Question

part a: multiple choice
circle the correct answer.

1. dna is made of repeating units called:

a. amino acids
b. nucleotides
c. lipids
d. carbohydrates

1. which bases pair together in dna?

a. a—u and c—g
b. a—c and t—g
c. a—t and c—g
d. a—g and t—c

1. a gene is best described as:

a. a strand of rna
b. a section of dna that codes for a protein
c. a group of cells working together
d. a type of carbohydrate

Explanation:

1. DNA is a nucleic acid, built from repeating nucleotide subunits; amino acids form proteins, lipids and carbohydrates are separate macromolecules.
2. In DNA, adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G); uracil (U) is only in RNA.
3. A gene is a specific segment of DNA that contains the instructions to produce a functional protein (or RNA molecule).

Answer:

1. b. Nucleotides
2. c. A-T and C-G
3. b. A section of DNA that codes for a protein