Answer:
d. transcription factors
Explanation:
Transcription factors are the proteins present in cells that are involved in the regulation of gene expression. The transcription factors may increase or decrease the expression of a gene. Therefore, a transcription factor may serve as an activator or repressor for a gene. These proteins bind to a regulatory sequence present near or within a gene, interact with RNA polymerase or other transcription factors and thereby, affect the transcription initiation.
Since binding of dioxin to certain proteins alter the pattern of gene expression in the cells, these proteins are the transcription factors. For instance, dioxin may bind to a transcription factor and up-regulate the expression of genes which in turn regulate the cell division.
Answer:
Bb, Db
, Bd and Dd
Explanation:
When a cross between two parents (having certain trait) is carried out , they share their alleles with each other to produce offspring with new traits. These offspring have gentically different allele combination as compared to their parents. A genetic cross can be represented by a punnet square (as given below)
The cross between two parents with genotype "BD" and "bd" will result into the following offspring -
B D
b Bb Db
d Bd Dd
1. Rhythm generators (SA node)
2. Conductive cells (node cells)
3. Contractile cells (myocardial cells)
Answer:
Malignant melanoma cells would have active telomerases that constantly replenish and lengthen telomeres.
Explanation:
Telomerase can be described as enzymes which add the repetitive sequences called telomeres at the end of a chromosome. Telomeres can be described as repetitive sequences at the end of the chromosome which are involved in protecting the chromosome from any damage.
In a normal skin cell, the telomeres will shorten with time. But in a malignant skin cell, the telomerase will add the repetitive sequence again and again. The telomers will not be able to shorten.
Explanation:
It sends message directly to muscles and glands
