Heredity and DNA

Question 1

Define

Heredity

Answer 1

Passing of phenotypes from one generation to the next

Question 2

Define

Phenotype

Answer 2

Physical, heritable traits

Question 3

What questions needed to be answered to understand inheritance?

Answer 3

Is there a pattern to how traits are inherited?
What is physically being inherited?
How does the inherited material lead to an individual’s phenotype?

Question 4

Describe the work of

Gregor Mendel

Answer 4

Scientist that used pea plants to test how traits were inherited;
Found that phenotypes were passed in discrete units

Question 5

Define

Genes

Answer 5

Discrete units of inheritance;
Stretches of DNA that code for specific proteins

Question 6

Describe the work of

Watson & Crick

Answer 6

Scientists that studied DNA and discovered its structure and how it replicated

Question 7

Define

Chromosome

Answer 7

Physical structures made of DNA and protein in the nucleus of cells
Copied and passed from parent cell to each new cell during cell division

Question 8

Define the

Central Dogma

Answer 8

A description of the flow of genetic information, from DNA to RNA to protein

Question 9

Define

Genome

Answer 9

The “instruction book” of genes that makes up an organism

Question 10

Define

Nucleotide

Answer 10

Monomer of nucleotides

Question 11

List the

Parts of a nucleotide

Answer 11

Phosphate group
Five-carbon sugar (“pentose”)
Nitrogenous base

Question 12

Define

Deoxyribose

Answer 12

The pentose / five-carbon sugar used in DNA

Question 13

What are the nitrogenous bases found in DNA?

Answer 13

Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)

Question 14

How do nucleotides join together to form a strand of nucleic acid?

Answer 14

Covalent bonds form between the phosphate of one nucleotide and the five-carbon sugar (pentose) of the next nucleotide
Nitrogenous bases stick off to the side of the strand

Question 15

Define the

Double helix

Answer 15

A common description of the shape of DNA, since it is made of two strands and twists together like a ladder

Question 16

Describe the

“Backbone” of DNA

Answer 16

Alternating sugar and phosphates that make up the sides of the DNA ladder

Question 17

Describe the

“Rungs” of DNA

Rungs = the part of a ladder that go across (that you step on)

Answer 17

Pairs of nitrogenous bases, which are joined together with hydrogen bonds

Question 18

Define

Antiparallel

Answer 18

The two strands of DNA are oriented in opposite directions

Question 19

Define

Complementary Base Pairing

Answer 19

Nitrogenous bases always bind together in a specific way, due to the size and number of hydrogen bonds on each nitrogenous base

Complementary = two things that “complete” each other

Question 20

State

Base Pairing Rules in DNA

Answer 20

Adenine and Thymine always pair
Cytosine and Guanine always pair

Question 21

Describe the relationship between

DNA, Genes, Nucleotides, and Chromosomes

Answer 21

Nucleotides are the individual monomers that string together to make DNA;
A DNA molecule is millions or billions of nucleotides long;
A segment of DNA that codes for a specific protein makes up one gene; and
Each chromosome consists of a DNA molecule (encompassing dozens, hundreds, or thousands of genes) along with proteins that help it coil

Question 22

Define

Chromatin

Answer 22

DNA that is not tightly coiled into chromosomes, which is visible during most of the cell’s life cycle

Question 23

Describe the

Human Genome

Answer 23

About 20,000 genes, organized into two pairs of 23 chromosomes

Question 24

Define

Diploid

Answer 24

Organisms and/or cells that contain two sets of chromosomes

Question 25

Define

Haploid

Answer 25

Organisms and/or cells that contain one set of chromosomes

Question 26

Define

Autosomes

Answer 26

Chromosomes that are found in pairs in diploid organisms;
In humans, chromosomes 1 - 22

Question 27

Define

Sex chromosomes

Answer 27

Chromosomes that are not autosomes, and often determine the sex of individuals;
In humans, X and Y

Question 28

Define

Genetic Females

Answer 28

Humans with two X chromosomes

Question 29

Define

Genetic Males

Answer 29

Humans with an X and Y chromosome

Question 30

Define

Karyotype

Answer 30

A picture of the chromosomes of an organism, arranged from largest to smallest

Question 31

What is being shown in the purple box?

Answer 31

A nucleotide

Question 32

What is being shown in the purple box?

Answer 32

A base pair
Two complementary nucleotides that are joined together

Question 33

What kind of bond is being shown?

Answer 33

Covalent
Form between nucleotides on one strand of DNA

Question 34

What kind of bond would form where the purple arrow indicates?

Answer 34

Hydrogen bond