You perform a test cross of the dihybrid AaBb and score the phenotypes of 1000 progeny. Assuming independent assortment, how man
y of the progeny do you expect to display the dominant phenotype for both the A and B genes?
1 answer:
Answer:
4
Explanation:
<em>The number of progeny expected to display the dominant phenotype for both the A and B genes should be 4.</em>
<u>A test cross usually involves crossing an individual whose zygosity is in doubt with an individual that is recessive for both alleles so as to ascertain the zygosity of the former.</u> Hence, for a test cross involving AaBb:
AaBb x aabb
Progeny:
4 AaBb
4 Aabb
4 aaBb
4 aabb
<em>Therefore, the number of progeny expected to display the dominant phenotype for both the A and B genes is 4.</em>
You might be interested in
<u>Answer</u>: Option D. RNA polymerase.
<u>Explanation</u>:
- Transcription is the process which is used to produce RNA from a DNA template.
- The enzyme involved in the process of transcription is <em>RNA</em> <em>polymerase</em> which is responsible for separating the DNA strands and making an RNA which is complementary to the DNA.
- RNA polymerase joins the nucleotides in the newly formed RNA strands by utilizing the energy released from the cleavage of the additional phosphate bonds that are removed by it.
- The RNA polymerase dissociates from the DNA only after the process of transcription is complete.
Attached is an image with the correct labeling.
