Option D – amphibians may use their skin for gas exchange is the characteristic feature of amphibians that differs from reptiles.
Explanation:
The amphibian skin is moist, thin and marbled and supplied by blood vessels running on its surface. The moisture present in the skin dissolves the oxygen present in its surrounding which is absorbed by the blood vessels. Special glands help the amphibians to keep the skin moist.
The very thick and tough scales present on the reptiles prevent them to absorb oxygen through their skin. Hence, they breathe and respire through their lungs.
Amphibians have three-chambered heart. They do not develop amniotic eggs. Adult amphibians although spend much time on land, they breed only in water due to the absence of amniotic sac
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Let us go over the definitions and the functions of each term:
a) Gene is a bit vague but in general it means a part of DNA that encodes one protein. Genes are the building blocks of our genomes but not the answer to this question.
b)mRNA. This is correct. The name itself means messengerRNA and its role is to copy the genetic information in the nucleus and bring it outside to be translated into protein.
c) ATP is an important molecule in our metabolism; energy is stored in this molecule and then used. It has no relationship to the mechanisms concerning DNA.
d) Thymine is one of the 4 nucleotide bases that are found in DNA, the other three being guanine, cytosine and adenine. They are essential components of a nucleotide (building blocks of DNA and RNA) but again, they do not transfer information out of the nucleus.
When it nears the sun, due to the power of solar wind
DNA analysis helps scientists classify similar animals by the evidence of relatedness in general the more derived genetic characters to organisms share the more closely repeated they are...In other words “DNA helps scientists by comparing the similarities in each animal/person’s DNA.
Aneuploidy can result in the final daughter cell if the spindle fibers fail to pull a chromosome toward the pole as in case of non-disjunction.
Explanation:
Aneuploidy is a condition which arises when one or more chromosome is missing in the final daughter cells.
Non-disjunction refers to the failure of chromosomal or chromatid segregation or separation during cell division. This results in erroneous meiosis or mitosis leading to the formation of final daughter cells or gametes with an extra or missing chromosome. This condition is aneuploidy.
Failure of separation or segregation of:
- Homologous chromosomes occur in Anaphase I, affects four daughter cells.
- Sister chromatids during Anaphase II, affects two daughter cells
This failure of separation leads to aneuploidy chromosomal abnormalities like monosomy, trisomy, etc which can cause diseases like Down’s syndrome, Turner’s syndrome etc.
