Question

Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA?
A) 5'-purine-pyrimidine-purine-pyrimidine-3' with 3'-purine-pyrimidine-purine-pyrimidine-5'
B) 5'-AGCT-3' with 5'-TCGA-3'
C) 5'-GCGC-3' with 5'-TATA-3'
D) 5'-ATGC-3' with 5'-GCAT-3'
E) All of these pairs are correct.

Answer 1

Answer:

D) 5'-ATGC-3' with 5'-GCAT-3'

Explanation:

In a double helix DNA, adenine always pairs with thymine and cytosine pairs with guanine. Also, the two strands of a double helix DNA are antiparallel, that is, the 5' end of one strand lies opposite to the 3' end of another strand.

Therefore, a DNA strand with base sequence 5'-ATGC-3' would have a complementary strand 5'-GCAT-3'.

Double stranded DNA: 5'-ATGC-3'                                          

                                      3' TACG 5'

Answer 2

The study of DNA is called is genetics. In a gene pair, there are two genes out of which one is recessive and the other is dominant.

The correct answer to the question is option D that is 5'-ATGC-3' with 5'-GCAT-3'

What is a double helix structure?

• In molecular biology, the term double helix refers to the structure formed by double-stranded molecules of nucleic acids such as DNA.
• The double-helical structure of a nucleic acid complex arises as a consequence of its secondary structure and is a fundamental component in determining its tertiary structure

In a double helix DNA, adenine always pairs with thymine, and cytosine pairs with guanine. Also, the two strands of a double helix DNA are antiparallel, that is, the 5' end of one strand lies opposite to the 3' end of another strand. Therefore, a DNA strand with base sequence 5'-ATGC-3' would have a complementary strand 5'-GCAT-3'.

Double-stranded DNA:

5'-ATGC-3'                                          

3' TACG 5'

Hence, the correct answer is option D.

For more information about the question, refer to the link:-

https://brainly.com/question/15209553