DNA Structure

Question 1

About _____% of the human body’s DNA is in the _____.

Answer 1

1. 99

2. nucleus

Question 2

99% of DNA is termed _____ DNA.

Answer 2

nuclear

Question 3

_____ DNA is 1% of the human body’s DNA.

Answer 3

1. Mitochondrial

Question 4

The basic structure of DNA is a set of _____ (#) nucleic _____.

Answer 4

1. 4

2. acids

Question 5

Nucleic acids are _____-containing compounds made from the individual _____ acids derived from the _____ we eat.

Answer 5

1. nitrogen
2. amino
3. proteins

Question 6

The basic structure elements of DNA are called _____.

Answer 6

bases

Question 7

List the four bases of DNA:

Answer 7

1. Adenine
2. Cytosine
3. Guanine
4. Thymine

Question 8

Thymine and cytosine are _____-ring(ed) structures known as _____.

Answer 8

1. single

2. pyramidines

Question 9

Adenine and guanine are _____-ring(ed) structures known as _____.

Answer 9

1. double

2. purines

Question 10

List the two purines:

Answer 10

1. adenine

2. guanine

Question 11

List the two pyramidines:

Answer 11

1. thymine

2. cytosine

Question 12

Purines are _____-ring(ed).

Answer 12

double

Question 13

Pyramidines are _____-ring(ed).

Answer 13

single

Question 14

True or false: all four bases are present in any type of DNA, whether from humans and other mammals, plants, bacteria, or viruses.

Answer 14

True

Question 15

Each base becomes a _____ when a _____-sided sugar (known as a _____ sugar) is attached to it.

Answer 15

1. nucleoside
2. five
3. deoxyribose

Question 16

Each _____ becomes a complete nucleotide when _____ groups are attached.

Answer 16

1. nucleoside

2. phosphate

Question 17

The _____ is the final form of a base that is placed into the DNA strand.

Answer 17

nucleotide

Question 18

Nucleotides within each strand are held in position by the linked _____ groups, which act like the string holding beads together to form a necklace.

Answer 18

phosphate

Question 19

_____ _____ are the complementary bases in the two opposite strands of DNA.

Answer 19

1. Base

2. pairs

Question 20

These DNA strands must remain perfectly _____ to each other, and the pairings of the _____ make this happen.

Answer 20

1. parallel

2. nucleotides

Question 21

A _____ with a single-ring structure always pairs up with a _____ that has a double-ring structure to maintain the proper distance down the _____ length of DNA.

Answer 21

1. pyramidine
2. purine
3. total

Question 22

A purine _____ pairs with a pyramidine, and are _____ specific bases forming _____ pairs.

Answer 22

1. always
2. always
3. complementary

Question 23

What always pairs with adenine?

Answer 23

thymine

Question 24

What always pairs with cytosine?

Answer 24

guanine

Question 25

What always pairs with thymine?

Answer 25

adenine

Question 26

What always pairs with guanine?

Answer 26

cytosine

Question 27

Within a base pair, the _____ bonds form between the two nucleotides.

Answer 27

hydrogen

Question 28

Adenine and thymine each have a site for _____ (#) hydrogen bonds to form.

Answer 28

two

Question 29

Cytosine and guanine each have _____ (#) sites for hydrogen bonds to form.

Answer 29

three

Question 30

Although purines must always pair with pyramidines, they can pair only with the base that can form the _____ number of _____ bonds.

Answer 30

1. same | 2. hydrogen

Question 31

Which bases have two hydrogen bonds?

Answer 31

adenine and thymine

Question 32

Which bases have three hydrogen bonds?

Answer 32

cytosine and guanine

Question 33

DNA in humans and other mammals is a linear, _____-stranded (_____DNA) structure with the nucleotides of each strand connected together by the _____ groups as the backbone of the strand.

Answer 33

1. double 2. ds 3. phosphate

Question 34

The dsDNA are held together _____ by _____ bonds.

Answer 34

1. loosely | 2. hydrogen

Question 35

The long steel rails of the railroad track (DNA structure) are the _____ backbones, and the _____ of the nucleotides are each half of the individual railroad ties.

Answer 35

1. phosphate | 2. bases

Question 36

Most of the time, the two parallel strands of DNA are twisted into a loose _____ shape.

Answer 36

helical

Question 37

The DNA supercoils _____ into the chromosome shape only when a cell undergoes _____.

Answer 37

1. tightly | 2. mitosis

Question 38

When can DNA be seen under a standard microscope?

Answer 38

When a cell undergoes mitosis.

Question 39

There is much more DNA in each nucleus than is needed for the _____ (#) to _____ (#) genes.

Answer 39

1. 20,000 | 2. 25,000

Question 40

The gene part of the DNA is only about _____% of all the total DNA in each cell's nucleus.

Answer 40

5