Answer:
Thymine
Explanation:
Adenine is a Purines together with Guanine .
Purines always pair with Pyrimidines ; which are cyosine and Thymine.
This is a complementary base pairing that hold the two strands of DNA bases together by weak hydrogen bonds for flexibility and easily unwind during replication
Purines are larger in size beaxuae they have 2 ring structures while Pyrimidines aee smaller because of one ring structure.
Therefore two purines (Adenine and Guanine can not pair together;
It must be a Purines -Pyrimidines pairs.
Therefore Adenine must pair with Thymine and cyosine with Guanine
In RNA, Thymine are replaced with URACIL as Pyrimidines.
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The correct answers are:
• transcribe RNA that combines with a protein that has a DNA-cleaving function.
• identify viral DNA by complementary base pairing with template DNA.
CRISPR is a DNA sequence found in bacteria (or other prokaryotic cell), derived from DNA fragments from viruses that have previously infected that bacteria. Bacteria use CRISPR to destroy DNA from next similar viruses. So, it is form of antiviral defense in bacteria.
Cas9 is an RNA-guided DNA endonuclease enzyme (DNA-cleaving function) associated with the CRISPR that cleave specific sequences of DNA complementary to the CRISPR sequence.
The first geneticist has identified an obese allele that he or she believes to be recessive. We will define his or her allele as o1 and the normal allele as O1. The obese allele appears to be recessive based on the series of crosses he or she performed.
Cross 1 with possible genotype:
Obese (o1o1) × Normal (O1O1) F1 All normal (O1o1)
Cross 2 with possible genotypes:
F1 normal (Oo1) × F1 normal (O1o1) F2 8 normal (O1O1 and O1o1)
2 obese (o1o1)
Cross 3 with possible genotypes:
Obese (o1o1) × Obese (o1o1) All Obese (o1o1)
A second geneticist also finds an obese mouse in her colony and performs the same types of crosses, which indicate to her that the obese allele is recessive. We will define her obese allele as o2 and the normal allele as O2.
The cross of obese mice between the two different laboratories produced only normal mice. These different alleles are both recessive. However, they are located at different gene loci. Essentially, the obese mice from the different labs have separate obesity genes that are independent of one another.
The likely genotypes of the obese mice are as follows:
Obese mouse 1 (o1o1O2O2) × Obese mouse 2 (O1O1o2o2)
F1 All normal (O1o1O2o2)
The last one, I believe.
This is a male, with three copies of chromosomes 21
Hope it helps :D
