evolution review for exam Flashcards
(25 cards)
Which of the following is NOT correct?
Question 1 options:
Darwin’s theory held that species can arise by evolution from other species, while Lamarck’s theory did not.
Darwin’s theory is a much better fit to Linnaean (hierarchical) taxonomy than was Lamarck’s theory.
Lamarck’s theory required that characteristics of individuals can change within their lifetimes, whereas Darwinian natural selection requires that populations include individuals with intrinsic, heritable differences.
Lamarck imagined (incorrectly) that life arose many times, and that each lineage increased in complexity over time.
Darwinian natural selection results in adaptation to the environment in which a species lives.
Darwin’s theory held that species can arise by evolution from other species, while Lamarck’s theory did not.
Which of the following conditions are required for natural selection to take place?
Question 2 options:
That individuals have differing traits that are heritable.
That there is use and disuse of parts
That there was a single origin of life on Earth
A and B are both required
A, B and C are all required
That individuals have differing traits that are heritable.
Which of the following pairs of structures are homologous?
Question 3 options:
Bat wings; Human arms
Bat wings; Insect wings
Bat wings; Whale flippers
Both A and C
A, B and C
Both A and C
Consider two closely related species of animals, X and Y; X has wings, Y has vestigial wings. From this information, which of the following is most likely correct?
Question 4 options:
The most recent common ancestor of X and Y had wings
The most recent common ancestor of X and Y had vestigial wings
The most recent common ancestor of X and Y had both wings and vestigial wings
The most recent common ancestor of X and Y had no wings at all (the wings of X and vestigial wings of Y evolved separately)
Either answer C or answer D could easily be correct – we cannot tell which
The most recent common ancestor of X and Y had wings
Living whales are fully aquatic mammals that, unlike land mammals, lack hindlimbs. However, fossil skeletons of some extinct whales include bones of the upper and lower hind leg and some foot bones. Which of the following options best describes this situation?
Question 5 options:
The extinct whale’s hindlimbs arose through convergent evolution (convergent with land mammals)
These extinct whales are more closely related to land animals than they are to modern whales
These extinct whales must be the last common ancestors of living whales
These extinct whales must represent a different branch on the tree of life than modern whales
These extinct whales represent a transitional form between land mammals and modern whales
These extinct whales represent a transitional form between land mammals and modern whales
Which of the following can cause microevolution in a population?
Question 1 options:
Natural selection
Gene flow
Genetic drift
Both A and C
Any of A, B and C
Any of A, B and C
A population of a species has two alleles, “B” and “b”, at some locus. The population has 68 BB individuals, 20 bb individuals and 12 heterozygotes. What is the frequency of allele “B” in the population?
Question 2 options:
0.4
0.46
0.68
0.74
0.8
0.74
Consider a single locus where there is one dominant and one recessive allele. 9% of a population shows the homozygous recessive genotype (i.e. the frequency of this genotype is 0.09). What is the expected frequency of the dominant allele in this population, if we assume that the population is in Hardy-Weinberg equilibrium?
Question 3 options:
0.3
0.49
0.7
0.81
0.97
0.7
Consider a single locus where there is one dominant and one recessive allele. 9% of a population shows the homozygous recessive genotype (i.e. the frequency of this genotype is 0.09). What is the expected frequency of heterozygotes in this population, if we assume that the population is in Hardy-Weinberg equilibrium?
Question 4 options:
0.21
0.3
0.42
0.49
0.7
0.42
Which of the following is NOT an assumption of the Hardy-Weinberg principle? (warning; the concepts might be worded differently from the way they are in the textbook and slides)
Question 5 options:
Natural selection is not favouring any allele over the others at the locus in question
Random mating
The breeding population is very large
There is no ‘gene flow’ between this population and others
There are more heterozygotes than homozygotes in the population
There are more heterozygotes than homozygotes in the population
Consider an allele at a locus where there is no natural selection, in a very small population, in which its frequency is 0.5. Assume there are no mutations or gene flow. What is the theoretical probability that this allele will eventually go extinct?
Question 6 options:
Zero (0): Without natural selection the allele frequency will remain unchanged forever
A lot less than 0.5 (but more than 0)
0.5
A lot more than 0.5 (but less than 1)
The probability is 1: Given enough time all the alleles at the locus will go extinct
0.5
Which of the following best describes conditions under which we would see a dramatic increase in the rate of genetic drift in a population of animals?
Question 7 options:
When migration suddenly stops between that population and all other populations of the species
When the rate of migration suddenly increases between the population and all other populations of the species
When the size of the population suddenly drops to just a few individuals for several generations
When the size of the population increases several-fold, due to excellent reproductive success throughout the population (rather than through migration)
When the whole population moves from one geographic region to another
When the size of the population suddenly drops to just a few individuals for several generations
Consider the case where a population of wild goats includes individuals with different lengths of horns, ranging from long, to short, and everything between. Horn size is heritable. Suppose there is stabilising selection acting on horn size. From the following options, which best describes the individuals that would have the highest relative fitness on average?
