Brainscape's Knowledge GenomeTM

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


See full index

BIO1M03 > Unit 1 > Flashcards

Unit 1 Flashcards

1
Q

living organism share _ traits

A

5 traits

  • made up of 1+ CELLS
  • store and process HERITABLE INFO
  • REPLICATE/REPRODUCE
  • as populations, they EVOLVE
  • use ENERGY
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Cell Theory

A
  • ALL organisms made of cells
  • ALL cells come from pre-existing cells
  • in multicellular individuals, all cells descended from a PROGENITOR CELL - the ZYGOTE
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

essential features of cells

A
  • a compartment bounded by plasma membrane
  • contents concentrated in an aq solution
  • contains molecular info (DNA) that encodes physical attributes
  • there is a boundary between them and the environment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

viruses

A
  • uses cell to replicate
  • ability to store/transmit info in RNA/DNA
  • non-living — can’t independently replicate/harness energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how was cell theory tested?

A

REIDI’S EXPERIMENT

  • two containers of meat, one open one closed
  • see which one gets maggots

PASTEUR’S EXPERIMENT

  • two containers of life giving broth. one open, one with swan neck (closed)
  • sterilized
  • open broth showed growth of life

what does this show?

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

Define a positive control and give an example

A

shows that an assumption of the experiment is true.

eg. in Louis Pasteur’s broth experiment, the open broth showed that it was capable of supporting life, supporting the experiment’s hypothesis

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

Define a negative control and give an example

A

shows what happens when a variable in an experiment is removed

eg. in Louis Pasteur’s experiment, the closed flask showed what happened when the broth was sterilized and closed.

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

name and describe parts of phylogenic tree

A

BRANCHES: populations throughout time
NODES: occur when ancestral group splits. more than two groups is a POLYTOMY
TIPS (TERMINAL NODES): groups living today or dead ends

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

define taxon

A
  • Any named group of organisms. can be a single species (Homo sapiens) or a large group of species (primates).
  • Tips connected by a single node on a tree are called sister taxa.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

define monophyletic group and an outgroup

A

MONOPHYLETIC: A group consisting of
an ancestral species and all of its descendants.

OUTGROUP: outlying popultaion in a monophyletic group. has no other nodes.

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

exception to the validity of cell theory

A

LUCA (last universal common ancestor) because we don’t know where it originated

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

exception to cell theory

A

LUCA because we don’t know if it had any ancestors. therefore we can not confirm that all cells come from other cells

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

NS acts on ____
evolution acts on ___

A

NS acts on INDIVIDUALS
evolution acts on POPULATIONS

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

key ingredients of NS

A

1) VARIATION that is
2) HERITABLE and
3) INFLUENCES FITNESS

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

why do cells exist?

A
  • CONCENTRATE REAGENTS for biological reactions
  • make CHEMICAL GRADIENTS possible across plasma membrane that can store energy
  • link a PHENOTYPE to the same physical space as the
    genotype that encodes it
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

define adaptation and characteristic

A
  • a characteristic influences fitness
    of an individual in a certain environment (not all characteristics are adaptations)
  • adaptation is the process of a species acquiring fitness-improving traits over time
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

central dogma of molecular biology

A
  • relationship between DNA, RNA and proteins (how one converts to another)
  • how information flows in biological systems.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

define speciation

A
  • when populations, usually evolving in isolation for some period of time, accumulate genetic differences that causes reproductive incompatibilities
    between them.
  • molecular variation in DNA/RNA helps us understand (nucleotides similar in closely related, less similar in less related)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

causes of speciation

A
  • GENETIC
  • ECOLOGICAL
  • BEHVIOURAL
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

domains of tree of life. how are they related.

A
  • BACTERIA
  • ARCHEA
    (both prokaryotes, lack nucleus)
  • EUKARYA (animals, fungi)
  • A and E connect to same branch
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

list of taxonomic classifications

A
  • Domain
  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus (italics)
  • species (italics, lower case)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

artificial selection

A
  • NS where humans drive course of evolution
  • repeated = changes in domestic pop over time
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

unintended consequences of artificial selection

A
  • population problems (ex only hunting large sheep, cod fishing = smaller cod)
  • in general, small size, early maturation and behavioural responses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

evidence for evolutionary change over time

A
  • FOSSILS
  • EXTINCTION
  • ancient DNA
  • TRANSITIONAL FORMS (ex limb development/loss, gaining upright posture)
  • VESTIGIAL TRAITS (ex goosebumps)
  • SPECIATION and ARTIFICIAL SELECTION can be observed now
    (ex herbicide resistance)
  • GEOGRAPHIC CONTINUITY (extinct fossil species succeeded by similar living in same region)
  • GEOGRAPHIC RELATIONSHIPS: close relations of living species across different locations
  • HOMOLOGY (genetic, developmental,
    structural)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

homology: genetic and developmental

A

a similarity that exists in species that was inherited from an ancestor

GENETIC: similarity among species in DNA sequences, gene content, or other genetic attributes that is due to shared ancestry

DEVELOPMENTAL: similarity among species
in embryonic traits that is due to shared ancestry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

why does homology matter?

