Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BIOL1003 > deck_18695468 > Flashcards

deck_18695468 Flashcards

(81 cards)

Start Studying
1
Q

Allele

A

An allele is a version of a gene

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

Mutations

A

Changes to the genome: Somatic mutations affect body cells & are not heritable, Germ-line mutations affect gametes. Only they are heritable.

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

Genotype

A

The genetic makeup of an organism, the code of ACGT

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

Polygenic traits

A

Traits that are determined by more than one gene

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

Phenotype

A

The phenotype is the outward, physical expression of genotype

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

Genotype by Environment interaction

A

Nonadditive interaction; in different environments, different genes do different things.

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

Phenotypic plasticity

A

Selection favouring changes in phenotype over an organism’s lifetime

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

Adaptive phenotypic plasticity

A

If the change in response to the environment increases fitness

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

Microevolution

A

Refers to small changes over short periods of time within a population (species).

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

Macroevolution

A

Refers to larger changes over a much longer time scale. Can result in speciation or the emergence of new species - or extinction

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

Evolution

A

Changes to relative frequency of replicating units over time, leading to changes in populations over time

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

Genetic drift

A

Sampling error over time. (Allele frequency changes by chance)

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

Genetic bottleneck

A

Small sample at one point in time, due to events within population or by a spatial bottleneck (founder effect)

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

Gene flow

A

Immigration of new genes between populations

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

Natural selection

A

Evolution that occurs in a directional way to result in a greater fit between organism and environment.

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

Adaptations

A

An inherited aspect of an individual that allows it to outcompete others that lack or have a different version of the trait.

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

Fitness

A

The expected reproductive success of an individual with a particular phenotype

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

Reproductive value

A

An offspring with high reproductive value will have more children (and grandchildren)

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

Optimality

A

In a constant environment, there will usually be an optimal design

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

Pleiotropy

A

Most genes affect multiple traits

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

Trade-offs

A

Genes have good and bad effects depending on environment

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

Limit of selection

A

Mutation must introduce variation faster than selection eliminates it; in small populations, drift can outweigh selection

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

Artificial selection

A

Selection caused by humans with a defined goal

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

Human-induced selection

A

Selection unintentionally caused by humans (e.g., urbanization)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Directional selection
Favors one extreme (e.g., peppered moths)
26
Stabilizing selection
Favors the mean, reduces variation (e.g., birth weight in humans)
27
Disruptive selection
Favors extremes, reduces the average (e.g., beak size in finches)
28
Negative frequency-dependent selection
The rarer the trait the better it does. Being rare increases survival or reproductive success.
29
Positive frequency-dependent selection
The more common the trait, the better it does.
30
Sexual selection
Advantage in mating competition (e.g., ornaments, weapons, courtship)
31
Sexual conflict
A trait that benefits one sex but reduces the fitness of the other
32
Co-evolution
One organism's change drives changes in another (e.g., predator-prey)
33
Heritability
The ability of a trait to be passed to offspring
34
Additive genetic variation
Effect of multiple loci adding up to a trait Both genotype and environment determine (add up to) phenotype
35
Heterosis / Heterozygous advantage
Heterozygotes have higher fitness (e.g., sickle cell) | in malaria prevalent areas
36
Balancing selection
Maintains genetic variation (e.g., heterozygous advantage)
37
Antagonistic pleiotropy
Good and bad effects depending on the environment
38
Temporal variations in selection
Selection pressure changes over time
39
Individual selection
Genes that increase individual fitness spread
40
Group selection
Selection 'for the good of the group' (controversial)
41
Good of the species
Traits that benefit group survival | controversial
42
Gene’s eye view (selfish gene)
Genes promote their own replication
43
Kin selection
Helping relatives increases inclusive fitness | Inclusive fitness is sum of direct and indirect fitness
44
Biological species concept
Species are interbreeding populations reproductively isolated from others
45
Reproductive isolation
Barriers to reproduction (physical, genetic, behavioral)
46
Pre-zygotic barriers to gene flow
Mating or fertilization does not occur
47
Post-zygotic barriers to gene flow
Fertilization occurs but offspring fail (e.g., sterile, non-viable hybrids)
48
Hybridization
Cross between two species
49
Genetically incompatible
Mating results in non-viable or defective offspring
50
Hybrid zones
Areas where different populations interbreed with low-fitness hybrids
51
Ring species
A connected series of populations where endpoints cannot interbreed
52
Behavioural isolation (speciation)
Mating preferences differ
53
Gametic isolation (speciation)
Egg-sperm incompatibility
54
Temporal isolation (speciation)
Breed at different times
55
Habitat isolation (speciation)
Different living areas
56
Mechanical isolation (speciation)
Physical mismatch of reproductive parts
57
Allopatric speciation
Populations become geographically isolated | Galapagos finches, anole lizards
58
Sympatric speciation
Speciation in the same place. Requires: currently within range, substantial reproductive isolation, must be sister taxa, allopatric speciation must be very unlikely | Can happen by polyploidy especially in plants
59
Polyploidy
More than two sets of chromosomes
60
Autopolyploidy
Chromosome duplication in one species due to error in meiosis. Self-fertilisation can create a new species
61
Allopolyploidy
Hybridization (two species). Gametes of A and B fuse, if different numbers then chromsomes cant pair so hybrid is infertile If hybrid has even number of chromosomes or undergoes autopolyploidy it may become fertile
62
Magic trait
Trait under selection that also affects mating (e.g., host choice in flies) Apple maggot flies feed and mate on same plants, some went to hawthorns, some to apples. Offspring mate on plant type their were raised on.
63
Phylogeny
A tree showing hypothesized evolutionary relationships
64
Sister species
Share a recent common ancestor
65
Clades
Ancestor and all descendants
66
Monophyletic
Valid group including all descendants
67
Paraphyletic
Misses some descendants
68
Polyphyletic
Includes unrelated lineages
69
Common ancestor
Shared evolutionary origin
70
Derived traits
Evolved traits passed to descendants
71
Convergent evolution
Similar traits from different lineages
72
Secondary loss
Loss of an evolved trait
73
Horizontal gene transfer
Genes passed across species (e.g., via viruses)
74
Branch lengths (phylogeny)
Indicate time or amount of change
75
Tip | Of a phylogeny
Represents a species
76
Molecular clocks
Use mutation rates to estimate evolutionary time
77
What are the key terms/steps when explaining evolutionary changes in scientific language?
1. Selection pressure 2. What is the trait under selection 3. What is the favourable trait that overcomes the selection pressure 4. How does the favourable trait confer an advantage 5. What type of selection is acting?
78
What is required for natural selection?
1. Variation 2. Heritability 3. A statistical relationship between trait and fitness
79
What is the fitness of a gene?
average change in relative fitness when inheriting an allele
80
What are the pre-zygotic barriers?
**Pre-mating** Ecological isolation: temporal, habitat, pollinators Behavioural isolation Mechanical isolation **Post mating** Gametic isolation
81
What are the post-zygotic barriers?
Reduced hybrid vigour or attractiveness Reduced hybrid fertility

BIOL1003 (5 decks)

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