Answer:
The correct answer will be option- synaptonemal complex.
Explanation:
The tetrad arrangement of the genetic material in an organism is mediated by a highly conserved structure known as the synaptonemal complex. The synaptonemal complex is formed during the prophase I of the meiosis I which attaches the chromatin of the homologous chromosomes.
The synaptonemal complex is a proteinaceous structure which is formed by the two lateral ladders like elements with a central portion composed of the central element. The chromatin gets attached to the lateral elements while the central a portion bridge space between the two ladders thus help in the formation of the tetrad.
Thus, option- synaptonemal complex is the correct answer.
Complete question:
In a separate study, 68 rock pocket mice were collected from four different, widely separated areas of dark lava rock. One collecting site was in Sonora, Mexico. The other three were in Chihuahua, Mexico. Dr. Nachman and colleagues observed no significant differences in the color of the rocks in the four locations sampled. However, the dark-colored mice from the three Chihuahua locations were slightly darker than the dark-colored mice from the Sonora population. The entire Mc1r gene was sequenced in all 68 of the mice collected. The mutations responsible for the dark fur color in the Sonora mice were absent from the three different populations of Chihuahua mice. No Mc1r mutations were associated with dark fur color in the Chihuahua populations. These findings suggest that adaptive dark coloration has occurred at least twice in the rock pocket mouse and that these similar phenotypic changes have different genetic bases.
How does this study support the concept that natural selection is not random?
Answer:
The study supports the concept that natural selection is not random because in different areas with the same or very similar environmental characteristics, the same phenotype was produced by different types of mutations.
Explanation:
All of the sampled animals are inhabiting dark substrate. Probably animals needed to camouflage to survive. Natural selection must have driven them to produce dark color, similar to the substrate color. So animals from the different regions suffered different mutations that drove them to have almost the same dark fur color. The environmental condition is favoring the same phenotype.
The supporting structure of the cell that is also involved in movement is most likely the cytoskeleton.
Plant cells have cell wall but animal cells don't have any cell wall.
The main benefit of crossing over is that it increases genetic diversity.
<h2>
Crossing over and
Genetic Diversity</h2>
Crossing over ensures that the daughter cells produced are genetically more diverse than their parent cells.
The exchange of chromosomal segments makes the chromosomes of the daughter cells to be more sophisticated than that of their parents.
Increased genetic diversity in daughter cells increases their chances of survival as more genes are present in their genomes that could potentially make them more adaptable to the environment.
In summary, crossing over increases genetic diversity and genetic diversity increases the chances of survival in the face of changing environment.
More on genetic diversity can be found here: brainly.com/question/1446827?referrer=searchResults