A
  • toxins and allergies may similarly affect closely related species
  • medicines can be tested in other species
  • Biological function in humans can be inferred from homologous function in other species
27
Q

4 processes that drive evolution/change allele frequency

A

1) NATURAL SELECTION
2) GENETIC DRIFT
3) GENE FLOW (migration)
4) MUTATION

28
Q

theory of evolution

A

a) species are related to each other
b) species can change through time

29
Q

fitness

A

ability of an individual to produce
offspring as compared to other individuals of the same
species

30
Q

define evolution

A

a change in allele frequency in a population over time

31
Q

polymorphic

A

A species that has two or more distinct phenotypes in the same interbreeding population at the same time

ex. 2 different strains of tuberculosis, one is antibiotic resistant one is not

32
Q

morphology

A

The overall shape and appearance of an organism and its component parts.

33
Q

in situ hybridization

A

Technique for detecting specific DNAs and mRNAs in cells and tissues by use of labelled complementary probes.
Can be used to determine where and when particular genes are expressed in embryos.

34
Q

myths about evolution

A
  • not goal/want/need directed
  • no hierarchy of life
  • no altruism
  • doesn’t result in most optimal phenotype
35
Q

Why doesn’t natural selection result in
the most optimal phenotype?

A
  • Genetic Correlation: fitness trade-off
  • Historical Constraints: Present variation biases future possibilities
  • Formal Constraints: can’t defy laws of physics
  • Temporal Constraints: evolution occurs by mutation and may take a long time to happen
36
Q

gene flow

A

causes change in allele freq. through migration

37
Q

genetic drift

A

causes change in allele freq. randomly generation to generation

38
Q

purpose of hardy-weinberg principle

A

to create a null hypothesis to help better understand what mechanisms of evolution are influencing a population

39
Q

heterozygote advantage

A
  • A pattern of natural selection that favours heterozygous individuals
  • Tends to maintain genetic variation in a population and thus is a form of balancing selection.
40
Q

directional selection

A
  • mode of NS that changes the average value of a trait (shifts it more towards a favourable characteristic)
  • reduction in genetic diversity
41
Q

stabilizing selection

A

mode of NS that favours phenotypes near the middle of the range of phenotypic variation.
- Reduces genetic variation in a population

42
Q

types of natural selection

A
  • balancing selection (no allele favoured)
  • directional selection
  • stabilizing selection
  • disruptive selection
  • frequency dependant selection (neg and pos)
43
Q

disruptive selection

A

-mode of NS that maintains or increases amount of variation in a trait (double bell curve)

44
Q

negative frequency dependant selection

A

fitness highest in rare phenotypes

45
Q

positive frequency dependant selection

A

fitness highest in common phenotypes

46
Q

genetic drift

A
  • any change in allele freq. in a population due to CHANCE
  • not adaptive changes
  • can lead to stochastic loss/fixation: genetic variance in pop declines
  • more prominent in small populations
47
Q

fixation vs extinction

A

caused by genetic drift
Fixation: only one allele survives
other allele is extinct

48
Q

causes of genetic drift

A

random even or process that involves sampling of allele from one gen to the next

eg. founder effect and bottlenecks

49
Q

how does founder effect cause genetic drift

A

population isolation causes decreased alleleic variation

50
Q

how do bottlenecks cause genetic drift

A

SEVERITY + DURATION impact strength of bottleneck in decreasing allelic variation

51
Q

gene flow

A

migration
movement of alleles from one pop to another.
homogenizes allele frequencies across populations

52
Q

nonrandom mating

A

biased mating

examples: inbreeding, sexual selection

53
Q

inbreeding

A
  • increases frequency of homozygotes (homozygosity) and reduces frequency of heterozygotes in each generation

does NOT change allele frequency, DOES change genotype frequency

54
Q

inbreeding depression, causes

A
  • decline in fitness from increasing homozygosity and decreasing heterozygosity

causes:
1) many harmful mutations are recessive
2) heterozygote advantage

** DOES change allele frequencies because
1) harmful homozygous recessives more common
2) beneficial heterozygous genotypes less common
these two things make individuals less fit, therefore NS acts on allele frequencies

55
Q

red queen hypothesis

A

species must constantly evolve to avoid extinction as a consequence of being outcompeted by
other evolving competitors.

56
Q

why sex?

A

asexual reproduction will win over sexual every time BUT…

  • males can help out with ‘parenting’
  • male competition: better genes, less mutations
  • genetic recombination benefit to offspring
57
Q

genetic recombination

A
  • natural selection ‘placing’ good and bad mutations together in order to maximize fitness
58
Q

isogamous species

A

all individuals produce the same gametes (ex yeast)

59
Q

how does sexual selection violate HWE

A

by causing certain alleles to increase or decrease in frequency, resulting in evolutionary change.

60
Q

consequences of sexual selection

A

sexually dimorphic traits
sexual conflict (traits that are advantageous in one sex but harmful in another)

61
Q

pros and cons of sexual reproduction

A

PROS
- male parental care
- SS removes bad alleles
recombination

CONS
- have to make males (2 fold cost of sex)
- may disrupt advantageous combinations of alleles
- can be risky (std, predation)

62
Q

causes of sexual selection

A

female choice
- honest advertising
- nuptial gifts

male male competition

sensory exploitation

63
Q

evidence for sexual selection in males

A

variation in reproductive success high in males, low in females.

more females have offspring, only few males have many.

64
Q

mechanisms of reproductive isolation

A

Prezygotic isolation
- temporal
- habitat
- behavioural
- gametic barrier
- mechanical

postzygotic isolation
- hybrid viability (embryos don’t develop properly)
- hybrid sterility (sterile offspring)

BIO1M03 (11 decks)

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