Genetics

Question 1

Nucleotides consist of three things

Answer 1

Nitrogenous Base, Sugar, Phosphate

Question 2

Bases of DNA

Answer 2

Adenine, Thymine, Cytosine, Guanine

Question 3

Bases of RNA

Answer 3

Adenine, Uracil, Cytosine, Guanine

Question 4

Function of DNA

Answer 4

Contains genes

Question 5

How is DNA different from RNA?

Answer 5

DNA is double stranded with deoxyribose sugar and the base Thymine instead of Uracil

Question 6

Function of mRNA

Answer 6

Encode amino acid sequence

Question 7

Start and Stop Codons

Answer 7

AUG (Methionine)

UAA, UGA, UAG

Question 8

Function of tRNA

Answer 8

Delivers amino acids to ribosome. Contains anticodon

Question 9

Sites of the ribosome

Answer 9

E P and A sites, in that order from left to right

Question 10

Function of Helicase

Answer 10

Unwinds DNA double helix

Question 11

Function of Single-Stranded Binding Proteins

Answer 11

Keep DNA Helix separated during replication

Question 12

Function of topoisomerases

Answer 12

Prevent knots from forming due to DNA unwinding by breaking and rejoining the double helix

Question 13

Function of DNA Polymerase

Answer 13

Synthesize new dna in 5 to 3 direction. Needs a primer. Exhibits proofreading ability

Question 14

Function of primase

Answer 14

Creates RNA primers

Question 15

Function of ligase

Answer 15

Joins okazaki fragments

Question 16

Function of telomerase

Answer 16

Attaches to end of template strand and adds DNA nucleotides so telomeres do not shorten

Question 17

Differences between eukaryotic and bacterial chromosomes

Answer 17

Eukaryotic chromosomes are linear. Some DNA is lost from the ends during replication

Question 18

Transcription is performed by what enzymes?

Answer 18

RNA polymerases

Question 19

Transcription: Initiation

Answer 19

TATA box of DNA is promoter. RNA polymerase binds to DNA helix and unwinds it

Question 20

Transcription: Elongation

Answer 20

RNA polymerase assembles RNA nucleotides in 5 to 3 direction.

Question 21

Transcription: Termination

Answer 21

RNA poly comes to terminating sequence (AAAAAA tail)

Question 22

The template strand of DNA has the _____ sequence of bases as the mRNA

Answer 22

Opposite

Question 23

Does RNA polymerase need a primer?

Answer 23

No. DNA polymerase does however

Question 24

mRNA processing

Answer 24

5’ methylated guanine cap, Poly-A tail, splicing (introns are excised and exons are joined together)

Question 25

Translation: Initiation

Answer 25

Ribosome attaches to mRNA. tRNA brings methionine

Question 26

Translation: Elongation

Answer 26

tRNA's bring more amino acids. Amino Acids enter at A site, then go through P site and exit at E site

Question 27

Translocation

Answer 27

Movement of amino acid from A to P site

Question 28

Translation: Termination

Answer 28

Stop codon reached. Ribosome lets mRNA go.

Question 29

What are point mutations?

Answer 29

Single nucleotide errors

Question 30

Types of point mutations

Answer 30

Insertions, Deletions, Substitution

Question 31

What is a frameshift

Answer 31

When a point mutation changes the reading frame of the DNA

Question 32

Nonsense mutation

Answer 32

Premature STOP codon

Question 33

Silent Mutation

Answer 33

Base is changed, but same amino acid is still encoded

Question 34

Missense mutation

Answer 34

Single nucleotide change that results in a changed amino acid

Question 35

What is binary fission?

Answer 35

Asexual reproduction used by bacteria. No genetic variation.

Question 36

What is a plasmid?

Answer 36

Circular piece of DNA

Question 37

What are episomes?

Answer 37

Plasmids that can be found in bacterial chromosomes

Question 38

What is conjugation

Answer 38

Transfer of bacterial DNA through sex pillus

Question 39

What is transduction?

Answer 39

Transfer of bacterial DNA through viruses

Question 40

What is transformation?

Answer 40

DNA from surroundings is integrated by bacteria

Question 41

What kind of operon is the Lac Operon?

Answer 41

Negative Inducible

Question 42

What happens when lactose is ingested?

Answer 42

Lactose becomes allolactose and separates the repressor from the operator, allowing for translation

Question 43

What happens when there are high levels of glucose in the Lac Operon?

Answer 43

No cAMP is made and no transcription takes place

Question 44

What happens when there are high levels of trp?

Answer 44

Tryptophan binds to repressor, allowing it to bind to operator and stop transcription.

Question 45

What happens when there are low levels of tryptophan?

Answer 45

Repressor can't bind to operator, and trp operon makes more tryptophan

Question 46

How does methylation affect transcription?

Answer 46

Decreases it

Question 47

How does acetylation affect transcription?

Answer 47

Increases it

Question 48

Histones

Answer 48

Proteins that DNA coils around

Question 49

Nucleosome

Answer 49

DNA-histone complex

Question 50

Chromatin

Answer 50

DNA mixed with proteins

Question 51

Euchromatin

Answer 51

Loosely packed chromatin

Question 52

Heterochromatin

Answer 52

Tightly packed chromatin

Question 53

What is a testcross?

Answer 53

Test individual with homozygous recessive individual to determine genotype

Question 54

Law of Segregation

Answer 54

Alleles separate during gamete formation

Question 55

Law of Independent Assortment

Answer 55

The inheritance of one set of alleles does not affect the inheritance of another set

Question 56

What is complete dominance?

Answer 56

One phenotype is completely dominant over another

Question 57

What is codominance?

Answer 57

Both phenotypes are equally expressed (roan cow)

Question 58

What is incomplete dominance?

Answer 58

Phenotype is a blend of both genotypes

Question 59

What is pleiotropy?

Answer 59

When one gene has multiple phenotypes

Question 60

What is epistasis?

Answer 60

When one gene masks the effect of another

Question 61

Polygenic inheritance

Answer 61

When multiple genes contribute to a single phenotype

Question 62

Nondisjunction

Answer 62

Chromosomes fail to separate during meiosis or mitosis

Question 63

Linked genes

Answer 63

Genes on the same chromosome

Question 64

Sex-linked inheritance

Answer 64

Genes located on the X chromosome. (Can be Y chromosomes as well)

Question 65

X-inactivation

Answer 65

X chromosomes inactivated by Barr bodies to regulate protein production

Question 66

What is aneuploidy?

Answer 66

Altered number of chromosomes due to nondisjunction

Question 67

What is down's syndrome?

Answer 67

Three chromosome 21's

Question 68

What is turner's syndrome?

Answer 68

Single X

Question 69

Chromosomal mutations

Answer 69

Duplications, Inversions, Translocations (segment of chromosome moves to another chromosome)

Question 70

Telomere Replication

Answer 70

Telomerase ensures that telomeres do not shorten during consecutive replication events

Question 71

Euchromatin

Answer 71

Chromatin that is loosely coiled and easily accessed by transcriptional factors

Question 72

Heterochromatin

Answer 72

Chromatin that is tightly coiled and not able to be accessed by transcriptional factors

Question 73

Transposons

Answer 73

Sequences of DNA that can be moved along the double helix

Question 74

Acetylation

Answer 74

Loosening of DNA wrapping around histones. Leads to increased transcription

Question 75

Methylation

Answer 75

Tightening of DNA wrapping around histones. Leads to decreased transcription

Question 76

Northern Blot

Answer 76

Used to detect specific RNA sequences in an RNA mixture