Answer:
I think it's B but I'm not sure
Spine or Vertebral column is composed of a series of 31 bones known as vertebrae.Spine or Vertebral column is composed of a series of 31 bones known as vertebrae. Curvature of the spine serve the body by giving additional springiness and flexibility to the spine by absorbing the shock Curvature of the spine serve the body by giving additional springiness and flexibility to the spine by absorbing the shock.
Answer:
I, II, III
Explanation:
A threshold stimulus is a stimulus that is capable to produce a response in excitable tissues such as neurons and muscle fibers. At threshold potential, the outward movement of K+ and inward movement of Na+ become equal to each other. When the potential exceeds the threshold potential, more and more Na+ enter the cell to depolarize it and to allow the opening of Na+ channels. Therefore, to fire an action potential, the threshold must be exceeded.
Conduction of action potential is all or none phenomenon which means that either it occurs or it does not occur. As an impulse is passed by each successive part of an exon, it enters the refractory period during which there is no conduction of nerve impulse. It ensures the one-way conduction of impulse from the cell body to the axon terminal only.
Answer:
True
Explanation:
The linkage relation of two genes can be determined on the basis of calculating recombination frequency.
If the recombination frequency value is greater than 50% then the genes are not linked and if the value is less than 50% then the genes are linked.
In the given question, the crossover gametes formed will be Ab = 100
and aB= 106.
Therefore,
Since the recombinant frequency value is larger than 50% therefore the genes do not show linkage.
Thus, True is the correct answer.
I) Locus- the chromosomal site where a specific gene is located. A locus is a fixed position on a chromosome, like the position of a gene or a marker. Each chromosome carries ,many genes; human's estimated haploid (n) protein coding genes are about 20,000, on the 23 different chromosomes.
ii) Interference; the observed double crossover frequency differs from the expected double crossover frequency. Cross over interference is used to refer to the non-random placement of crossovers with respect to each other during meiosis. It results in widely spaced crossovers along chromosomes. Interference may exert its effect across whole chromosomes. As chromosomes in many eukaryotes are large, interference must be able to act over megabase lengths of DNA.
iii) Linkage- the tendency for genes located in close proximity on the same chromosome to be inherited together. Normally when two genes are close together on the same chromosome, they do not assort independently and are said to be linked. Whereas genes located on different chromosomes assort independently and have a recombination frequency of 50%, linked genes have a recombination frequency that is less than 50%.
iv) Recombination- the process by which a new pattern of alleles on a chromosome is generated. Genetic recombination is the production of offspring with combinations f traits that differ from those found in either parent. During meiosis in eukaryotes, genetic recombination involves the pairing of homologous chromosomes. This may be followed by information transfer between the chromosomes.