Answer:
B. As the distance between loci increases, some multiple crossovers go undetected such that the relationship between recombination frequency and map distance ceases to be linear.
Explanation:
When calculating recombination frequencies, and hence, map distances, we might notice that these distances are not completely additive. They might vary. <em>For example, let us say that we have three genes, A, B, and C, in that order. </em>We calculated that the <em>distance between A and B equals 5.9</em> MU and that <em>B and C are 19.5 MU apart.</em> According to this, we might say that the <em>total distance between A and C is 25.4 MU (5.9 + 19.5). </em>However, after a<em> two-point calculation between A and C, the value equals 23.7 MU. </em>
The recombination frequency between these two genes located in the extremes and far apart underestimate the actual genetic distances between them because there might occur other crossing-overs that were not detected. This is <em>when calculating the distance between A and C, we probably will not detect the occurrence of a double recombinant between them, and hence, we might sub-estimate the real distance.</em>
The relationship between the actual map distance (number of crossing overs) and the recombination frequency between two loci, is not lineal. The farther apart are the two genes, the worse is the distance estimation.
<span>The oldest known vascular plants in the northern hemisphere are Devonian
This is true</span>
Answer:
b. The herbicide-resistance gene is cloned into the T-DNA region of the Ti-plasmid.
Explanation:
Ti-plasmid has the ability to introduce part of its DNA (t-DNA) into the genome of host plants. This is very important for the relationship of genetic manipulation in maize plants, with the aim of inducing a gene that promotes herbicide resistance. In addition, T-DNA has many genes that code for the production of plant growth phytohormones, which is extremely important for the cloning process to work. In this case, we can assume that the correct answer for yours is the letter B.
Answer:
The answer is Plasmolysis
