Answer:
b. help retain moisture in terrestrial habitats
Explanation:
Arthropods such as cockroach, centipedes, spiders, crab are the members of the largest phylum Arthropoda. These are animals with paired jointed legs and their body is covered with an exoskeleton made of chitin. They live in diversified habitat and exoskeleton helps to retain moisture in theterrestrial habitats.
Similarly mollusks such as sepia, snail are soft bodied animal whose body is covered with calcareous shell as a protection and to retain moisture while living on land.
The allele which has light color appears to be altering transcription and that is why the corresponding mRNA is absent in zebrafish which is homozygous. The protein we can say were absent because mRNA which is being required for protein synthesis it was not present.
If the allele had altered translation, mRNA which is functional would have been present but in the same case, the protein will still be absent.
Answer:
B
Explanation:
Erosion displaces sediment.
The answer is stabilizing selection.
<span>Sickle-cell anemia is a recessive disorder caused by the presence of two recessive alleles "s", so genotype is "ss". This disorder is characterized by sickle hemoglobin. In an area with malaria, heterozygous individuals "Ss" (with one dominant allele and one recessive allele) have an advantage. These individuals will have both normal and sickle hemoglobin. But pathogen that causes malaria affect only normal hemoglobin, so heterozygous individuals will have half of the hemoglobin resistant to the pathogen and those individuals are resistant to malaria.</span>
Stabilizing selection favors heterozygotes Ss, disruptive selection favors dominant (SS) and recessive (ss) homozygotes, while directional selection favors dominant (SS) or recessive (ss) homozygote. Since in this example, people with genotype Ss (heterozygotes) are in advantage, then this is an example of stabilizing selection.
The question is incomplete. The complete question is as follows:
Functions of astrocytes include all of the following, except
A) performing repairs in damaged neural tissue.
B) guiding neuron development.
C) functioning in action potential transmission.
D) maintaining the blood-brain barrier.
E) creating a three-dimensional framework for the CNS.
Answer:
Functioning in action potential transmission.
Explanation:
Astrocytes may be defined as the glial type star shaped cells present in the central nervous system. They envelope the synapse and can function with millions of neuron at a time.
Astrocytes are involved in the structural support in the brain and can repair the damaged and wear nerves tissue. Their main function is acting as blood brain barrier. The action potential transmission is mainly done by neurons and not by the astrocytes cells.
Thus, the correct answer is option (c).