Answer:
False
Explanation:
Most scientists were not yet concerned about global warming. This was because the major issue during the period between 1940 and 1970 was global cooling with little or no attention on global warming.
However things started to change due to more pollution as a result of technological advances. Global warming started becoming a concern between 1970s and 1990s because of the increase in steady surface temperature.
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.
true
we will take cows as an example, they inhabit earth and so do we as humans. we as humans put the on our farms and our grass lands. we give the cows a biome. so that makes the statement true.
tell me if I am wrong. :)
