Answer:
1) True
Explanation:
Cells of Sinoatrial (SA) node make up the auto rhythmic cells of heart as in normal physiological conditions , SA-node is responsible to set the pace of the rest of the heart (pacemaker) at a rate of 70 to 80 beats per minute.
The cells of SA node has the ability to self-excite thus able to generate action potential without external stimulation by nerve cells. Thus they initiate the cardiac cycle providing the conduction system.
Hence the statement , SA nodal cells are unique in that they exhibit autorhythmicity, meaning they are capable of depolarizing and firing an action potential spontaneously without any external influence, is true.
<h2>X linked dominant </h2>
Explanation:
In X linked dominant if the father carries the abnormal X gene,all of his daughters will have the disease because daughters always inherit their father's X chromosome and if the mother carries the abnormal X gene, half of all their children (daughters and sons) will inherit the disease tendency
- In this case man is the one who is diseased and female is normal so daughters in this case will surely inherit the disease
- When a cross is made,all the sons are normal whereas daughters are diseased
Wow that's a good one :). Think about it like this. When you put antibiotics in place where bacterias live, probably most of them will die, however there might be "some" who are resistent to the antibiotic by their nature, (mutations etc.) so among the bacterias which were exposed the antibiotics those resistent ones will survive. And bacterias have a system for exchanging DNA to make each other more resistant, its called "conjugation" look it up. By conjugation they give each other genes which will help them survive. So if we summarize, those who are already resistant survive (which is a cause of natural selection in an environment of antibiotics) and help others resistant too.
<h2>Incomplete dominance & Co dominance</h2>
Explanation:
- Twist- The mutant allele is prevailing to its relating wild-type allele.
- forked-the mutant allele is predominant to its relating wild-type allele.
- Pale-The mutant allele is neither prevailing nor totally passive to its comparing wild-type allele.
- Mendel's outcomes were earth shattering halfway in light of the fact that they repudiated the (at that point well known) thought that guardians' attributes were for all time mixed in their posterity. At times, the phenotype of a heterozygous living being can really be a mix between the phenotypes of its homozygous guardians.
- Closely identified with inadequate predominance is codominance, in which the two alleles are all the while communicated in the heterozygote.
- Hence, the twist mutations are codominant allels at same locus.
Answer:
B I Took The Test An My teacher Say It Right
Explanation:
