Brainscape's Knowledge GenomeTM

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


See full index

Molecules, cells, and organisms > lectures 44-53 > Flashcards

lectures 44-53 Flashcards

1
Q

define genomics

A

the branch of molecular biology concerned with the structure, function, evolution, and mapping of genomes

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

define genetics

A

the study of heredity and the variation of inherited characteristics

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

what is the holobiont?

A

a multicellular host and the associated beneficial microbiome

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

can plants have XY chromosomes?

A

yes but only some do

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

what are telomeres?

A

a repeat structure found at the ends of chromosomes that maintains their length

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

what is the centromere?

A

it is a spindle attachment containing satellite DNA

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

what are euchromatin and heterochromatin used for?

A

the packaging of DNA, RNA, and protein

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

what stain is commonly used to stain chromosomes?

A

Giemsa stain

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

what occurs in interphase?

A

the chromosomes and organelles replicate

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

give an overview of what occurs in prophase in mitosis

A
  • the centrosomes duplicate and begin to move
  • the chromosomes begin to condense
  • the spindle begins extending from the poles and attaches to the centromeres
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what occurs in metaphase in mitosis?

A

the centromeres align at the equator along the metaphase plate by bipolar attachment

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

what occurs in mitosis in anaphase?

A
  • the sister chromatids separate into individual chromosomes and migrate to opposite poles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what occurs in telophase in mitosis?

A
  • the chromosomes are now situated at the poles
  • the spindle disassembles
  • the nuclear membrane reforms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what occurs in cytokinesis?

A
  • the chromosomes decondense
  • cells divide
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how are sister chromatids held together and separated?

A
  • held together by cohesin
  • cohesin is destroyed enzymatically by separase breakdown of cohesin proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what occurs in prophase 1 of meiosis?

A
  • the centrosome splits and moves to the poles
  • DNA condensing begins
  • homologous chromosomes align and the synaptonemal complex forms
  • double strand breaks arise and chiasmata form
  • the nuclear membrane breaks down
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what occurs in metaphase 1 of meiosis?

A
  • kinetochores align at the equator
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what happens in anaphase 1 of meiosis?

A
  • each chromosome with 2 chromatids are pulled apart
  • independent assortment occurs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what occurs in telophase 1?

A
  • 2 haploid cells are formed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how does genetic variation occur in meiosis?

A
  • independent assortment
  • crossing over
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are the 5 stages of prophase 1 called?

A

1) leptotene
2) Zygotene
3) pachytene
4) diplotene
5) diakinesis

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

what occurs in the leptotene stage?

A
  • also known as the thin thread stage
  • chromosomes begin to condense and become visible
  • homolog pairing begins
  • double strand DNA breaks are introduced (potential sites for crossing over)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what happens in the zygotene stage?

A
  • also known as paired thread stage
  • a synaptonemal complex begins to form between homologous pairs - paired homologs are now referred to as bivalents
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what happens in the pachytene stage?

A
  • condensing of chromosomes continues
  • the synaptonemal complex is complete
  • bivalents now have 4 sister chromatids
  • crossing over is completed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what occurs in the diplotene stage?

A
  • the synaptonemal complex disassembles
  • each pair of sister chromatids begin to separate
  • chiasmata are visible (regions of crossing over between non-sister chromatids)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what happens in the diakinesis stage?

A
  • chromosomes repel each other
  • non-sister chromatids remain loosely associated via chiasmata
  • nuclear membrane and nucleolus disappear
  • monopolar attachment of chromosomes to spindle fibres occurs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what is the function of the synaptonemal complex?

A

it prevents different homolog pairs from getting entangled

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

define genotype

A

DNA based information

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

define phenotype

A

measurable expressions of the interaction between genes and the environment

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

what were the seven discrete traits studied by mendel?

A
  • round or wrinkled ripe seeds
  • yellow or green seed interiors
  • green or yellow unripe pods
  • purple or white petals
  • inflated or pinched ripe pods
  • axial or terminal flowers
  • long or short stems
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what is Mendel’s first law of inheritance?

