Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BI302 > Chapters 4,5+6 > Flashcards

Chapters 4,5+6 Flashcards

(76 cards)

Start Studying
1
Q

What do phylogenetic trees represent?

A

the branching pattern of evolution over time

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

Who proposed evolution being like a branching tree?

A

Darwin

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

Why are phylogenetic trees advantageous?

A

Because we can understand how and when species evolve and as simply or as complex as we may need

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

what is a branch in a phylogenetic tree

A

a lineage evolving through time that connects successive speciation

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

what is phylogeny

A

a visual representation of evolutionary history

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

What are nodes in a tree

A

points in a phylogeny where a lineage splits

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

What is a clade

A

single branches in the tree of life, each clade represents an organsim and all of its descendants

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

what is monophyly

A

a group of organisms that for a clade

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

what is polyphyly

A

a taxon that does not include the common ancestor of all members of the taxon

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

what is paraphyly

A

a group of organisms that share a common ancestor but not all the descendants

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

what do split branches in trees represent

A

a trait change or addition to a common ancestor in the tree itself

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

what are taxa

A

groups of organisms that a taxonomist judges

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

what is synapomorphy

A

a derived form of a trait that is shared by a group of related species

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

what is an outgrup

A

group(s) of organisms that are outside the monophyletic group being considered

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

what is convergent evolution

A

the independent origin of similar traits in separate evolutionary lineages

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

All phylogenetic trees are a _________

A

hypothesis

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

what is parsimony

A

a principle that guides the selection of alternative hypotheses, the alternative requiring the fewest assumptions or steps is usually best

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

trees are most accurate when they have shared ______ characters

A

derived

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

what is horizontal gene transfer

A

it describes the transfer of genetic material-other than parent to offspring- to another organism without reproduction

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

what is evolutionary reversal

A

describes the reversion of a derived character state to a form resembling its ancestral state

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

what is polytomy

A

describes an internal node with more than two branches

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

What are the three types of mammals

A

monotremes, marsupials and eutherians

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

what are monotremes

A

do not have specific nipples for secreting milk and lay eggs like birds (ex. platypus)

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

what are marsuipals

A

young crawl into pouch of mothers belly after birth and are carried until they can survive on their own (ex. kangaroo)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what are eutherian mammals
develop a placenta to feed embryos to the uterus
26
what part of the human body can tell us a lot about our phylogeny
the inner middle ear
27
what is exaptation
a trait that initially carries out one function and is later opted for a new function (eg. feathers)
28
what are the three kinds of molecules that are especially important for evoluion
DNA RNA and proteins
29
proteins are made up of ...
amino acids :-)
30
what is gene expression
the the process by which information from a gene is transformed into a product
31
what is the role of RNA polymerase
the enzyme that buildsthe single stranded RNA molecule from the DNA template during transcription
32
translation happens inside the ________.
ribosome
33
what is the gene control region
upstream section of DNA that includes the promoter region that influence the transcription of DNA
34
what is a repressor
proteins that bind DNA or RNA and inhibit the expression of genes
35
what is a transcription factor
proteins that bind to specific DNA sequences and act like a lightswitch turning sequences on and off
36
what are enhancers
short sequences of DNA within the gene control region where activator proteins bind to activate gene expression
37
what is RNA splicing
modifying RNA after transcription but before translation where introns are removed and exons are joined together to create a continuous strand
38
what is alternative splicing
process of comining different subsets of exons together, yeilding different mrNA transcripts from a single gene
39
in humans, the average gene can splice to express one of __ different proteins
six
40
proteins can be modified even after translation (T or F)
T, called post-translational regulation
41
what is epigenetic
the functional modifications of DNA that do not involve nucleotides
42
what is a genome
all the hereditary infromation of an organism
43
what are pseudogenes
genes that can no longer produce a functional molecule
44
mutations happen within the ____
mRNA
45
what is aneuploidy
chromosmoes are duplicated or lost leading to an abnormal number or chromosomes
46
what are cis acting elements
stretches of DNA located near a gene that influence the expression of that gene, often binding sites
47
what are transacting elements
sequences of DNA located away from the focal gene that generally code for a protein or other molecule that then influences expression of the focal gene
48
what are germ-line mutations
mutation that affect the gametes and can be transmitted from parents to offspring
49
what is genetic polymorphism
the simultaneous occurenceof two or more discrete phenotypes within a population
50
what is polyphenism
a trait for which multiple discrete phenotypes can arise from a single genotype depending on environmental circumstances
51
what is a morphogen
a signaling molecule that flows between nearby cells and acts directly to later expression of target genes
52
what is phenotypic plasticity
refers to changes in the phenotype produced by a single genotype if a different environment
53
what is population genetics
the study of the distribution of alleles within a population and the mechanisms that can cause allele frequencies to change over time
54
what is a genetic locus
specific location of a gene or piece of DNA sequence on a choromosome
55
what is hardy-weinberg equilibrium
in the absence of drift, selection, migration and mutation, allele frequencies at a genetic locus will not change from one generation the the next
56
what is a null hypothesis
default hypothesis that concludes that no changes were found
57
what is a fixed allele
an allele that remains in a population when all of the alternative alleles have dissapeared
58
the smaller the population sample, the ____ deviations you will have (more or less)
more
59
what is a genetic bottleneck
an event in which the number of individuals in a population is reduced drastically
60
What is the founder effect
type of genetic drift that describes the loss of allelic variation that takes a small population from a larger one and colonizes in a different environment
61
The reproductive success of a particular phenotype is known as _______
fitness
62
what is relative fitness(of a genotype)?
the success of the genotype at producing new individuals standardized by the entire success of all the fitness of other genotypes
63
what is pleiotropy
the condition when a mutation in a single gene affects the expression of more than one different phenotypic trait
64
what is antagonistic pleiotropy
occurs when when a mutation with beneficial effects for one trait also causes effects on other traits
65
what is negative selection
selection that decreases the frequency of alleles in a population
66
what is posititve selection
selection that increases the frequency of alleles in a population
67
what is epistasis
occurs when the effects of an allele at one genetic locus are modfied by alleles at one or more loci
68
what is an additive allele
an allele that yields twice the phenotypic effect when two copies are present versus one
69
are dominant and recessive alleles additive?
no
70
what is inbreeding depression
reduction in the average fitenss of inbred individuals relative to that of outbred individuals
71
inbreeding (increases/decreases) the precentage of genetic loci that are homozygous for alleles and changes allele frequenceis
increases
72
what is genetic distance
a measure of how different populations are from each other genetically
73
what is gene flow
movement or migration of alleles from one population to another
74
population subdivision increases the effects of _____ ____.
genetic drift
75
what is the average excess of fitness
the difference between the average fitness of individuals bearing the allele and the average fitness of the population as a whole
76
what is the inbreeding coefficient
the probability that two alleles at any locus will be identical because of common descent

BI302 (3 decks)

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