Answer:
Selectively permeable or semipermeable means specific substances are allowed to pass through the plasma membrane.
Explanation:
The plasma membrane is selectively or semipermeable in nature because the plasma membrane allow only specific molecules such as nonpolar substances or hydrophobic substances such as steroidshormone to pass through it and prevent the passage of polar solute molecules such as water,glucose.
To transport these polar solutes across the membrane an additional protein is needed in case of transport of water channel protein is needed whereas in case of glucose transport carrier protein is required.
Bacteria are like eukaryotic cells in that they have cytoplasm, ribosomes, and a plasma membrane. Features that distinguish a bacterial cell from a eukaryotic cell include the circular DNA of the nucleoid, the lack of membrane-bound organelles, the cell wall of peptidoglycan, and flagella.
The roots of the plant do not make the food. Thus, the answer to this question is letter B. The roots hold the plant in place and through them the minerals and water from the soil. The roots is also involved in the vegetative reproduction and competitions with other plants.
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>.