A

heredity is controlled by paired factors or alleles of genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what is frequency of recombination?

A

the hypothesis that a smaller number of non-parental type phenotypes will be produced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

how does map based cloning occur?

A

1 - identify the gene locus from a genome-wide search of linkage to markers
2 - sequence the DNA across the locus, in both wild type and mutant variants
3 - verify function of the causal gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what is a molecular marker?

A

a difference in DNA sequence between 2 individuals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

in complete dominance, what genotypes are seen as maximum expression?

A

AA and Aa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

are discrete traits usual or unusual in plants and animals?

A

unusual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

define penetrance

A

the proportion of individuals carrying a particular variant of a gene that also expresses an associated trair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what does redundancy mean in the concept of genetics?

A

duplicate genes that provide the same function

39
Q

what are complementary genes?

A

genes in which the phenotype depends on both of the genes being functional

40
Q

how are the progeny chosen?

A

they are chose if they exhibit contrasting phenotypes and are polymorphic in many genes

41
Q

what is the statistical test for linkage?

A

LoD = log10 (likelihood that 2 loci are linked/ likelihood that 2 loci are unlinked)

42
Q

what is a simple mendelian genetic disease?

A

a single gene mutation associated with disease

43
Q

what is pedigree analysis?

A

the use of a diagram to summarise the inheritance of discreet trait in a family history

44
Q

what is the ethical limit on pedigree analysis?

A

controlled matings are not possible

45
Q

what is the sampling limit with pedigree analysis?

A

small family sizes per generation

46
Q

what are the characteristics of an autosomal recessive disease?

A
  • the disease will typically not occur in every generation
  • affected individuals can be born to unaffected parents
47
Q

what are the characteristics of an autosomal dominant disease?

A
  • in most cases DD will be lethal, so all diseased individuals will be Dd
  • disease will be found in every generation
  • males and females are equally affected
48
Q

which offspring will be affected in x chromosome sex linked recessive inheritance if the mother is a carrier?

A
  • half of the daughters will be carriers
  • half of the sons will be affected
49
Q

which offspring will be affected in x chromosome sex linked recessive inheritance if the father is a carrier?

A
  • all the daughters will be carriers
  • none of the sons will be affected
50
Q

which offspring will be affected in x chromosome sex linked dominant inheritance if the father is affected?

A
  • all daughters are affected
  • no sons are affected
51
Q

which offspring will be affected in x chromosome sex linked dominant inheritance if the mother is affected?

A
  • half the daughters will be affected
  • half of the sons will be affected
52
Q

how is linkage mapping with SSRs carried out?

A

1 - collect pedigree info from a family with history of a genetic disease and blood samples for DNA from living family members
2 - use PCR and gel electrophoresis to determine genotype of family members for several hundred SSR loci distributed throughout the genome
3 - use statistical linkage analysis to identify SSRs that are linked to inheritance of the disease allele
4 - identify how molecular markers from within the locus and repeat the linkage analysis with additional families to resolve a narrower map interval

53
Q

how do you find the causal gene of a genetic disease?

A

1 - define the locus with flanking molecular markers to a region of below 50 candidate genes
2 - identify the candidate genes within the interval that are allelic between diseased an unaffected individuals
3 - identify loss of function using knock-out analysis of genes within locus of an experimental organisms
4 = identify gain of function by genetic transformation of knock-out mutants with functional alleles

54
Q

what LoD score indicates a likelihood that a marker is located with the candidate gene?

A

above 3

55
Q

what is linkage disequilibrium?

A

a physical region observed a a non-random association of mutations amongst individuals in a population

56
Q

what is a transposable element?

A

a DNA sequence that can change in position within the genome

57
Q

define epigenetics

A

heritable changes in gene expression that are not caused by changes in DNA sequence

58
Q

what is methylation

A

methyl groups which can tag DNA and activate or repress genes

59
Q

what are histones?

A

proteins around which DNA can wind for compaction and gene regulation

60
Q

describe histone modification

A

the binding of epigenetic factors to histone ‘tails’ alters the extent to which DNA is wrapped around histones and the availability of genes in the DNA to be activated

61
Q

what biochemical evidence of mitochondrial symbiosis is there?

