Practice Quizzes Part 1 Flashcards
As a population geneticist, you find a species of snails with more genetic diversity than humans. What does this mean?
There is more variety in the gene pool of snails than humans
From an evolutionary perspective, germ-line mutations are more significant than somatic mutations. This is because:
Somatic mutations affect only one or a few cells and only germ-line mutations will appear in an individual’s descendants
What is the result of a mutation that occurs in somatic cells?
The mutation may be expressed in the individual, but will not be passed along to its offspring
Why is genetic variation critical for evolution?
It is the source material for natural selection
Female starlings that lay clutches of four or five eggs have more surviving young than those with either larger or smaller clutches. This is an example of:
(A) genetic drift acting on clutch size
(B) directional selection acting on clutch size
(C) disruptive selection acting on clutch size
(D) stabilizing selection acting on clutch size
(D)
A particular gene in a given population of individuals has 2 alleles, A and a. The frequency of the A allele equals the frequency of the a allele. What are the expected genotype frequencies, assuming the population is in Hardy-Weinberg equilibrium?
AA=0.25
Aa=0.5
Aa=0.25
Using visual observation of phenotype to identify allele frequency rarely works because:
Multiple genes may control phenotype
Which of these 5 evolutionary forces is rare and usually not considered by population genetics?
- Non random mating
- Mutation
- Selection
- Immigration
- Genetic drift
Mutation
All the alleles present in all individuals in a species are referred to as the WHAT of that species?
Gene pool
If an assumption for the Hardy-Weinberg equation is violated, what does this mean?
(A) The allele frequencies or genotype frequencies are undergoing evolutionary change
(B) The population is adapted to its environment
(C) Mutations are increasing in frequency in the population
(D) An allele is fixed in the population
(A)
What term correctly describes change in allele frequency due to random effect of a small population?
- Immigration
- Selection
- Non random mating
- Genetic drift
- Mutation
- Genetic drift
Genetic variation in a population refers to…
Multiple alleles within a gene pool
In a hypothetical population for 1000 frogs there exists a gene with 2 alleles. 280 of the frogs are homozygous dominant (DD), and 220 are homozygous recessive (dd). What is the frequency of heterozygous in the population?
0.50
In genetics, two organisms are part of the same population if:
They are the same species and are in the same geographic area
What does the term 2pq represent in the Hardy-Weinberg relation?
The frequency of heterozygous
The differential success of alleles is called:
Selection
What does it mean to say that an allele is “fixed” in the population?
It is an indication of no genetic variation at that locus in the population
Genetic variation has two sources-mutation and:
Recombination
At the genetic level, evolution is:
A change in the frequency of an allele or genotype over time
The Hardy-Weinberg equilibrium has 5 conditions, what are they?
- A large breeding population
- Random mating
- No change in allele frequency due to mutation
- No immigration/emigration
- No natural selection
What are the 2 equations of Hardy-Weinberg equilibrium?
P + q = 1 P^2 + 2pq + q^2 =1 P=frequency of dominant allele Q=frequency of recessive allele P^2= frequency of homozygous dominant 2pq= frequency of heterozygous genotype Q^2= frequency of homozygous recessive
Ring species such as the greenish warbler complicate the biological species concept because:
At least some of their populations are reproductively isolated from one another but can still exchange genetic material
In some large groups of plants, including dandelions, oaks, and willows, the biological species concept is complicated because the process of WHAT allows gene flow to occur between good WHAT that can be Ashly distinguished based on appearance
- Hybridization; morphospecies
- Polyploidy; ring species
- Polyploidy; evolutionary species
- Hybridization; ecological species
- Allopathic speciation; ring species
- Hybridization; morphospecies
Unlike the biological species concept, the morphospecies concept relies on:
Phenotype
Which of the following species concepts might differentiate species on the basis of specific dietary requirements?
