DNA, RNA

How many hydrogen bonds do C and G base pairs form? (Write the Hindu-Arabic form)

Answer explanation

Cytosine (C) and Guanine (G) base pairs form three hydrogen bonds between them. This strong bonding contributes to the stability of the DNA structure.

Name the specific sugar used in DNA. Use lower case letters.

Answer explanation

The specific sugar used in DNA is deoxyribose. It is a five-carbon sugar that is essential for the structure of DNA, forming part of the backbone along with phosphate groups.

All the following compose nucleosides EXCEPT

• phosphate groups

• purine base

• deoxyribose sugar

• ribose sugar

• pentose sugar

Name the nucleic acid that is double-stranded. Give the complete name. Use all small lower case letters. Avoid unnecessary characters.

Answer explanation

The nucleic acid that is double-stranded is deoxyribonucleic acid, commonly known as dna. It consists of two strands that form a double helix structure, which is essential for storing genetic information.

The nucleotide bases of nucleic acids are based on purine and pyrimidine rings which contain (one, two) and (one, two) rings; respectively. Choose your answers from the words in parentheses. Separate your answers with a comma and of course a space, like this: methane, ethane).

What type of DNA conformation is shown in this figure (top view)? ____ form

All the following statements describe both the spiral structure of double-stranded DNA and the spiral structure found in certain segments of protein EXCEPT

• they are alpha-helical

• they have covalently linked backbones

• they have hydrogen bonding

• the units are specifically arranged in polymeric chains

• they are repeating spiral structures

In the carbon skeleton of the pentose sugar shown in the figure, what is the attachment point of a base to form a nucleoside?

• C3

• C4

• C2

• C5

• C1

The most common conformation for DNA is the Answer B-DNA form.

Which of the following statements about ribosomes is true?

• They are an integral part of the transcription.

• They are composed of RNA, DNA, and protein.

• They are found both free in the cytoplasm and bound to membranes.

• They are composed of three subunits of unequal size.

• They are bound together so tightly they cannot dissociate under physiologic conditions.