Shallow groove on the surface of the cortex is called sulcus.
Cortex means the outer layer of an inner organ. The outer layer of the cerebrum is called cerebral cortex, where cerebrum occupies the biggest part of the brain. A human being has four lobes of the cerebral cortex which include temporal lobe, parietal lobe, occipital lobe, and frontal lobe.
Cortex has six layers of different types of neurons which are responsible for higher information processing and thinking. Cerebral cortex controls general movement, behavioural reactions, perception and visceral functions. We term the grooved layer as the brain itself.Cerebral cortex consists of large amounts of sulci and gyri(sulcus and gyri in singular). The number of gyri correlates to the processing ability of the animal.A man has big gyri compared to a rat.
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.
The right answer is B.
Insulin is a hormone naturally secreted by the pancreas, specifically by specialized cells located in the islets of Langerhans. It allows glucose (sugar) to pass blood into the cells of the body. These will use glucose as energy or store it for future use.
In healthy subjects, insulin is secreted continuously. The body produces insulin according to the needs and foods consumed. For example, after a meal, the pancreas secretes additional insulin, allowing blood glucose to stay within normal limits.
<h3><u>Answer;</u></h3>
That parental traits that were not observed in the F1 reappeared in the F2.
<h3><u>Explanation</u>;</h3>
- Mendel accounted for the observation that traits which had disappeared in the F1 generation reappeared in the F2 generation by proposing that traits can be dominant or recessive, and the recessive traits were obscured by the dominant ones in the F1.
- <em>I</em><u><em>t was important that Mendel examined not just the F1 generation in his breeding experiments, but the F2 generation as well, because parental traits that were not observed in the F1 reappeared in the F2.</em></u>
