Answer:
Sugars and phosphates
Explanation:
DNA is deoxyribonucleic acid.
The backbone is based on a repeated pattern of a sugar group (deoxyribose) and a phosphate group.
The image below shows one straightened-out strand of DNA with a backbone of alternating sugars and phosphates.
A is wrong. There is no ribose in DNA.
B is wrong. The nucleic acids A, C, G, and T join one strand of DNA to the other.
C is wrong. There is no RNA in DNA.
It is true that r-related species have a short life span and an early reproduction cycle. R-related species also known as r-strategist have a short and simple life span. Due to their simple life span, their nutrient exchange rate with the environment is rapid. Unlike K-selected species, they have the ability to reproduce at a young age. They reproduce a large number of off-springs, but many of their off-springs tend to die before attainment of their reproductive age.
Answer:
2% of the progeny will be double crossovers for the trihybrid test cross
Explanation:
By knowing the positions of genes, we can estimate the distances in MU between them per region.
- Genes A and B are 10 map units apart (Region I)
- Genes B and C are 20 map units apart (Region II)
- Genes A and C are 30 map units apart
----A-------10MU--------B-------------20MU-------------C---
Region I Region II
We can estimate the recombination frequencies by dividing each distance by 100.
• recombination frequency of A-B region = 10MU / 100 = 0.10
• recombination frequency of B-C region = 20MU / 100 = 0.20
Now that we know the recombination frequencies in each region, we can calculate the expected double recombinant frequency, EDRF, like this:
EDRF = recombination frequency in region I x recombination frequency in region II.
EDRF = 0.10 x 0.20 = 0.02
2% of the progeny will be double crossovers for the trihybrid test cross
