Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Genetics > Exam 2 > Flashcards

Exam 2 Flashcards

(80 cards)

Start Studying
1
Q

How is the influenza virus genome organized?

A

8 ssRNA negative strands (each in nucleoprotein complex) –> has multiple pieces of genome, as opposed to just one genome
enveloped virus –> easily transmitted
each segment encodes a protein

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

Which genes are important for infecting a cell?

A

immediate early genes
early genes
late genes

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

How can new strains of influenza arise?

A

proteins can change, new strand = one of the proteins has changed
coinfection with different influenza viruses = new combinations

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

What two types of infection do herpesviruses have? What regulates these?

A

latent (silent) and lytic
depends on how tightly DNA is wrapped with histones
condensed = latent
loose = lytic

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

What is unusual about the location of herpesviruses in the cell?

A

replicates in the nucleus of the cell (others usually replicate in cytoplasm)

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

Describe the process of infection by retroviruses and gene expression.

A

cell converts RNA from retrovirus into DNA –> inserted into DNA of host cell –> cell produces more retroviruses

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

What is a provirus?

A

virus genome that is integrated into DNA of host cell

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

What kind of mutation can be caused by retrovirus infection?

A

if it inserts in the middle of the gene, it’ll screw it up
if it’s next to another gene that has a strong promoter, it’ll make the gene really strong (?)

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

How are the immediate early and early proteins produced in a coronavirus infection?

A

ORF1b responsible for making proteins

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

What is unusual about the translation of ORF1b?

A

encodes 2 proteins
pseudoknot in mRNA stalls ribosome –> induces slippage
frameshift to new reading frame = new protein

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

How are the late coronavirus proteins produced?

A

encoded by sgRNAs after frameshift

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

How does coronavirus escape the RNAi machinery of the cell?

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

What are the different forms in which viral genomes are found? What are they in the viruses in this section?

A

enveloped (has a membrane) v.s. nonenveloped (no membrane)

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

How would the presence of a membrane on a virus affect its stability in the environment and its mode of exit from the cell?

A

enveloped = more sensitive to environment (like STDs and flu)
non enveloped = more stable

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

What are the three classes of genes that are generally found in viruses (depending on their genome size) and what are their functions?

A

immediate early genes - hijack cell, takes over host metabolism
early - replicate virus
late - make virus structural proteins

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

How does a virus enter a cell?

A

needs to be a receptor (protein on cell that virus recognizes)

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

What does host range mean?

A

types of organisms/cell that a virus can infect
these need to have the right receptor

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

What are the early genes in adenovirus and what is their function?

A

E1A, E1B - activates cell metabolism

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

How does late gene expression produce the variety of viral proteins?

A

mRNAs from major late promoter differentially spliced to produce viral proteins

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

How is the adenovirus genome used to generate vaccines? Why are E1 and E3 deleted in these vaccines?

A

you take some of the virus genes out and insert the gene for what you want
E3 supresses host immune response, makes virus into better vaccine
E1 - extra space to insert genes, also don’t want disease to be infectious

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

Which proteins of adenovirus and papillomavirus bind Rb and p53, and for what purpose?

A

E6, E7 - basically do the same thing as E1 in adenovirus

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

What is the relationship between the structure of a wart and papillomavirus gene expression?

A

gene expression/ which ones are turned on depends on where in the skin they are
cells at base are alive, don’t do much –> start dividing/differentiate = other proteins get made inside virus

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

How do the genomes of prokaryotes and eukaryotes differ?

A

prokaryotes - smaller, simpler, one chromosome
eukaryotes - bigger, more complex, multiple chromosomes

