Answer:
The main idea in a given piece of reading is implied by the introductory paragraph, and, or several meaning sentences that are in subsequent paragraphs.
Explanation:
The main ideas in the a given piece of work, specifically reading is contained in the first paragraph of the piece of writing. The first paragraph can be used to imply the main ideas in a topic without necessarily revealing it. The first concepts, terms, illusion and characters mentioned, certainly we can deduce the main idea.
Several sentences in paragraphs that carry almost similar, related and interrelated facts, in most cases are very essential in explaining the main idea. By looking at them in various paragraphs, one is able to find the sole message being communicated.
The appropriate answer is D. a river floods over its channel banks and deposits sediment on the wide valley bottom.
Flood plains usually develop along the lower course of the river. The lower course has a gentle gradient and so the flow of water is not fast and therefore the bed load of the river gets deposited. Rivers carry materials such as boulders, pebbles, gravel, sand, silt and clay. The larger size materials will get deposited upstream while the finer material will travel to the lower course.
The glacier melt each year increases the volume of the river so it will overflow its banks and deposit materials in layers on the flood plains. Materials on the flood plain are usually fine such as sand and silt.
Complete question:
In the 1890s, Northern elephant seals were hunted almost to extinction. An unknown population of less than one hundred animals managed to survive on the tiny island of Guadalupe off of Mexico. The current population of over 100,000 is thought to be derived from that tiny remnant population. Compared to the Southern elephant seals (which did not experience such a bottleneck), the Northern elephant seals likely have -------- (Lower - Higher) genetic diversity and -------- (Lower - Higher) levels of genetic diseases.
Answer:
In the 1890s, Northern elephant seals were hunted almost to extinction. An unknown population of less than one hundred animals managed to survive on the tiny island of Guadalupe off of Mexico. The current population of over 100,000 is thought to be derived from that tiny remnant population. Compared to the Southern elephant seals (which did not experience such a bottleneck), the Northern elephant seals likely have Lower genetic diversity and Higher levels of genetic diseases.
Explanation:
Genetic drift is the random change that occurs in the allelic frequency of a population through generations. The magnitude of this change is inversely related to the size of the original population. These changes produced by genetic drift accumulate in time. Eventually, some alleles get lost, while some others might set. Genetic drift affects a population and reduces its size dramatically due to a disaster or pressure-bottleneck effect- or because of a population split -founder effect-.
In the exposed example, extensive hunting acted as a pressure that reduced the number of Northern elephant seals to fewer than 100. This population experienced one or many generations of small size since these animals were affected by hunting. As the survivors did not have the whole genetic pool of the original population, the population size might have recovered to a current population size of 1000,000 individuals, but <u>the genetic pool might have not</u>. When the small population increases in size, it will have a genetically different composition from the original one. In these situations, there is a<u> reduced genetic variability</u>, with a possibility of developing a peculiar allelic component. If the survivors in the population carried or developed a mutation, probably this mutation passed from generation to generation. It will involve more individuals each time and<u> increase the probability of developing a genetic disease</u>.
Answer:
it is a cell.
Explanation:
the cell is the structural and functional unit of all living organisms
<span>Endoplasmic reticulum (ER) is a network of interconnected sacs (cisternae). Depending on the presence of ribosomes on the surface of their membrane, ER can be rough or smooth. Smooth ER does not have ribosomes on the surface of its membrane. Smooth ER plays a part in lipid production and metabolism, as well as in the production of steroid hormones. It is also involved in detoxification of organic chemicals, products of natural metabolism, etc.</span>
