C) the changes reflect...
Answer:
Gonadotropins are polypeptide hormones and are secreted by the anterior pituitary gland.
Explanation:
Hypothalamus releases GnRH i.e gonadotropin releasing hormone which stimulates the anterior pituitary to secrete gonadotrophs such as FSH, ICSH and LH.
FSH (follicle stimulating hormone): In males it stimulates spermatogenesis. In females it stimulates growth of ovarian follicles.
ICSH (Interstitial cell stimulating hormone): In males, secretion of testosterone.
LH (Luteinising hormone): In femalestogether with FSH, it triggers ovulation, stimulates conversion of broken ovarian follicle into corpus luteum.
Answer:
rice cultivation.
Explanation:
There are two methods of sowing a crop in the field i. e. sowing of seed and transplanting. Seeds sowing in the field is used for almost all the crops except rice in which transplantation is done. In transplanting method, plants are grown inside a nursery and when the plant reaches to a certain height, it is transported to the field. This method is done in the cultivation of paddy rice because water is present at a certain height in the field and rice is the only crop in which roots respire in water.
Answer:
many moons
Explanation:
None of Jupiter's moons have more than traces of atmosphere, so their skies are very nearly black. ... For an observer on Io, the closest large moon to the planet, Jupiter's apparent diameter would be about 20° (38 times the visible diameter of the Moon, covering 5% of Io's sky).
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.
