Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Genetics > Exam 2 > Flashcards

Exam 2 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What is incomplete dominance?

A

Phenotype of heterozygote is intermediate between two homozygotes; given in “doses” so heterozygote yields a pink flower if crossing red and white

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is codominance?

A

Heterozygotes display the phenotype of both homozygotes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What determines blood type in cell?

A

What type of antigen they have on the cell surface or if there is no antigen (O) or both antigens (AB - codominant)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is an antigen?

A

A complex sugar molecule that sits on the outside of blood cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are recessive lethal alleles?

A

Alleles that are lethal can have pleiotropic effects on a second trait

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is pleiotropy?

A

One gene affects many traits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is polygenic?

A

More than one gene influences a single trait; measured on a continuous scale

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is an example of a polygenic trait?

A

Several genes influence anxiety

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are two ways for mutations to produce the same phenotype?

A

Different mutations in one gene may produce the same phenotype or mutations on different genes of the same pathway may produce the same phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

When there’s different mutations in one gene, what will the offspring be?

A

Mutants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

When there’s mutations in separate genes on the same pathway, what will the offspring be?

A

Wild-type phenotypes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is it called when mutations are in a separate gene acting in the same pathway?

A

Complementation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the phenotypic ratio of a complementation on a gene?

A

9:7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the phenotypic ratio of duplicate genes?

A

15:1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are duplicate genes?

A

One normal copy is sufficient to produce the wild-type phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is penetrance?

A

Proportion of individuals with a given genotype that express the phenotype (there or not there)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is expressivity?

A

The EXTENT to which a given phenotype is expressed at the phenotypic level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What blood type cross can produce all 4 types of blood?

A

I^Ai x I^Bi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What experiment did Frederick Griffith do?

A

Compared the effects of smooth virulent strains of streptococcus pneumoniae and rough non-virulent strains of it in mice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does the smooth strain of the bacteria have?

A

A polysaccharide capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What happens when heat-killed smooth strains were injected?

A

Mice live

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What happens when heat-killed smooth strains and rough strains were intermingled and injected? Why?

A

Mice die because DNA can transform rough, non-virulent strain to smooth, virulent phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What experiment did Oswald Avery do?

A

Tested all the chemical components of cells (i.e. lipids, proteins, etc.) for the ability to transform

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What did Alfred Hershey and Martha Chase do?

A

They infected the bacteria with viruses and labeled them with radioactive sulfur (not contained in DNA) and found that there was no sulfur in the progeny phage but when they injected the bacteria with a virus labeled with radioactive phosphorus (not contained in proteins) the progeny phage had radioactive phosphorus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are structural properties of DNA?

A

Ability to store information (i.e. genetic code), ability to be replicated, or ability to mutate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Who discovered the structure of DNA?

A

Watson and Crick

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are purine bases and which ones are they?

A

Bases with 2 rings; guanine and adenine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are pyrimidine bases and which ones are they?

A

Bases with 1 ring; cytosine and thymine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is 1 nucleotide?

A

Base pair + phosphate group + deoxyribose sugar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is Chargaff’s Rule of base composition?

A

Number of pyrimidine nucleotides = number of purine nucleotides, number of C=G and number of T=A, but number of T+A doesn’t always equal number of C+G

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the major groove?

A

Where most of the protein to DNA interactions occur

32
Q

What is semiconservative replication?

A

Each of two original strands of DNA act as templates for new strands

33
Q

What were the Meselson-Stahl experiments?

A

Conservative replication yields one N15 band of DNA and one N14 band of DNA; semiconservative yields hybrids and that which is added; dispersive yields hybrids (different sections are N15 and N14)

34
Q

What was the purpose of the Cairns experiment?

A

Predict there is a replication fork

35
Q

How did the Cairns experiment prove there is a replication fork and that bacterial DNA is circular?

A

It showed two distinct replication forks in the circle because a strand twice as big started to replicate within the circle because it had 2 radioactive strands

36
Q

What does DNA polymerase in general do?

A

Catalyzes the elongation of new strands of DNA during replication

37
Q

What does primase do?

A

Creates the RNA primer that initiates DNA synthesis

38
Q

What does the DNA polymerase III do?

A

Produces okazaki fragments and creates daughter DNA strand

39
Q

What does DNA polymerase I do?

A

Degrades the RNA primer and fills the gaps with DNA

40
Q

What does helicase do?

A

Disrupts the hydrogen bonds that hold the double helix together and unzips the double helix ahead of DNA synthesis

41
Q

What does topoisomerase do?

A

It relaxes the supercoiled DNA by breaking one or both strands of the DNA

42
Q

What is telomerase?

A

Carries a short RNA molecule (telomere) that acts as a template for the addition of nucleotides to the 3’ end of a DNA template

43
Q

When working the Meselson-Stahl experiment what will be the “new” DNA in semiconservative replication?

A

One strand of all bacterial chromosomes

44
Q

Given the following sequence of single-stranded DNA, identify the complementary strand: 5’ - ATCCCGTAGGA - 3’

A

5’ - TCCTACGGGAT - 3’

45
Q

Which scientists provided strong evidence that DNA is the hereditary material in viruses?

A

Alfred Hershey and Martha Chase

46
Q

What does the double helix consist of?

A

Nucleotides held together by phosphodiester bonds (3’ OH to 5’ phosphate) and strands held together at the bases by H bonds

47
Q

What are four differences between DNA and RNA?

A

RNA is single-stranded and DNA is double-stranded making RNA more flexible, RNA has ribose sugar and DNA has deoxyribose sugar, RNA has uracil instead of thymine, and RNA can catalyze biological reactions because it is more like a protein enzyme

48
Q

What is the difference between messenger RNA and functional RNA?

A

Messenger RNA encodes the information necessary to make proteins that serves as an intermediary between DNA and proteins whereas functional RNA doesn’t encode information to make proteins but is the final functional product

49
Q

What is tRNA?

A

Molecules responsible for bringing the correct amino acid to the mRNA during translation

50
Q

What is rRNA?

A

Major components of ribosomes

51
Q

What do ribosomes do?

A

Guide the assembly of the amino acid chain by the mRNAs and tRNAs

52
Q

What are small nuclear RNAs (snRNAs)?

A

Some unite with several subunits to form the spliceosome that removes introns from mRNA

53
Q

What is the central dogma?

A

Genes are in DNA, DNA is transcribed to mRNA, mRNA is translated to protein, protein the therefore the functional product of genes

54
Q

What is RNA considered?

A

The molecular intermediate between DNA and protein

55
Q

How is mRNA copied?

A

In the 5’ to 3’ direction from the template DNA strand so it is identical to the non template strand except the Ts are Us

56
Q

What does RNA polymerase I do?

A

Synthesizes ribosomal RNA

57
Q

What does RNA polymerase II do?

A

Synthesizes messenger RNA

58
Q

What does RNA polymerase III do?

A

Synthesizes transfer RNA and small nuclear RNA

59
Q

What is the difference between transcription in eukaryotes vs. prokaryotes?

A

Genome organization and size is much more complex in eukaryotes because of splicing and each gene has a promoter, transcription and translation are divided between nucleus and cytoplasm in eukaryotes, and genomic DNA in eukaryotes is packaged with proteins into chromatin whereas prokaryotic DNA is more or less naked

60
Q

What is the process of initiation of transcription?

A

The promoter at the 5’ end is attached to a TATA box the is the binding site for the TATA binding protein (TBP). This protein then recruits general transcription factors that are needed to form a pre-initiation complex. The pre-initiation complex then recruits RNA polymerase II to the promoter and positions the enzyme at the start site of transcription.

61
Q

What is the process of elongation?

A

RNA polymerase II is released by phosphorylation of the carboxyl tail domain (CTD) of the polymerase enzyme thus starting elongation.

62
Q

What is the process of pre-mRNA processing?

A

Capping, splicing, cleavage, and polyadenylation; CTD contains binding sites for the protein machinery needed to perform each modification which allows it to be processed right away

63
Q

What is capping?

A

At the 5’ end a cap is added by guanyltransferase or 7-methylguanosine enzyme that protects the RNA from degradation and assists in translation

64
Q

What is cleavage and polyadenylation?

A

At the 3’ end a poly(A) tail of 100-200 “A” residues is added by polyA polymerase once RNA transcript is cleaved 20 bases down from the polyadenylation signal (AAUAAA) that signals the termination of transcription

65
Q

What is splicing?

A

Removal of introns from the RNA by spliceosomes at the 5’ GU, A at branch point, and 3’ AG sequence. snRNPs U1 and U2 bind to the GU sequence and branch point A then other proteins (U4, U5, and U6) are then recruited to form the spliceosome and mRNA is twisted so the GU site is in contact with the A branch point. The 3’ AG is then cleaved from the exon.

66
Q

What can be said about the GU, A, and AG sequences that are at the intron/exon junction?

A

They are 100% conserved

67
Q

What does the spliceosome contain?

A

RNA and proteins

68
Q

What was the Harlequin chromosome experiment?

A

DNA was replicated normally but then thymine was replaced with an analog (BrdU). BrdU doesn’t take up stain like normal thymine so if DNA is semiconservative then one chromosome (parental) would be stained and the other chromosome in the pair wouldn’t be (daughter that BrdU is in). This is what the results were. If it were conservative then there would be chromosome pairs that were stained and chromosome pairs that weren’t.

69
Q

What features of DNA lend itself to replication?

A

Complementary base pairing allows for easy “filling in” of adjacent bases, since it’s only H bonds holding the bases together it’s easy to break them in order to replicate, and phosphodiester bonds connecting nucleotides in DNA are strong enough to preserve the order of the bases

70
Q

What was wrong with Linus Pauling’s triple helix?

A

Chargaff’s rules indicate that bases are present proportionally and having the bases outward complementarity of the two strands isn’t possible and the phosphates would repel each other due to electronegativity and the molecule would be unstable

71
Q

Why are primers necessary for DNA replication?

A

The major DNA polymerase involved in replication is unable to initiate DNA synthesis and requires the 3’ OH group that the primer has to create the next phosphodiester bond

72
Q

Why is DNA continuous on one strand and discontinuous on the other?

A

The polymerase is capable of adding new nucleotides only at the 3’ end of the DNA strand and because the strands are antiparallel, at least two molecules of polymerase must be involved. Since there is a replication fork the leading strand leads continuously “downstream” and the opposite strand must move toward the fork in okazaki fragments because the fork is always opening new single-stranded DNA

73
Q

If the DNA template strand 5’ - ATGCATGC - 3’ were transcribed to RNA the RNA would read…?

A

3’ - UACGUACG - 5’

74
Q

What do the GTFs function as part of the pre-initiation complex?

A

Identify a gene’s promoter, facilitating RNA polymerase II binding

75
Q

What is the role of tRNA?

A

To act as transporters bringing amino acids to the site of protein synthesis

Genetics (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions