an advantage because they can outrun predators. This increases the chance that they will reach reproductive age, and be able to pass this advantageous trait onto their offspring. Over time, this selection pressure makes the variant more common in a population.
9. Beneficial traits are those that give a selective advantage. This could be one that helps it outrun predators (like above), avoid illness and death, gives it a reproductive advantage (i.e. more attractive to mates), or makes it better able to digest certain foods, for example. The formation of cancer cells would be harmful for an organism, reducing its fitness and perhaps leading to death. The inability to reproduce would mean genetic info is not passed on to the next generation, and stopping the production of an essential protein would likely lead to death. However, resistance to a virus would help an organism avoid illness and death, improving fitness.
10. Genotypes are what organisms inherit from their parents, i.e. the genetic information that is passed on. However, the way in which different alleles interact and are expressed is the phenotype. If we take the above example, natural selection is acting on the phenotype of muscular legs. If an antelope had the muscular leg genotype but for some reason it was not being expressed (maybe another gene is interfering with it), then the antelope would not have a selective advantage, and natural selection could not be act on the trait.
11. A trait that better suits an organism to its environment will be selected for by natural selection. This is because that organism is more likely to survive due to the trait, giving it a selective advantage. Therefore, if a mutation arose making the giraffe more adapted to the environment, it would be positively selected for, and through evolution would become more common.
12. This is an example of selective breeding, which has been happening for generations. Farmers spot desirable traits, and cross horses with these traits in an attempt to enhance the trait or to ensure it is passed on to the next generation. This is not natural selection, because farmers are making it happen artificially. It is not cloning or recombinant DNA, which are terms scientists use for actually manipulating the DNA in the lab.
Answer:
In the 1960s, scientists found evidence that new material is indeed erupting along mid-ocean ridges. The scientists dived to the ocean floor in Alvin, a small submarine built to withstand the crushing pressures four kilometers down in the ocean. In a ridge’s central valley, Alvin’s crew found strange rocks shaped like pillows or like toothpaste squeezed from a tube. Such rocks form only when molten material hardens quickly after erupting under water. These rocks showed that molten material has erupted again and again along the mid-ocean ridge.
When scientists studied patterns in the rocks of the ocean floor, they found more support for sea-floor spreading. You read earlier that Earth behaves like a giant magnet, with a north pole and a south pole. Surprisingly, Earth’s magnetic poles have reversed themselves many times during Earth’s history. The last reversal happened 780,000 years ago. If the magnetic poles suddenly reversed themselves today, you would find that your compass needle points south.
Explanation:
I found this somewhere.
A population is essentially just a collection of all living things in one category. People are one population, insects are another, etc. Communities are "more organized" populations. Soccer players hang out with soccer players, spiders hang out with spiders. We split into "our people" within our population.
I know that may be a little confusing, but if you have anymore questions feel free to ask. I hope I was able to help. Best of luck!
It occurred during meiosis.
just took the test, hope this helps:)
To locate <u>positions</u> in east and west directions, <u>cartographers</u> use lines of <u>longitude</u>, also known as <u>meridians</u>. Longitude is the distance in degrees <u>east</u> or <u>west</u> of the prime meridian, which is the reference point for longitude.
<h3>What is a topographic map?</h3>
A topographic map can be defined as a type of map which contains an accurate and detailed graphical (two-dimensional) description, representation or records of both natural and man-made (artificial) features on the surface of planet Earth.
Generally, a topographic map make use of contour lines to represent points of equal elevation above sea level such as:
- Mountains
- Hills
- Plains
- Valley
<h3>What is a line of longitude?</h3>
A line of longitude can be defined as an imaginary great circle of constant longitude on the surface of planet Earth which passes through the North pole (terrestrial pole) and South poles (Meridian) at right angles to the equator.
Read more on line of longitude here: brainly.com/question/17355844
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