Answer:
The behavior of chromosomes during meiosis and fertilization is responsible for most of the variation that arises in each generation. Three mechanisms contribute to genetic variation arising from sexual reproduction: independent assortment of chromosomes, crossing over, and random fertilization.
Answer: Eating excessive quantities of such molecules could deregulate this process, increasing methylation and repressing the expression of genes that should normally be expressed.
Explanation:
DNA methylation is one of the epigenetic mechanisms involved in the regulation of gene expression, because it is a process by which methyl groups are added to DNA.
Methylation then modifies the function of DNA when it is found in the promoter gene, it is essential for normal development and is associated with a number of key processes, including genomic imprinting, inactivation of the X chromosome, repression of repeating elements, aging, and carcinogenesis. Usually, <u>it acts to suppress gene transcription.</u>
For example, folic acid is essential for the rapid cell division that occurs during early fetal development and it also plays an important role in methylation and thus in gene regulation. <u>The metabolism of these vitamins is aimed at achieving adequate levels of DNA methylation, necessary for the cellular processes</u>. Eating excessive quantities of such molecules could deregulate this process, <u>increasing methylation and repressing the expression of genes that should normally be expressed</u>.
Answer:
false
Explanation:
your body needs a lot on food, materials, etc. from natural resources
<span>Let's look at all the statements:Which of the following statements is true?
Parts of an ecosystem only include biotic factors such as plants and animals. - this is not true, it also includes abiotic factors, such as stones
If a common plant in an ecosystem becomes diseased, the ecosystem may become unbalanced. - this is the true statement! it could be a source of food for other animals, and thus it could influence the population of other species
Abiotic factors include decomposers such as fungi and bacteria. - this is false, those are biotic factors.
Tundras have a high diversity of species. - this is not true - compared to the rain forest, for example, tundras are not very diverse</span>
Controlling the synthesis of proteins is the key to controlling the chemical pathways in the cell.
This is because proteins have key roles in many chemical reactions in the cell.
The most important proteins for the chemical reactions in the cell are enzymes.
Enzymes catalyze many chemical reactions, therefore, the control of the enzyme synthesis is a direct way of controlling other chemical reactions in the cell.