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

interphase

A

cell growth
divided into 3: G1, S, G2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
interphase
nuclear envelope present, chromosomes relaxed
26
Describe the mechanisms of chromosome separation in mitosis
spindle microtubule anchors to kinetochore chromosomes are pulled apart
27
how does meiosis differ from mitosis?
mitosis creates two identical daughter cells from one parent meiosis creates cells that are unique from parent 1st division - homologous chromosomes separate 2nd division - sister chromatids separate
28
what happens in each step of prophase I in meiosis?
leptotene - chromosomes condense zygotene - synaptonemal complex (protein that connects homologous chromosomes - looks like railroad tracks) forms pachytene - crossing over; DNA exchanged btwn non-sister chromatids diplotene - chiasma (point where chromosomes are crossed) visible in bivalent diakinesis - nuclear membrane disintegrates
29
Distinguish the functions of mitosis vs. meiosis
mitosis - cell regeneration, growth, asexual reproduction (only in autosomes) meiosis - production of gametes for sexual reproduction
30
in what ways is diversity in offspring generated through each meiotic division?
homologous chromosomes segregate to different cells; which goes where can vary recombination - pieces get swapped, location can vary
31
contrast gametogenesis in male vs. female mammals
spermatogonium produces 4 sperm (basically sperm divides into 2 equal and then 4 equal sperm) oogonium produces 1 ovum + 1 polar body (only has half DNA; unequal)
32
M phase
nuclear and cell division mitosis and cytokinesis take place
33
G1
cell grows
34
G0
non dividing phase (not every cell goes through)
35
S
DNA replicates
36
G2
cell prepares for mitosis
37
prophase
chromosomes condense chromosome has 2 chromatids mitotic spindle forms
38
prometaphase
nuclear membrane disintegrates spindle microtubules (attached to centrosomes on one side) attach to chromatids
39
metaphase
chromosomes line up on metaphase plate (middle)
40
anaphase
sister chromatids separate and move towards opposite poles
41
telophase
chromosomes arrive at spindle poles nuclear membrane reforms
42
what are 2 errors that can occur in cell division?
microtubule fails to attach to chromosome, chromosome is loose and is lost when nuclear envelope reforms = missing chromosome sister chromatids don't separate = extra chromosome in one cell
43
State Mendel’s first law in your own words
each trait has 2 alleles separate in gamete formation separate in equal proportions
44
monohybrid cross
2 parents, 1 trait
45
dihybrid cross
2 parents, 2 traits (RrYy)
46
monohybrid and dihybrid testcrosses
cross with homozygous recessive (tt) to decide if individual is homozygous or heterozygous
47
State Mendel's second law in your own words. How do you explain these laws, given our knowledge of alleles and chromosomes (remember, Mendel had no knowledge of chromosomes)?
two traits don't affect each other (not always true) i.e. seed color (Y or y) doesn't really affect seed shape (R or r)
48
Describe the role of probability in analyzing genetic data
because we can only have a certain amount of options in what phenotypes are passed down/expressed, we can predict the probability
49
What is the null hypothesis?
no relationship exists btwn the two sets of data (observed v.s. expected data)
50
Of the different modes of sex determination, describe that in: birds
ZZ- ZW system - present in birds, butterflies, some reptiles, amphibians, fish (sex can be determined based off temperature) W is sex-determining females ZW males ZZ (so basically opposite of humans)
51
Of the different modes of sex determination, describe that in: Drosophila, role of doublesex gene
depends on X (number of sex chromosomes) : A (number of all other chromosomes) ratio basically if it has XX (could be XX or XXY or XXXY) = female XO is male (bcus no XX), but sterile (bcus no Y)
52
Of the different modes of sex determination, describe that in: mammals, including humans
Y chromosome determines gender X chromosome is "normal" chromosome (has uses outside of sex) XX = female XY = male
53
How can the Amami spiny rat have two sexes without a Y chromosome?
most mammals have Sry gene --> sox9 --> y chromosome y chromosome not produced if sox9 inhibited (i.e. females) amami don't have Sry but do have 2 enhancers that work together to turn on sox9
54
What causes Turner's and Klinefelter's syndromes?
Turner - XO (not male, but still lacking female hormones, can be treated with estrogen), infertile Klinefelter's - XXY (male, but with female traits, like smaller testes, breasts, lack of facial hair), infertile
55
How do Turner's and Klinefelter's syndromes develop in meiosis?
nondisjunction - chromosomes/chromatids are supposed to separate in meiosis 1 or 2, but don't BE ABLE TO DRAW
56
sex-linked traits
traits that only appear in one sex (usually male)
57
Analyze crosses that involve sex chromosomes: contrast the results when the male vs. the female carries the trait
if trait is on X chromosome, females have another that make up for it, males don't
58
Contrast the structure of the X and Y chromosomes
59
What is the pseudoautosomal region?
homologous gene sequences parts of Y chromosome that have same sequences as X chromosome (and line up with during meiosis)
60
dosage compensation --> why is it important?
this is what regulates how genes are expressed evenly despite different chromosomes (i.e. men are missing an X so how do all those genes get expressed?)
61
how does dosage compensation happen in mammals?
one X chromosome usually shut down Xist gene makes RNA, doesn't encode protein, coats chromosome, facilitates methylation --> shuts down chromosome
62
How does dosage compensation happen in Drosophila?
X linked genes expressed twice as much
63
why do we even have sex differentiation?
meiosis - alleles get mixed up and things get switched around sex depends on which genes are switched on and off
64
incomplete dominance
heterozygous phenotype falls between two homozygous phenotypes phenotype red + phenotype white = phenotype pink
65
codominance
heterozygous phenotype expresses phenotype of both homozygous phenotypes
66
penetrance
percentage of individual organisms having a particular genotype that express the expected phenotype (i.e. 42 people have allele for trait, only 38 express, penetrance = 38/42)
67
expressivity
degree to which trait is expressed (how much gene is expressed)
68
lethal alleles
causes death at early stage of development
69
multiple alleles
more than 2 alleles on same locus
70
gene interaction
activity at one locus affects activity at another
71
epistasis
gene interaction where different genes are dependent on one another E --> F --> G A B if enzyme A is needed to turn E to F, but A is defective, then F won't get made, B has nothing to work with, etc. --> i.e. B is dependent on A
72
what does a skip in generation tell you about trait?
probably recessive since it needs 2 carriers
73
How can a pedigree tell you if a trait is autosomal dominant?
doesn't skip generations only needs one parent to express trait shows up equally in males and females
74
How can a pedigree tell you if a trait is X-linked dominant?
doesn't skip generations females (if hetero) will pass it to 1/2 sons and 1/2 daughters males will pass it to ALL daughters but NO sons
75
How can a pedigree tell you if a trait is Y-linked?
only appears in males all male offspring will be affected
76
How can a pedigree tell you if a trait is X-linked recessive?
more frequent in males males won't pass it to sons but can pass to daughters --> carriers daughters with allele pass to sons who express the trait
77
How can a pedigree tell you if a trait is autosomal recessive?
equally appears in both sexes skips generations (needs 2 parents to be carriers) likely in offspring from parents that are related
78
dizygotic twins
nonidentical 2 separate eggs fertilized by 2 separate sperm --> genetically distinct zygotes (basically no different from normal siblings except they were born at the same time)
79
monozygotic twins
same egg, same sperm --> splits into separate embryos early on share 100% same genes
80
what is the general course of infection?
entry into cell (by binding to receptor) unpacks nucleic acid gene expression

Genetics (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions