Answer:
A.
Explanation:
Because they move faster then warm fronts.
Answer:
If an individual Drosophila has two or more populations of cells comprising different genotypes from one single egg then it is termed as twin spots or mosaic.
Explanation:
There might be different reasons for mosaic to occur like
Nondisjunctioning of the chromosomes
Lag in anaphase
Endoreplication
Mutations in a single cell
Mitotic recombination:
One of the major ways through which mosaic or twin spots arise is the mitotic recombination. It is also termed as somatic cross over. Twin spot or mosaic generally occurs if there is linking of heterozygous genes in repulsion. The recombination generally happens among the centromeres from the adjacent genes.
A common example of the mitotic recombination is the Bloom's syndrome. Bloom's syndrome is caused due to the mutation that occurs in the <em>blm</em> gene. As a result, there are defects in the BLM protein produced.
Answer:
C. Cytology is the study of cells, while histology is the study of tissues.
Explanation:
Answer: D) Centrioles
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Centrioles are only found in animal cells and they help during cell division. They organize the spindle fibers that help elongate the cell and separate the chromosomes.
Answer:
The correct answer is b. actors have to be more likely to carry the altruistic allele than non actors.
Explanation:
Altruism is the behavior by an organism that benefits other organisms by costing its own fitness. The actor is the individual who is doing altruism and the recipient is the individual who is getting benefited by the actor's altruism.
An example of altruistic behavior can be seen in animal kingdom easily. Vampire bats give blood to those members of the community who were not able to go for search for blood show altruistic behavior.
Actors have altruistic genes that suggest them to behave altruistically. Non-actors may not contain alleles of altruism but the recipient might have altruistic alleles.
Hamilton's rule says that natural selection will favor the altruistic allele when rb > c.
where r = coefficient of relatedness between donor and recipient
b = benefit received by recipient and
c = cost paid by altruist.
Therefore, the correct answer is b.