Answer:
Fevers are caused by chemicals in the bloodstream called pyrogens. Pyrogens make their way to the brain's hypothalamus, which is in charge of regulating body temperature. When those pyrogens bind to certain receptors in the hypothalamus, the body temperature rises.
Explanation:
Answer:
In heterozygotic individuals, the gene for sickle cell anemia is protective against malaria.
Explanation:
Through the same mechanism that the mutation associated with sickle cell anemia produces the disease (altered hemoglobin structure), having a single copy of the mutation (that is, being heterozygotic) provides protection against malaria. This is believed to be due to the altered structure causing difficulty for the malaria parasite when it attempts to enter red blood cells as part of its life cycle.
Today, there are medications to successfully treat malaria, but it still killed 627,000 people in 2020. This represents a significant evolutionary pressure for genes that would prevent serious malarial illnesses. As malaria was and still is common in African regions, the result was a higher prevalence of sickle cell anemia in those of African descent.
Answer:
The two main types of DNA organization present in chromosomes are the extended DNI and the condensed DNI
Explanation:
In eukaryotes, the complete chromosome is composed of only one lineal and extremely long DNA molecule. DNA is intimately associated with two types of proteins: <u><em>histones</em></u>, which are structural proteins, and <em>non-histone</em> proteins that mediate different functions of DNA.
DNA associated with histones is called <u><em>chromatin</em></u>. Histones are responsible for packaging DNA molecule, and the fundamental unit of packaging is known as a <em><u>nucleosome</u></em>. As chromatin must be condensed, nucleosomes generate regular structures between themselves forming a <em><u>chromatinic fiber</u></em>, in which DNA is very condensed. A superior level of condensation is the structural <em><u>ringlet-shaped domain</u></em>. At this level, a chromatinic fiber is folded and a protein is responsible for keeping joined the two regions of DNA that form the ringlet. The next condensation level is the rolling of the ringlet-shaped domain composing the <u><em>chromosome</em></u>. The typical chromosome in the metaphase is formed by <u><em>two chromatids</em></u> joined by a centromere. Each chromatid is composed of a sequence of chromatin ringlets domains. In the interphase, <em>before cellular division</em>, chromatin is in a diffuse, lax, uncondensed state, known as extended DNA. When <em>cellular division</em> is about to happen, chromatin begins to condensate. At the beginning of the <em>prophase</em>, DNA is condensed in a well-defined chromosome formed by two sisters chromatids.
Answer:
a
Explanation:
it would be a silkworm because they feed exclusively on animal fibers such as wool. hope this helps!