A

mitochondria communicate with the nucleus via trafficking of proteins and RNAs

62
Q

what genetic evidence of mitochondrial symbiosis is there?

A

the nucleus contains genes that encode mitochondrial proteins

63
Q

is the mitochondrial genome circular or linear?

A

circular

64
Q

what genes does the mitochondrial genome have?

A

it contains genes for:
- tRNAs
-rRNAs
- cytochrome oxidase
- ATPase subunits
- NADH dehydrogenase

65
Q

is the chloroplast genome circular or linear?

A

circular

66
Q

what genes does the chloroplast genome contain?

A

it contains genes for redox proteins involved in electron transport for photosynthesis

67
Q

does the chloroplast genome contain a very small or very large amount of non-coding DNA?

A

a lot

68
Q

does extranuclear inheritance involve meiotic segregation?

A

no

69
Q

how are organelles acquired in extranuclear inheritance?

A
  • organelles are acquired at cell division from the maternal cytoplasm
70
Q

why are organelles only acquired from the mother in extranuclear inheritance?

A

there are no mitochondria in the sperm head

71
Q

what are the uses of mitochondrial genome sequencing?

A
  • maternity analysis
  • phylogenetic analysis
  • population genetics
72
Q

what is genomic imprinting?

A
  • a form of gene expression in which an allele of the affected gene is marked or imprinted in one of the parents and can be passed on through meiosis to the offspring
73
Q

what is a chromosomal mutation?

A

changes in the chromosome number per cell

74
Q

are chromosomal mutations visible by microscopy?

A

yes

75
Q

what are the reasons that we would investigate chromosomal mutations?

A
  • cytological insight into meiosis
  • medical insight into causes of genetic disease
  • molecular insight of how genes interact throughout a genome
  • evolutionary insight
76
Q

define aneuploid

A

change in the number of some but not all chromosomes

77
Q

by which mechanism do autopolyploids come about?

A

endoreduplication

78
Q

by which mechanisms do allopolyploids come about?

A

hybridisation and endoreduplication

79
Q

what chemical can be used to disrupt spindle assembly and block chromosomal segregation?

A

colchicine

80
Q

what gametes are produced when meiosis occurs in a triploid?

A

aneuploid gametes

81
Q

does nondisjunction occur in meiosis one or two? what are its effects?

A
  • occurs in both meiosis 1 and 2
  • in 1, it will be lethal to all daughter cells
  • in 2, it will be lethal to half the daughter cells
82
Q

does paracentric inversion encompass the centromere?

A

no

83
Q

how can the study of population genetics be applied in real-world scenarios?

A
  • species conservation and utilisation of biodiversity
  • it is essential for genome wide association mapping
84
Q

what are the assumptions needed for Hardy Weinberg?

A
  • infinitely large population
  • random mating amongst individuals
  • no new mutations, migration, or natural selection
85
Q

what is directional selection?

A
  • it favours individuals at one extreme of a phenotype distribution which have greater reproductive success in a particular environment
    initiator: introduction of a new favoured allele, prolonged environmental change
86
Q

what is stabilising selection?

A
  • favours survival of individuals with intermediate phenotypes
  • extreme phenotypes are selected against
87
Q

what is disruptive selection?

A
  • favours the survival of two or more different genotypes that each produce different phenotypes
  • likely to occur in populations that occupy diverse environments
  • members of the populations can freely interbreed
88
Q

what is balancing selection?

A
  • two or more alleles are kept in balance and therefore are maintained in a population over many generations
89
Q

what is genetic drift?

A

random loss of alleles from a population due to chance events

90
Q

what is a genetic bottleneck?

A

a sudden decrease in population size caused by adverse environmental factors

91
Q

define the founder effect

A

dispersal and migration that establish new populations with low genetic diversity

92
Q

what is assortative mating?

A

individuals with similar phenotypes are more likely to mate

93
Q

what is disassortative mating?

A

dissimilar phenotypes mate preferentially

Molecules, cells, and organisms (2 decks)

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