Unit A | Topic 5 | DNA

Question 1

What does DNA stand for?

Answer 1

Deoxyribonucleic acid

Question 2

Definition of:
Chromosomes

Answer 2

Tightly coiled strips of DNA

Question 3

How many chromosomes is each human supposed to have?

Answer 3

46 (23 pairs)

Question 4

What shape does human DNA take?

Answer 4

Double Helix

Question 5

What is DNA made of?

Answer 5

Genes

Question 6

What 3 elements make up a strand of DNA?

Answer 6

• Sugar
• Phosphate
• Nitrogen base

Question 7

What is the name of a group of all 3 nitrogen bases?

Answer 7

Nucleotide

Question 8

What are the names of the 4 kinds of nitrogen bases?

Answer 8

• Adenine
• Thymine
• Cytosine
• Guanine

Question 9

What nitrogen bases are paired together?

Answer 9

1. Adenine & Thymine
2. Cytosine & Guanine

Question 10

What is the name of two conjoined nitrogen bases?

Answer 10

A “rung”

Question 11

What is the name of the two strips of sugar and phosphate that make up the sides of a strip of DNA?

Answer 11

The “Backbone”

Question 12

Where in a cell can chromosomes be found inside the cell?

Answer 12

In the nucleus

Question 13

True or false:
chromosomes are found in all living things

Answer 13

True

Question 14

What is the name of body cells in the human body?

Answer 14

Somatic cells

Question 15

What often happens to somatic cells in the human body

Answer 15

They often need to grow in number or be replaced

Question 16

Definition of:
Mitosis

Answer 16

The process of somatic cells dividing to replace themselves inside an organism

Question 17

Is mitosis Sexual or Asexual?

Answer 17

Asexual

Question 18

What can Mitosis be compared to?
(Hint: has to do with bacteria)

Answer 18

Binary fission

Question 19

What is the process of Mitiosis?

Answer 19

1. Start with a singe cell (contains 2 chromosomes)
2. Chromosomes double in size
3. Chromosomes line up “single file” inside a cell
4. Chromosomes separate along with the cell, creating two cells identical to the parent

Question 20

What is the name of the sex cells found in humans?

Answer 20

Gametes

Question 21

Definition of:
Meiosis

Answer 21

A type of cell division that reduces the concentration of chromosomes in gametes

Question 21

Is meiosis Sexual or Asexual?

Answer 21

Sexual

Question 22

Why is it important that new cells in meiosis only have half the DNA of the parent cell?

Answer 22

Ensures that all cells created via sexual reproduction have the correct amount of cells

Question 23

What is the process of Meiosis?

Answer 23

1. Start with a single cell
   (containing 2 chromosomes)
2. Chromosomes double in size
3. Chromosomes pair up and swap DNA
4. Both chromosomes go to different sides of the cell
5. First cell division, one chromosome in each cell
6. Chromosomes split in half and separate
7. Second cell division, creating 4 unique cells each containing half a chromosome

Question 24

What happens if chromosomes don’t separate during meiosis?

Answer 24

Nondisjunction:
An abnormal amount of chromosomes become present, which can lead to things like disorders

Question 25

Definition of:
Mutation

Answer 25

A change to a strand of DNA, causes the structure to change and individual bases could be mixed up

Question 26

What are some causes of mutations?

Answer 26

• X rays
• Ultraviolet rays
• Cosmic rays
• Chemicals

Question 27

True or false:
All mutations are negative

Answer 27

False:
While many mutations are negative, some do nothing and some are even beneficial

Question 28

How many cell divisions occur in mitosis?

Answer 28

One

Question 29

How many cell divisions occur in meiosis?

Answer 29

Two