Chp. 8 slides 1-26

Question 1

What is genetics?

Answer 1

The science of heredity

Question 2

What controls gene expression?

Answer 2

Operons

Question 3

What are three things altering genes do?

Answer 3

• Cause disease
• Prevent disease treatment
• Manipulated for human benefit

Question 4

The study of genes and how they carry information is called _____

Answer 4

Genetics

Question 5

Structures containing DNA that physically carry hereditary information is called _______

Answer 5

Chromosomes

Question 6

Segments of DNA that encode functional products, usually proteins, is known as ______

Answer 6

Genes

Question 7

All the genetic information in a cell is called a ______

Answer 7

Genome

Question 8

What is the central dogma in Biology?

Answer 8

• Genetic information goes from DNA to RNA to proteins.
• DNA to RNA through transcription
• RNA to proteins through translation

Question 9

The genome of cells are from ___ whereas the genome of viruses are from ___ or ___

Answer 9

• DNA
• DNA or RNA

Question 10

What are chromosomes made up of?

Answer 10

DNA complexed with protein

Question 11

Which chromosomes are a single circular loop?

Which chromosomes are multiple and linear?

Answer 11

• Bacterial chromosomes
• Eukaryotic chromosomes

Question 12

What are the 3 categories of genes and their functions?

Answer 12

• Structural genes: code for proteins
• Genes that code for RNA
• Regulatory genes: control gene expression

Question 13

What is the difference between genotypes and phenotypes?

Answer 13

• Genotype: consists of the genetic makeup
• Phenotype: consists of observable physical traits

Question 14

Rank these genomes from least genes to most genes:

E. Coli, Human cell, Smallest virus

Answer 14

• Smallest virus: 4-5 genes
• E. coli: 4288 genes
• Human cell 31,000+ genes

Question 15

The basic unit of a DNA structure is a ________

Answer 15

Nucleotide

Question 16

What are introns and exons?

Answer 16

Exons: coding regions that code for protein

Introns: non coding regions that do not code for any protein

Question 17

What are the 3 parts of a nucleotide?

Answer 17

• 5 carbon sugar
• Phosphate group
• Nitrogenous base (AGCT)

Question 18

How are nucleotides covalently bonded?

Answer 18

Each sugar is attached to two phosphates in a 5’ to 3’ direction

Question 19

What does it mean when a nucleotide is bonded in a 5’ to 3’ direction?

Answer 19

The phosphate is known as the 5’ and it attaches to the hydroxyl group which is 3’. They ALWAYS attach to each other.

Question 20

When DNA is wrapped around histones, it is known as a _______

Answer 20

Nucleosome

Question 21

Define supercoiling

Answer 21

When DNA takes a nucleosome and turns it into a coil

Question 22

Why is it harder to pull apart a C-G bond than a A-T bond?

Answer 22

C-G has 3 hydrogen bonds whereas A-T has only 2 hydrogen bonds

Question 23

What are two examples of the significance of DNA structure?

Answer 23

• Maintenance of code during reproduction: constancy of base pairing guarantees that the code will be retained
• Providing variety: order of bases responsible for unique qualities of each organism

Question 24

What is the genetic code?

Answer 24

The rules that determine how a nucleotide sequence is converted to an amino acid sequence of a protein

Question 25

The repeating sequences of noncoding DNA are known as _______

Answer 25

Short tandem repeats (STRs)

Question 26

The flow of genetic information from one generation to the next is known as _______

Answer 26

Vertical gene transfer (goes from parent cell to daughter cell)

Question 27

How does horizontal gene transfer work?

Answer 27

It happens in the same generation through conjugation. The donor cell makes a copy of its DNA then attaches to its recipient cell

Question 28

What does the DNA "backbone" consist of? How are the two strands of nucleotides held together?

Answer 28

- Deoxyribose-phosphate - The hydrogen bonds between A-T and C-G

Question 29

True or False: Less than 2% of our DNA are coding DNA

Answer 29

TRUE 98% of our DNA are considered "non coding"

Question 30

What is the purpose of topoisomerase and gyrase?

Answer 30

To relax the DNA strands

Question 31

What is the purpose of helicase?

Answer 31

To separate the DNA strands

Question 32

What is the purpose of primase?

Answer 32

To put RNA primer

Question 33

What are okazaki fragments?

Answer 33

Short DNA fragments formed on the lagging strand during DNA replication

Question 34

Describe the process of DNA replication pt. 1

Answer 34

- One strand serves as the template for the production of a second strand - Topoisomerase and gyrase relax the strands - Helicase will open the DNA by breaking the hydrogen bonds (aka unzipping)

Question 35

Describe the process of DNA replication pt. 2

Answer 35

- Primase will add RNA primer (18-25 single stranded nucleotides that will find complementary bases and bind to it) to the strands - DNA polymerase III will add DNA nucleotides to the new DNA being formed - DNA polymerase I comes and removes RNA primer and replaces it with DNA nucleotides - Ligase attaches DNA fragments together

Question 36

What does the overall replication process achieve?

Answer 36

The replication occurs on both strands simultaneously - Creates complementary strands and is a semiconservative replication process (end up with one parent and one daughter strand)

Question 37

Which is the leading strand and which is the lagging strand?

Answer 37

Bottom: leading Upper: lagging

Question 38

True or False: Viruses cannot go from RNA to DNA

Answer 38

FALSE Since it is not a living organism, viruses have the ability to go from DNA to RNA AND RNA to DNA