Answer:
The correct answer is cell organelles.
Explanation:
A unique membrane-bound composition, which is found inside the eukaryotic cell's cytoplasm, that is, in plants and animal cells is termed as cell organelle. Some of the examples of cell organelles found within the cells of eukaryotes are endoplasmic reticulum, Golgi complex, mitochondria, chloroplast, etc.
All these organelles play an essential function for the proper functioning of the cell, like chloroplasts found in plants play an essential role in the process of photosynthesis, and mitochondria both in plants and animals are regarded as the powerhouse of the cell.
Endocytosis is an energy-using process. The answer is A.
Gel electrophoresis is a technique used to separate DNA fragments according to their size. This is from Khan academy so I believe it is reliable.
Answer:
by the movement of electricity
Answer:
C) Through genomic imprinting, methylation regulates expression of the paternal copy of the gene in the brain.
Explanation:
The pattern of gene expression wherein either paternal or maternal gene is expressed in specific cells while the other one is prevented from expression is known as genomic imprinting.
In the given example, the maternal copy of the gene on chromosome 15 is expressed in brain cells while its paternal copy is not expressed in these cells. Hence, the pattern of expression of this gene is regulated through genome imprinting. One of the mechanism is methylation of cytidine residues of CpG islands of the DNA that are more frequently present within promoters of the genes.
When the cytidine residues of these sequences are methylated into 5-methylcytidine, the transcription factors do not bind to these promoters preventing the expression of these genes.
Hence, methylation of cytidine residue in CpG islands of the promoters of the gene present on chromosome 15 could have silenced its expression in brain cells.