- Evolutionary species
- Ring species
- Ecological species
- Ecological species
All members of a species can in principal mate with members of the same species but of the different sex. Two populations would not be considered part of the same species if they do not actively breed (even if they potentially could)
TRUE OR FALSE?
FALSE
Horses and donkeys can interbreed, but their offspring (mules) are infertile. This is an example of what kind of reproductive isolating mechanism?
Post-zygotes, genetic incompatibility
Male birds of different species sing species-specific songs to attract mates. Females only mate with males that sing their specific song. This is an example of:
Pre-zygotes isolation
New species can form through allopathic or sympathetic speciation. Which of the following mechanisms will act more strongly on populations that are initially separated in allopathy than those initially separated in sympathy? (A) disruptive selection (B) reinforcement (C) Temporal isolation (D) Pre-zygotes isolation
(D) Pre-zygotes isolation
The longer 2 species have been separated, the greater the number of genetic differences between them?
TRUE OR FALSE?
TRUE
Is the following a representation of genetic incompatibility?
Two groups of snakes do not produce offspring because they have a different number of chromosomes
YES OR NO?
YES
In general, sympatric speciation require the action of WHAT selection acting against hybrids?
Disruptive
Two species of antelope ground squirrels are separated by the Grand Canyon. They are hypothesized to descend from a common ancestor, populations of which were separated as the canyon formed. If this hypothesis is correct, it would be an example of:
Allopathic speciation by variance
WHAT is a special case of explosive speciation in which new species form rapidly in response to numerous "open" ecological niches? (A) Allopatric speciation (B) Adaptive radiation (C) Peripatric speciation (D) Sympatric speciation (E) Co-speciation
(B) Adaptive radiation
If an organism has 4 copies of each chromosome, then it is:
Tetraploid
Imagine a scenario in which a common population of animals is separated into 2 groups by a natural event. Over-time, you might expect the 2 populations to become WHAT genetically similar. This process is known as WHAT speciation.
- More; sympatric
- More; allopatric
- Less; sympatric
- Less; allopatric
- Less; allopatric
When 2 populations have undergone divergence in allopathy long enough to be unable to produce fertile offspring, then they are different enough to be considered different species?
TRUE OR FALSE?
TRUE
Speciation can occur in the absence of natural selection; for example, in speciation that results from instances of genetic drift
TRUE OR FALSE?
TRUE
The process by which sympatric speciation might occur would most likely be the result of:
Natural selection
Define sympatric speciation
Evolution of a new species from a surviving ancestral species while bothe continue to inhabit the same geographical region
Define allopatric speciation
2 types
When biological populations of the same species become isolated from rather to an extent that prevents/interferes with gene flow
Dispersal: in which some individuals colonize a distinct place such as an island far away from the main source population
Vicariance: in which a geographic barrier arises within a single population, separating it into 2+ island populations
Define peripatric speciation
A new species is formed from an isolated peripheral population
Difficult to distinguish from allopatric
The specific types of homologies used to develop phylogenetic are shared derived characters or:
Synapomorphies
Why is the fossil record not a complete catalog of biological history?
Not all organisms fossilize with equal probability
The Burgess Shale preserves a remarkable fossil record of:
Marine life during initial diversification of animals in the Cambrian Period (505 million years ago)
In a phylogenetic tree, a node or branching point represents:
The common ancestor from which the descendent species diverged
Organisms in the same family will be all from the same genus
TRUE OR FALSE?
FALSE
Which of the following best describes the purpose of phylogenies?
- Phylogenetics names species, genus, rider, class, phylum, and kingdom
- Phylogenetics compares anatomical or molecular features
- Phylogenetics looks for patterns in relatedness
- Phylogenetics looks for patterns of relatedness and compares anatomical or molecular features
4.
Imagine you are chatting with 1 of your friends. He states that reptiles are obviously a monophyletic group, as this group contains all of the organisms (outside fish) that posses scales. This statement is:
False; as reptiles are a paraphyletic group; this group does not include birds, even through birds share a common ancestor
The tips of the branches on a phylogenetic tree represent:
Present-day groups or extinct taxa
Characters that are similar because of descent from a common ancestor are WHAT; character that are similar due to convergent evolution are WHAT?
Homologous; analogous
When selecting among multiple possible phylogenetic trees that fit our date, we commonly use the principal of _________, which means we choose the ________ possible hypothesis. In phylogenetic analysis, that means selecting the tree that represents the __________ evolutionary changes or mutations.
Parsimony; simplest; fewest
The extinction of the _________, during the end of the Cretaceous mass extinction allowed mammals to diversify through the process of _________.
Dinosaurs; adaptive radiation
To which superkingdom does the organism that causes amoebic dysentery belong?
Amoebozoa
Green algae are most closely related to:
Land plants
What superkingdom do corn and wheat belong to?
Archaeplastida
The genes in chloroplasts more closely match the genes found in cyanobacteria compared to the genes found in the nuclei of photosynthetic eukaryotes.
TURE OR FALSE?
TRUE
Why haven’t more groups within the archaeplastids developed multicellularity?
Evolution is not goal-oriented toward producing an end product with complex multicellularity; each group is successful with its current morphology
Imagine that a researcher discovers a new type of organelle in single-called eukaryotes. She suspects this new organelle is the result of endosymbiosis. How could she support this theory?
- Use electron microscopy to determine if any structural similarities exist between this new organelle and prokaryotic cells
- determine whether this organelle has both an inner and outer membrane
- if it has its own DNA, compare its genetic sequence
Which is a human’s closest relative?
- Apple tree
- Malaria parasite
- Slime mold
- Mushroom
- Mushrooms
Which of the following explains why photosynthesis is widely but discontinuously distributed throughout the eukaryotic tree?
(A) Photosynthesis was acquired early in evolution, but then lost
(B) All eukaryotes are capable of photosynthesis, but it is repressed in some cases
(C) Some eukaryotes evolved photosynthetic pathways separate from chloroplasts
(D) Photosynthesis was acquired multiple times through endosymbiosis
(D) Photosynthesis was acquired multiple times through endosymbiosis
To which superkingdom does the organism that causes red tide belong?
Alveolata
In plasmodia slime moods, what structure is responsible for producing the haploid cells that disperse into the environment?
Sporangium
In which group of archaeplastids are the chloroplasts most similar to those of the ancestral cyanobacteria endosymbiont?
Glaucocystophytes
Chanoflagellates are the closest protistan relatives of animals.
TRUE OR FALSE?
TRUE
Evidence that supports chloroplast origins from photosynthetic bacteria includes:
- similar organization of photosynthetic membranes
- the use of 2 linked photosystems to capture electrons from water
- similarities in the DNA sequence of the chloroplast chromosomes and bacterial chromosomes
Which of the superkingdom contains at least one member that is heterotrophic, one that has cilia and one that is parasitic?
Alveolates
Some slime moods make structures called plasmodia that:
Contain many nuclei in one large cell
There are 2 competing theories put forth to explain the origin of eukaryotic cells. Name one
Ancient eukaryotic cells resembling archaea cells acquired symbiotic bacteria that eventually took up permanent residence to become mitochondria
Chloroplasts are thought to have evolved from cyanobacteria. Which of the following supports this hypothesis?
(A) They both have cell walls
(B) They both have small circular DNA genomes
(C) They both have similar internal membranes that organize the light reactions of photosynthesis
(D) They both have the capability of movement through flagella
(E) B and C
(F) A and B
(E) B and C
Why do mitochondria and chloroplasts have small genomes?
Because over time, much of their DNA has migrated to the host cell nucleus
The most diverse eukaryotic superkingdom is:
Opisthokonta
Animals, chanoflagellaates, and fungi are all part of what superkingdom?
Opisthokonts
Slime moods, entamoeba, flatbellinea, and Tubulinea are all part of what superkingdom?
Amoebozoans
Glaucocystophytes, red algae, and green algae (land plants) are all part of what superkingdom?
Archaeplastids
Diatoms, brown algae, and oomycetes are all part of what superkingdom?
Stramenopiles
Dinoflagellates, apicomplexans, and ciliates are all part of what superkingdom?
Alveolates
Cercozoans, foraminifera, radiolaria are all part of what superkingdom?
Rhizarians
Eugenics, trypanosomes, diplomonads, parabasalids are all part of what superkingdom?
Excavates
Which of the following statements about complex multicellular organisms are FALSE?
- When compared to their simpler phylogenetic relatives, complex multicellular organisms show greater species diversity
- Large differences in the body forms of complex organisms result from different patterns of gene expression
- Complex multicellular organisms and simpler multicellular organisms perform a similar range of ecological function
- Regulatory genes guide the development of complex multicellular organisms
- Complex multicellular organisms and simpler multicellular organisms perform a similar range of ecological function
Which of the following explains why bulk flow allows an organism to attain a larger body size?
- Bulk flow allows waste products to be removed more efficiently
- Black flow allows oxygen to reach interior cells that are located far from the surface of the body
- All these choices are correct
- Black flow allows rapid communication between different parts of the body
- Bulk flow allows nutrients to be transported over greater distances
- All these choices are correct
Imagine a hypothetical habitat where there are many simple and complex multicellular organisms of roughly the same size. A new predator is introduced into the habitat that feeds by taking bites of the organism but never consuming the whole thing. Explain the most likely situation.
Complex multicellular organisms will suffer more because vital differentiated cells that the rest of the organism requires will be lost
Hormones released by endocrine glands function as signal molecules.
TRUE OR FALSE?
TRUE
A researcher is looking through a microscope at a petri dish full of mouse embryos. These embryos appear as balls with no indentations along the surfaces. These embryos are most likely:
Mouse blastula
In which order where the key features of complex multicellularity likely to have appeared?
Cell adhesion
Cell communication
Regulated growth/development
What is the anatomy of a coenocytic organism?
The body is made of a large cell with many nuclei
Gastrulation in animal cells is able to take place because:
Animal cells do not have cell walls
Cells in the interior of complex multicellular organisms are able to respond to environmental signals through:
Receptors for signals sent from exterior cells that relay information about environmental changes
Which of the following is characteristic of complex multicellularity?
(A) Interior cells are exposed to a different physical and chemical environment than exterior cells
(B) All cells are exposed to an exterior surface
(C) All cells of complex multicellular organisms express the same genes
(D) The interior cells are more tolerant to lower oxygen levels than exterior cells
(A) Interior cells are exposed to a different physical and chemical environment than exterior cells
The evolution from simple multicellular organisms to complex multicellular organisms required:
The development of a system that enabled bulk flow
During animal development, a fertilized egg divides to form a ball of undifferentiated cells called a:
Blastula
Organisms that are dependent on oxygen fro cellular respiration depend on which of the following processes to move oxygen into cells
Simple diffusion
What was a major event that led to the appearance of large complex animals on Earth?
The increase in atmospheric oxygen
What is true of plasmodesmata?
They are holes in the cell wall through which the plasma membrane and endoplasmic reticulum of adjacent cells are connected
The early evolution of land plants occurred in moist lowland habitats, then about 400 million years ago they moved to the interiors of continents. What contributed to the colonization of continental regions?
Development of vascular tissue for bulk flow
The branch of biology known as evolutionary-developmental biology is the study of:
How changes in development underpin the evolution of morphology
Most simple multicellular species belong to what group?
Algae
The mesoglea of jellyfish:
Provides structural support to the jellyfish body and would be considered metabolically inactive tissue
What characteristics are present in complex multicellular organisms but not simple multicellular organisms?
