In radiation, we don't need medium to conduct heat or energy but in conduction we need medium to conduct energy or heat ! conduction is done by contact as in radiation there is no contact !
for example or any info, comment !
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:
B, C, Dand E are all correct
Explanation:
Why B is correct- The cell membrane, also known as the plasma membrane, is a double layer of lipids and proteins that surrounds a cell and separates the cytoplasm (the contents of the cell) from its surrounding environment. It is selectively permeable, which means that it only lets certain molecules enter and exit.
Plants, animals, and bacteria have a cell membrane. Why d is correcect
Why C is correct- The cell membrane is not a solid structure. It is made of millions of smaller molecules that create a flexible and porous container. Proteins and phospholipids make up most of the membrane structure.
Why E is correct- The plasma membrane is primarily composed of phospholipids arranged in a bilayer, with the hydrophobic tails on the interior of the membrane, and the hydrophilic heads pointing outwards
Why A Is Not correct- It is very fragile and its role is to hold the cell together and to help control what substances can get in and out. It is partially permeable, allowing only some substances to pass through it. The membrane has a complex structure consisting of a phospholipid bi-layer and different types of proteins.
Given the age of the meteorite is 4.5 billion years old with 78 atoms of lead-206 the answer should be B. 156. The half-life of uranium-238 in order to decay into lead-206 is 4.46 billion years, which means that the original number of atoms is 156.