Zoology 415

0.0(0)
Studied by 0 people
call kaiCall Kai
learnLearn
examPractice Test
spaced repetitionSpaced Repetition
heart puzzleMatch
flashcardsFlashcards
GameKnowt Play
Card Sorting

1/108

encourage image

There's no tags or description

Looks like no tags are added yet.

Last updated 2:39 PM on 4/30/26
Name
Mastery
Learn
Test
Matching
Spaced
Call with Kai

No analytics yet

Send a link to your students to track their progress

109 Terms

1
New cards
Why is ancient DNA highly fragmented?
DNA degrades over time due to chemical damage and environmental exposure, breaking into short fragments
2
New cards
Why does cytosine deamination matter in ancient DNA?
It causes characteristic C→T errors that indicate DNA damage
3
New cards
Why do ancient samples contain mostly microbial DNA?
Microbes contaminate and outcompete endogenous DNA over time
4
New cards
Why is contamination especially problematic in ancient DNA?
Low endogenous DNA makes real signal hard to distinguish from contamination
5
New cards
Why does heat accelerate DNA degradation?
It increases chemical reactions that break DNA bonds
6
New cards
Why does UV damage DNA?
It creates mutations like thymine dimers that disrupt sequences
7
New cards
Why are cold environments better for DNA preservation?
They slow chemical reactions and microbial growth
8
New cards
9
New cards
Why is ancient DNA more informative than modern DNA?
It directly samples past populations instead of inferring history indirectly
10
New cards
What can ancient DNA reveal about populations?
Migration, admixture, and population replacement
11
New cards
Why does low coverage increase uncertainty?
Fewer reads reduce confidence in detected variants
12
New cards
13
New cards
What do f-statistics measure?
Allele sharing between populations
14
New cards
What does excess allele sharing indicate?
Gene flow or admixture
15
New cards
What does reduced allele sharing indicate?
Population divergence
16
New cards
Why are f-statistics better than simple trees?
They detect gene flow that trees cannot represent
17
New cards
18
New cards
Why do humans have Neanderthal DNA but not mtDNA?
Suggests sex-biased admixture or selection removed Neanderthal mtDNA
19
New cards
Why is mtDNA more easily lost than autosomal DNA?
It is inherited as a single unit without recombination
20
New cards
Why can autosomal DNA retain introgression?
Recombination allows small segments to persist
21
New cards
22
New cards
Why are introgressed segments short in modern humans?
Recombination breaks them over generations
23
New cards
What does segment length indicate?
Longer segments mean recent admixture, shorter mean older admixture
24
New cards
Why is recombination considered a clock?
It steadily breaks DNA each generation
25
New cards
26
New cards
Why do East Asians have more Neanderthal ancestry than Europeans?
Possibly due to multiple admixture events or different selection pressures
27
New cards
Why do Melanesians have Denisovan ancestry?
Their ancestors encountered Denisovans during migration
28
New cards
29
New cards
Why is most introgressed DNA removed?
Negative selection removes harmful variants
30
New cards
Why can introgressed DNA be harmful?
Genetic incompatibilities reduce fitness
31
New cards
Why is adaptive introgression rare?
Most foreign alleles are not beneficial
32
New cards
33
New cards
Why is EPAS1 adaptive introgression?
It improves survival at high altitude and came from archaic humans
34
New cards
35
New cards
What are structured populations?
Semi-isolated populations exchanging genes over time
36
New cards
Why does structured evolution increase diversity?
Different groups evolve separately before mixing
37
New cards
What evidence supports structured populations?
Deep divergence, fossil gaps, regional traits
38
New cards
39
New cards
Why can genealogical ancestors not contribute DNA?
Recombination dilutes DNA over generations
40
New cards
What is genetic vs genealogical ancestry?
Genetic ancestry includes only ancestors who contributed DNA
41
New cards
Why does genetic ancestry shrink over time?
DNA segments are lost through recombination
42
New cards
43
New cards
What is IBS?
Shared allele not necessarily from a common ancestor
44
New cards
What is IBD?
Shared DNA from a common ancestor
45
New cards
Why is IBD more meaningful than IBS?
It reflects true shared ancestry
46
New cards
47
New cards
Why do close relatives share long DNA segments?
They inherited large segments from a recent ancestor
48
New cards
Why do distant relatives share small segments?
Recombination breaks DNA over generations
49
New cards
Why can distant relatives appear unrelated?
Segments may be too small to detect
50
New cards
51
New cards
Why are genotyping arrays biased?
They only include selected SNPs
52
New cards
When is whole genome sequencing preferred?
When complete unbiased data is needed
53
New cards
Why are arrays still used?
They are cheaper and faster
54
New cards
55
New cards
Why does shared DNA decrease with relatedness?
Recombination reduces segment size and number
56
New cards
Why does recombination weaken ancestry signals?
It fragments shared DNA
57
New cards
58
New cards
Why do all humans share recent ancestors?
Population mixing over time leads to shared ancestry
59
New cards
Why does shared ancestry not mean identical DNA?
Recombination creates unique combinations
60
New cards
61
New cards
Why can someone be identified through a relative?
Relatives share identifiable DNA segments
62
New cards
Why does database size increase match probability?
More people increase chances of overlap
63
New cards
What is the tradeoff in DNA databases?
More matches vs privacy concerns
64
New cards
65
New cards
Why is inheritance noisy?
DNA is randomly inherited, not evenly passed
66
New cards
Why does noise affect distant matching?
Shared DNA may be too small to detect
67
New cards
68
New cards
Why are genealogy databases stronger than CODIS?
They use genome-wide data
69
New cards
Why is CODIS limited?
It uses few markers for identification only
70
New cards
71
New cards
Why can GWAS not prove causation?
It detects correlation, not cause
72
New cards
What is population stratification?
Differences between groups that create false signals
73
New cards
Why does stratification bias GWAS?
Environmental or ancestry differences mimic genetic effects
74
New cards
75
New cards
What is heritability?
Proportion of trait variation due to genetics
76
New cards
Why is heritability not determinism?
Environment also influences traits
77
New cards
Why does heritability vary across populations?
Different environments and genetic backgrounds
78
New cards
79
New cards
What is missing heritability?
Genetic variation not explained by GWAS
80
New cards
Why do rare variants contribute?
They are not captured well in SNP studies
81
New cards
Why do gene interactions matter?
Effects depend on combinations of genes
82
New cards
Why does environment matter for heritability?
It influences trait expression
83
New cards
84
New cards
What are polygenic risk scores?
Sum of effects of many SNPs
85
New cards
Why are PRS limited?
They capture only part of genetic variation
86
New cards
Why do PRS fail across populations?
SNP effects differ by ancestry
87
New cards
Why can siblings have different PRS?
They inherit different allele combinations
88
New cards
Why are PRS probabilistic?
They predict likelihood, not outcome
89
New cards
90
New cards
Why do PRS predictions fail in real life?
Environment and randomness influence traits
91
New cards
Why is PRS accuracy low?
It explains only a fraction of variance
92
New cards
93
New cards
Why does embryo selection give small gains?
Prediction accuracy is limited and variance is high
94
New cards
Why does more embryos not guarantee better traits?
Genetic variation is limited
95
New cards
Why is embryo selection controversial?
Ethical concerns about genetic selection
96
New cards
97
New cards
How does CRISPR target DNA?
Guide RNA binds complementary sequence and directs Cas9
98
New cards
Why can CRISPR hit the wrong target?
Similar sequences cause off-target binding
99
New cards
Why are off-target effects dangerous?
They create unintended mutations
100
New cards
Why is CRISPR powerful?
It enables precise genome editing