Question 8 options:
Goats with long horns
Goats with short horns
Goats with mid-sized horns
Goats with either long or short horns (so goats with mid-sized horns have the lowest fitness)
All goats except those with the very shortest horns
Goats with mid-sized horns
Consider the claim (which may or not be true): “Male lions have long manes; this is because most female lions who live near several males will mate with the male with the longest mane”.
From the following choices; i) What form of selection is implied by this claim?, and ii) Could the long mane of male lions be considered an adaptation?
Question 9 options:
i) Artificial selection; ii) Yes
i) Intersexual selection; ii) No
i) Intersexual selection; ii) Yes
i) Intrasexual selection; ii) No
i) Intrasexual selection; ii) Yes
i) Intersexual selection; ii) Yes
When considering what distinguishes biological species, and the origin of species, which of the following reproductive barriers (= barriers to gene flow) is a pre-zygotic barrier?
Question 1 options:
Hybrid infertility (reduced hybrid fertility)
Mechanical isolation
Temporal isolation
A and C
B and C
B and C
A population of a fish species is separated into two populations when the large lake it inhabits becomes divided into two separate lakes by falling water levels. Over thousands of years the two populations evolve independently (with no gene flow between them). The two lakes then become connected again to form one large lake, and the fish mix throughout the lake.
After this time the two populations interbreed quite often, but the offspring from the mixed matings are very prone to disease, and never survive to reproductive age.
Assuming we are following the biological species concept, which of the following pairs of terms best describes this scenario?
Question 2 options:
Allopatric speciation; Habitat isolation
Allopatric speciation; Hybrid inviability
Habitat isolation; Sympatric speciation
Habitat isolation; Hybrid inviability
Hybrid inviability; Sympatric speciation
Allopatric speciation; Hybrid inviability
After 100 years a scientist returns to the lake described in the previous question, and finds that interbreeding between the two populations is now very rare. They encounter each other often, and still breed at the same time of year. However, the courtship rituals of the males of the two populations are different, and females from Population 1 do not respond to the courtship rituals of the males of Population 2 (and the opposite is true too - females from Population 2 do not respond to the courtship rituals of the males of Population 1).
Which of the following pairs of terms best describes this new development?
Question 3 options:
Behavioural isolation; Post-zygotic Barrier
Behavioural isolation; Reinforcement
Gametic isolation; Post-zygotic barrier
Gametic isolation; Reinforcement
Post-zygotic barrier; Reinforcement
Behavioural isolation; Reinforcement
Which of the following intervals of geological time began most recently?
Question 1 options:
Cretaceous
Mesozoic
Paleozoic
Permian
Phanerozoic
Cretaceous
Which of the following is NOT correct?
Question 2 options:
Many geological periods ended with mass-extinction events.
Mass extinction events are usually caused by adaptive radiation.
The end-Permian event was the most severe mass extinction in the last 500 million years.
The Mesozoic Era ended with a mass-extinction event.
There was a major mass extinction event roughly 250 million years ago.
Mass extinction events are usually caused by adaptive radiation.
Which of the following is correct?
Question 3 options:
Adaptive evolution always proceeds ‘gradually’, through many very small changes in populations following one after the other.
An ‘exaptation’ is an adaptation that gradually increases in complexity over a very long time, during which it had a single specific function.
Complex organs have no function until the final, most complex version evolves.
‘Homeotic genes’ is the name given to new genes that arise when an identical copy of a stretch of DNA gets incorporated into a chromosome.
None of the above are correct.
None of the above are correct.
When two genes are ‘paralogs’, what does this mean? (pick the best answer)
Question 4 options:
They are next to one another on a chromosome
They are two different alleles at the same locus but neither is dominant
They are unrelated genes with identical functions
They arose through duplication of an ancestral gene
They perform similar functions but one was acquired by horizontal gene transfer
They arose through duplication of an ancestral gene
Which of the following best describes where ‘peptidoglycan’ is found?
Question 5 options:
In the nucleus of a ‘protist’
Surrounding the plasma membrane (cell membrane) of an archaeon (= member of the ‘domain’ Archaea)
Surrounding the plasma membrane (cell membrane) of a bacterium
Within the plasma membrane (cell membrane) of an archaeon (= member of the ‘domain’ Archaea)
Within the plasma membrane (cell membrane) of a bacterium
Surrounding the plasma membrane (cell membrane) of a bacterium
Which of the following features is shared by Archaea and eukaryotes?
Question 6 options:
Branched-chain membrane lipids
Organelles of endosymbiotic origin
Peptidoglycan cell walls
All of A, B and C
None of the above (A-D are all NOT correct)
None of the above (A-D are all NOT correct)
Which of the following best describes the genome of a plastid (chloroplast)?
Question 7 options:
The highly reduced genome of a cyanobacterium
The highly reduced genome of a proteobacterium
The highly reduced genome of a spirochete
The highly reduced genome of an archaeon
The highly reduced genome of a eukaryote
The highly reduced genome of a cyanobacterium
