Answer:
the correct answers are as follows
12:
b. Testcross- an organism with dominant phenotype but unknown genotype is crossed with homozygous recessive organism for the same trait. Based on the results obtained, if all offsprings have the same phenotype, then the parent is homozygous, but when a 1:1 ratio is observed in the offsprings, then the parent is heterozygous.
13.
e. Watson and Crick- they both used the crystallographic images from Franklin, analyzed them to first elucidate the 3D structure of the DNA and propose it to the world.
14.
c. Intracellular and commonly found in the cytoplasm- the receptors of steroid hormones are generally present within the target cell either in the cytoplasm or nucleus, since they alter gene expression.
15
e. Certain prokaryotes/bacteria- this is a process that will enable disease-causing pathogens to communicate and cooperate with their group, by the release of autoinducers that increase their cell density.
Answer:
low level of calcium would result in fewer signals sent between pre and post synaptic cells.
Explanation:
The calcium has a main role in signal transmission mechanism and here is the mechanism :
1-the impulse reaches the synapse (depolarization which is a voltage change).
2-the voltage gated calcium channels open and let calcium flow into the cell.
3-the calcium causes the synaptic vesicles to rupture and release chemical transmitters which cross the synaptic cleft and finally bind to receptors on the post synaptic cell (transmitting the signal)
so it's obvious that if calcium concentration decreases, the signal transmission also decreases.
Answer:
Option C
Explanation:
For chagarff's rule, it clearly states that DNA from any cell of any organisms be it prokaryotes or eukaryotes should have the basic 1 (purine): 1 (pyrimidine) ratio. Particularly, amount of adenine should be equal to thymine, and guanine equal to cytosine. This is in particular reference to organisms that have double stranded DNA.
The physical location of a gene within the genome is called the Locus.
