Answer:
Sickle cell disease is due to a type of substitution mutation.
Explanation:
Sickle cell disease is a condition that is transmitted from parents to children in an autosomal recessive inheritance pattern. It is due to a mutation that is capable of altering the shape of the erythrocyte, as well as its ability to circulate and carry oxygen.
The mutation that occurs in sickle cell disease is due to an alteration in the β-chain of hemoglobin, caused by the substitution of thymine base by adenine in the DNA that determines it. As a result, valine replaces glutamic acid in the β-chain amino acid sequence, with the consequences described.
- <em>The other options are not correct because </em><u><em>deletion, duplication and translocation </em></u><em>correspond to chromosomal mutations, not responsible for sickle cell disease.</em>
: Here are some learning activities and ... Which state has more miles of sandy beach<span> than any </span>other<span> state?</span>
Answer:
33
Explanation:
Gametes (sperm or egg) have half the chromosome of a diploid cell. That's why they are haploid cells.
If chromosomes come from a cell with 66 chromosomes, sperm will have 66/2 = 33.
That's why us humans have 46 chromosomes, but our egg or sperm has only 46/2 = 23 chromosomes.
Answer:
True
Explanation:
Normal flora are microorganisms that are regarded as resident organisms, which can be found on or in an individual and do not cause any disease.
the transient flora refers to microorganisms that are found on the skin or the hands which are there through direct contact with person or object, and are easily removed by routine hand hygiene. Example is Norovirus that can cause stomach flu.
Opportunistic pathogens are microorganisms such as the bacteria and virus, which can only cause infection when the immune system is down. This means that , these organisms can not cause any infection as long as the immune system is ok.
In this case, the normal and transient flora like Norovirus can only cause infection when the immune system is down. That is why they are regarded as opportunistic pathogens.
Answer:
Optic chiasma
Explanation:
Optic chiasma is the part of the brain where the optic nerves partially cross.
For example, the optic nerve fibres on the nasal sides of each retina cross over to the opposite side of the brain at the site of optic chiasm. The same thing is with the opposite site. Since the fibres intersect at the chiasm, it has the hallmark X-shape.
