Answer: For three traits inherited in a dominant/recessive pattern, the probability of an offspring in a trihybrid cross between parents heterozygous for all three traits to be recessive at exactly two of the three loci is 23/64.
Explanation: Let A, B and C represent the dominant alleles and a, b and c represent the recessive alleles. The genotype of each of the parent will be AaBbCc since it has been said to be heterozygous for all the three traits. There are eight (8) possible different types of gametes from each of the genotype. This can be calculated using 2^n where n is the number of heterozygous loci.
The number of heterozygous loci in the genotype AaBbCc is three (3). 2^3 = 8. The gametes are;
ABC
ABc
AbC
Abc
aBC
aBc
abC and
abc.
Therefore, sixty-four possible offsprings are expected from the cross AaBbCc x AaBbCc.
Out of these offsprings, twenty-three (23) are expected to be heterozygous at two loci as boldly shown in the attached image.
Of the following given choices;
A. glacial erratics B. U-shaped valleys C. unusually shaped rocks D. mudslides.
The answer is; C.
The wind carries soil particles is it blows. These soil particle hit on rocks in their path and over time gradually erode the rocks. An example of this type of erosion is the aeolian process. Usually the bottom o the rock is eroded more than the top. This is because the bottom is hit by larger soil particles that are heavier to carry by the wind. An example of rock formed in this process is attached in the picture below.
During telophase of Mitosis nuclear membranes of two separated nuclei are formed around each set of chromosomes.
<u>Explanation</u>:
Mitosis is the process of cell division part of the cell cycle. Mitosis is classified into four phases which are prophase, metaphase, anaphase and telophase. In prophase the nucleolus disappears, chromosomes start to contents and the mitotic spindle starts to appear and bind to the kinetochore of centromere of the chromosomes. In metaphase nuclear envelope breaks down and the chromosomes becomes fully condensed and organized on the metaphase plate in the middle of the nucleus, during anaphase chromosomes are pulled back to their centromeres with the help of spindle fibers and during telophase the chromosomes starts to decondense, the nucleous reappears and nuclear membrane reforms and spindle starts to disappear.
