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Worksheets

DNA Molecule

Total questions: 25

Worksheet time: 25mins

Name
Class
Date
1.

What are the basic structural units of a DNA molecule?

a)

glucose molecules

b)

amino acids

c)

lipids

d)

nucleotides

2.

Which scientists developed the double helix model of the DNA molecule?

a)

Watson and Crick

b)

Hardy and Weinberg

c)

Darwin and Lamarck

d)

Weismann and Miller

3.

Watson and Crick described the DNA molecule as a

a)

straight chain

b)

single strand

c)

double helix

d)

branching chain

4.

Match the letter to the part.

5.

A polymer commonly found in the nucleus of cells is

a)

ATP

b)

hemoglobin

c)

cellulose

d)

DNA

6.

Which molecule has the shape of a double-stranded helix?

a)

NANA

b)

DNA

c)

ADP

d)

ATP

7.

The individuality of an organism is determined by the

a)

sequence of nitrogenous bases in deoxyribonucleic acid

b)

number of amino acids in a cell

c)

position of the ribosomes on the endoplasmic reticulum

d)

number of nitrogenous bases in a codon

8.

Which of the following nucleic acids contains thymine?

a)

DNA, only

b)

Messenger RNA, only

c)

Transfer RNA, only

d)

DNA, messenger RNA, and transfer RNA

9.

DNA is a polymer consisting of repeating units known as

a)

dipeptides

b)

nucleotides

c)

amino acids

d)

organic salts

10.

The diagram below represents a portion of a DNA molecule.

a)

The letter X represents two nitrogenous bases that are identical and joined by hydrogen bonds

b)

The letter X represents two nitrogenous bases that are complementary and joined by hydrogen bonds

c)

The letter X represents two nitrogenous bases that are identical and joined by ionic bonds

d)

The letter X represents two nitrogenous bases that are complementary and joined by ionic bonds

11.

The DNA molecule has a ladder-type structural organization. Each rung of this ladder represents

a)

alternating phosphate and glucose molecules

b)

a pair of nitrogenous bases

c)

ribose molecules

d)

a random organization of proteins and lipids

12.

The nitrogen bases found in DNA are represented by the letters

a)

A, U, G, and C

b)

A, T, G, and C

c)

T, A, P, and C

d)

T, U, G, and C

13.

The weakest bonds in a double-stranded molecule of deoxyribonucleic acid exist between the

a)

deoxyribose sugars

b)

phosphate groups

c)

nitrogenous bases

d)

5-carbon sugars

14.

The diagram below represents the building block of a large molecule known as a

a)

protein

b)

fatty acid

c)

carbohydrate

d)

nucleic acid

15.

All nucleotides of DNA and RNA contain a

a)

uracil base

b)

thymine base

c)

ribose sugar

d)

phosphate group

16.

Which of the following best describes a DNA molecule?

a)

double helix

b)

contains ribose

c)

made of amino acids

d)

contains Uracil

17.

Which of the following units are repeatedly joined together to form a strand of DNA? (This is the MONOMER of DNA.) 

a)

amino acids

b)

nucleotides

c)

fatty acids

d)

polysaccharides

18.

Why is DNA important?

a)

it is very small and very complicated

b)

it's in everything

c)

it serves as the blueprint for traits of all living things

d)

because we eat it every day for energy

19.

Which 2 molecules forms the sides (backbone) of the DNA ladder?

a)

deoxyribose and adenine

b)

deoxyribose and a hydrogen bond

c)

sugar and the nucleus

d)

deoxyribose (sugar) and phosphate

20.

Which shows the correct complementary base pairing for DNA?

a)

C-A, T-G

b)

A-G, C-T

c)

C-G, U-A

d)

T-A, G-C

21.

In a molecule of double-stranded DNA, the amount of Adenine present is always equal to the amount of

a)

cytosine

b)

guanine

c)

thymine

d)

uracil

22.

What is the primary function of DNA in cells?

a)

To store genetic information

b)

To provide energy for cellular processes

c)

To catalyze biochemical reactions

d)

To transport oxygen

23.

Which component of the DNA molecule is responsible for its negative charge?

a)

Deoxyribose sugar

b)

Phosphate group

c)

Nitrogenous base

d)

Hydrogen bond

24.

In a DNA double helix, the two strands are held together by

a)

Covalent bonds

b)

Ionic bonds

c)

Hydrogen bonds

d)

Metallic bonds

25.

Which of the following best describes the process of DNA replication?

a)

DNA is transcribed into RNA

b)

DNA is duplicated to produce two identical copies

c)

DNA is translated into proteins

d)

DNA is broken down into nucleotides