Answer:
first one is c and the second is d.
Explanation:
Answer:
The correct answer is - 2n = 41 chromosomes.
Explanation:
It is given that the cat has a diploid chromosome number of 38 while the rabbit has a diploid number of 44 chromosomes and if they form a hybrid then their expected chromosome number in somatic cells would be -
Cat (2n=38) produces haploid gametes with 19 chromosomes (n-19).
Rabbit (2n=44) produces haploid gametes with 22 chromosomes(n=22)
19+22= 41 chromosomes in the particular hybrid as half number of chromosomes come from each parent.
Answer: C
Explanation: Thymine pairs with Adenine and Cytosine pairs with Guanine.
Answer:
B, A fossil found in rocks from one time period
Explanation:
Fossils are used to determine the ages of rock layers. Index fossils are the most useful for this. Index fossils are of organisms that lived over a wide area. They lived for a fairly short period of time. An index fossil allows a scientist to determine the age of the rock it is in. Hope that this helps you :)
Answer:
True
Explanation:
Some deviations from normal homeostasis activate the positive feedback loops to control the conditions which are otherwise regulated by negative feedback mechanisms.
For example, the blood levels of respiratory gases and H+ ions are regulated by a negative feedback system via chemoreceptors. The increased partial pressure of carbon dioxide gas and lowered pH or lowered partial pressure of oxygen in the blood are sense by central and peripheral chemoreceptors which in turn activate the neurons of the dorsal respiratory group (DRG).
The activated DRG triggers an increased in the rate and depth of the breathing to facilitate the inhalation of more oxygen and exhalation of CO2 to restore the normal levels.
However, hypocapnia inactivates the chemoreceptors and does not allow negative feedback to restore the normal CO2 levels in the blood.
Under such conditions, the positive feedback loop stimulates the DRG neurons more strongly in response to the increased partial pressure of CO2 above the normal levels than when the partial pressure of oxygen falls below the normal level. These dangerously lowered oxygen levels may also cause fainting.
