Brainscape's Knowledge GenomeTM

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


See full index

Fundamentals of the Living Cell > Introduction to Evolution I&II > Flashcards

Introduction to Evolution I&II Flashcards

1
Q

what is evolution?

A

the accumulated, heritable changes within a population over generations, giving a rise to new species

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

what is taxonomy?

A

naming of groups of organisms (taxa).

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

what is classification?

A

arrangement of taxa into an ordered, hierarchical system according to their observed similarities.

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

what is phylogeny?

A

phylogeny is the determination of ancestral relationships or organisms and their evolutionary history.

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

what are phylogenetic trees?

A
  • phylogenetic relationships can be represented using phylogenetic trees.
  • the Phylogenetic Tree of Life illustrates that all Bacteria, Archaea and Eucaryota are derived from a distant, common ancestor called LUCA.
  • a phylogenetic tree can also be based on morphological criteria.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how can organic material and rocks be dated?

A

rock and organic material can be dated by measuring the decay of naturally occurring radioactive isotopes

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

where do fossils usually form and how are they dated?

A
  • fossils usually form in sedimentary rock.

- fossil dates can be bracketed by the age of surrounding igneous rock.

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

how do fossils form?

A

1) There are surface erosions that occur, creating sediment.
2) When an organism dies, it settles onto the sediment, which then becomes sedimentary rock.
3) Thus, a fossil forms of that organism.
4) The soft sediment preserves the fine details in the bones, teeth, and leaves of plants.

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

how does the fossil record provide evidence for evolution? and what does it allow?

A
  • the fossil record allows for the order and age of organisms to be determined.
  • simpler life forms are present in older rock.
  • we also find fossilised organisms that no longer exist.
  • proves that evolution takes place, for more complex organisms to have evolved from the simpler organisms, and for the extinct organisms to have died out due to their inability to survive in the environment.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is radiometric dating? and what are radioisotopes used for?

A
  • measuring the ratio of parent/daughter nuclides.

- radioisotopes can be used to date rocks and fossils.

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

what are some requirements for radiometric dating?

A
  • the rate of radioactive decay is constant: not affected by temperature, pressure, chemicals, electrical or magnetic fields
  • the parent and daughter nuclides cannot leave or enter material after it is formed
  • there must be no intrusion of other, later rock
  • there must be no contamination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is homology in terms of evolution?

A

similarity by descent- a common ancestor

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

what is analogy in terms of evolution?

A

similarity by function- no common ancestor but due to selective pressures of the environment

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

what is molecular analogy and give an example?

A
  • molecular convergence
  • when proteins have the same function with no structural identity.
  • an example would be crystallins (lens proteins) There are many different transparent proteins in different species.
  • they all have other functions (in addition to being stable, transparent and refractive).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is molecular homology?

A

determined by aa or nucleic acid sequence

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

what are the two types of molecular homology?

A

1) paralogs: 2 genes from the same organism

2) orthologs: 2 genes from different organisms

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

how is gene duplication a key driver in evolution?

A
  • when a gene is duplicated, the original gene can go back to executing it’s original function.
  • the duplicated gene is free to be modified.
  • it may perform functions complementary to the original gene’s function (acting as a backup).
  • it can also evolve non-overlapping functions.
18
Q

how did the influenza virus change so rapidly?

A

different flu strains infecting the same cell can swap parts of their genetic material.

19
Q

give an example of evolution that has been observed

A
  • 12 colonies of E. Coli from a single clone
  • subculture it every day, for 27 years
  • freeze the culture samples every 500 generations (75 days)
  • over the completed experiment, 63,500 generations would have been observed
  • test the cultures for the ability to grow in citrate in the presence of oxygen
  • the ability to use citrate evolved after about 30,000 generations in one group in particular.

-earlier generations from this same ancestral E. Coli were repeatedly able to evolve the ability to utilise citrate at about the same time.

20
Q

what are examples of little mistakes during DNA replication?

