Genetic Change and Traits Lesson Review

Question 1

a change in a DNA sequence that leads to a difference in traits

Answer 1

Genetic Change

Question 2

_____ is a double-stranded molecule organized into structures called chromosomes

Answer 2

DNA

Question 3

DNA is made up of _____ that pair together to form two complementary sides

Answer 3

nucleotides

Question 4

Each side, or strand, of DNA is a chain of building blocks called _____

Answer 4

nucleotides

Question 5

These repeating chemical units, nucleotides, join together to form _____

Answer 5

a DNA molecule

Question 6

One part of a nucleotide is called the _____

Answer 6

base

Question 7

There are four different nucleotides in DNA which are identified by their bases:

Answer 7

adenine (A)
guanine (G)
cytosine (C)
thymine (T)

Question 8

Combinations of DNA base pairs make “genetic words” called _____

Answer 8

genes

Question 9

The amino acid chain forms _____

Answer 9

proteins

Question 10

A specific sequence of three bases on a gene code for a specific amino acid; these sequences are called _____

Answer 10

triplets

Question 11

A change in the base-pair sequence of a gene is called a _____

Answer 11

mutation

Question 12

Most mutations occur when _____

Answer 12

a cell copies its DNA for cell division

Question 13

Examples of mutagens include _____ and _____

Answer 13

UV radiation

the chemicals in cigarette smoke

Question 14

Traits that help organisms survive and reproduce in their current environment are called _____

Answer 14

adaptations

Question 15

An adaptation can be a _____, a _____, or a _____.

Answer 15

structure
function
behavior

Question 16

Adaptions are the result of _____, _____, and _____ in an environment over many generations.

Answer 16

genetic change
inheritance of adaptive traits
survival advantage

Question 17

What do genes code for?

Answer 17

amino acid chains