A
  • small duplications
  • small insertions
  • small deletions
  • base substitution
21
Q

what are examples of big mistakes during DNA replication?

A
  • large DNA duplications
  • chromosome rearrangements
  • large deletions
  • viral insertions
  • insertion transposable elements
22
Q

what is natural selection?

A

organisms that possess favourable phenotypes are likelier to survive and produce more offspring

23
Q

what is genetic drift?

A

variation in relative frequency of genotypes in small populations due to chance

24
Q

what is gene flow?

A

transfer of alleles from one population to another

25
Q

what is applied selection?

A
  • plants or animal breeding

- antibiotics, drug, pesticide resistance

26
Q

what drives species evolution?

A

gene evolution

27
Q

what are HOX genes?

A
  • developmentally important transcription factors

- they determine where the gene is expressed

28
Q

how do populations evolve?

A

changes in gene frequency brought about by random genetic drift, gene flow and natural selection

29
Q

what is speciation?

A

gradual evolution of reproductive isolation amongst populations

30
Q

what is the endosymbiosis theory?

A
  • endosymbiotic theory deals with the origins of mitochondria and chloroplasts
  • mitochondria and chloroplasts are believed to have developed from symbiotic bacteria.
31
Q

what is the evidence of the endosymbiosis theory?

A
  • mitochondria have their own circular genome which replicates independently of nuclear DNA
  • new mitochondria are produced by fission of existing mitochondria
  • all mitochondrial genomes share similarity with the Typhus bacterium “Rickettsia prowazekii”
32
Q

what are plastids and where are they found?

A

the plastid is a major double-membrane organelle found in the cells of plants, algae, and some other eukaryotic organisms.

33
Q

what are the four basic processes of multicellularity?

A
  • spatial organisation
  • change in form
  • growth
  • differentiation
34
Q

describe why the evolution of the eye is thought of as being convergent

A
  • the diversity of eyes suggests that they have evolved several times independently (polyphyletic, convergent evolution).
  • they also have features in common.
35
Q

what are the common features of eukaryotic eyes?

A
  • ALL eukaryotes use a homologous family of proteins, opsins, to detect light.
  • opsins are G-protein coupled receptors that convert light to nerve impulses.
  • eukaryotic opsins share sequence homology and have diverged to detect different wavelengths of light.
36
Q

how many Hox genes do vertebrates have and how have they arisen?

A
  • vertebrates have 4 hox gene clusters

- arisen from two duplication events of an ancestral chromosome.

37
Q

what does Pax 6 have to do with the development of the eye?

A
  • being eyeless is orthologous to Pax6 in humans and mice.
  • the ectopic (differently placed) expression of the eyeless gene in drosophilia (fruit flies) leads to ectopic eyes.
  • Pax6 is involved in eye development throughout the animal kingdom.
38
Q

how can eye loss occur as a result of evolution? and give an example

A
  • some animals have evolved from surface-dwelling forms to underground forms
  • eye loss is a common feature in such animals because eyes are energetically expensive
  • Mexican, blind cavefish
  • its surface-dwelling ancestor has eyes, but the derived, cave-dwelling form doesn’t.
39
Q

how do we know where Homo-sapiens come from?

A
  • the mitochondrial genome replicates independently of the nuclear genome and does not undergo recombination
  • the male Y chromosome does not have a homologous female chromosome to recombine with.
  • changes in sequence of mtDNA and the Y chromosome are due to random mutations over time.
  • analysis of mtDNA and Y chromosome sequence shows maternal and paternal origin, respectively.
40
Q

what is the RNA world hypothesis?

A
  • early life is thought to have been based on self-replicating and self catalyzing RNA molecules
  • catalytic RNAs are present in organisms from bacteria to humans
41
Q

why did RNA world evolve into DNA?

A
  • DNA > stable than RNA

- there is a greater range of protein enzymes and they are more robust

Fundamentals of the Living Cell (31 decks)

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