- The presence of cells that are not in direct contact with the external environment
- The presence of subsets of cells (tissues) with specialized functions
One of the hypthotheses for the relationship of sponges to all other animals shows the sponges as paraphyletic. What would this suggest about the evolution of sponges?
The ancestor of sponges gave rise to a minimum of 2 lineages, one of which was the ancestor of sponges sister to all other animals
If, as some molecular data suggest, comb-jellies turn out to be the sister group of all other animals, which of the following statements would then be considered FALSE?
(A) Triploblastic animals evolved from diploblastic ancestors
(B) Choanoflagellates are the sister group to animals
(C) Sponges eve loved their simple structure by loosing features of complex anatomy
(D) Cnidarians and comb-jellies share a common ancestor that had a gut and nervous system
(D) Cnidarians and comb-jellies share a common ancestor that had a gut and nervous system
In sponges, the cels responsible for generating water currents that facilitate gas exchange and nutrition are:
Choanocytes
Cnidarians share a common body plan that takes 2 forms. The free-floating form is called a medusa, whereas the sessile form is called a:
Polyp
In cnidarians, the mouth of both the medusa and polyp form opens into an internal __________, where __________ digestion takes place
Gastric cavity; extracellular
Describe characteristics of placozoans
- placozoans are tiny animals containing only a few thousand cells
- placozoans are simple animals, consisting of only 2 tissue layers that sand which an interior fluid layer
Sponges move huge volumes of water through their bodies every day. Although this serves the function of filter feeding for the organism, how might this also provide an “ecosystem” service (something that affects and/or benefits other organisms in their environment)?
They create small currents in their micro environment that help to circulate and clean water locally for other organisms
Cnidarians form TRUE epithelial tissue
TRUE OR FALSE>
TRUE
Cnidarians are able to capture prey with the aid of _________, harpoon-like organelles that are often tipped with neurotoxins
Nematocysts
A researcher has just discovered a new marine organism that appears very similar to jellyfish. However, on closer inspection, this organism possesses both a mouth and anal pore, ans a single set of tentacles. This animal is MOST likely a:
Comb-jelly
Cnidarians have ___________ symmetry
Radial
Which of the following is NOT a cell structure found in sponges? (A) gastric cavity (B) mesohyl (C) choanocytes (D) pore
(A) gastric cavity
Multicellularity allows sponges to:
Form a protective skin
The Ecdysozoa include:
- Annelid worms
- Molluscs
- Sea anemones
- Vertebrates
- Arthropoda
- Arthropoda
How many times did a coelom evolve in protostomes?
One
Echinoderm are unique in their:
- skeletons made of interlocking plates of calcite
- five-fold symmetry
- water vascular systems
Protostomia include:
Molluscs
Annelid worms
Arthropods
Chordate all possess: (at least during embryonic development)
- a postnatal tail
- a notochord
- a dorsal nerve cord
Annelid are characterized by:
Cylindrical segmented bodies
Extensive nervous system
Hydrostatic skeletons
Molluscs are distinguished from other animals groups by:
- toothlike radula (not present in all)
- a mantle that plays a role in breathing and excretion
The major defining characteristics of arthropods are:
- jointed appendages
- segmented bodies
- complex mouthparts
Insects and tetrapods have both diversified tremendously on land. Which convergently evolved features help to explain the evolutionary success of these 2 groups?
Jointed limbs
Protostomes include:
Ecdysozoa and Lophotrochozoa
Ecdysozoa include:
- nematoda
- tardigrada
- onychophora
- arthropoda
Lophotrochozoa include:
- Annelids
- Mollusca
- Platyhelminthes
- Rotifera
Most amphibians have an aquatic larval form with _________ and terrestrial adult form with __________.
Gills; lungs
The __________, which includes the sharks, skates, and rays are unique in possessing skeletons made of __________.
Chondrichthyes; cartilage
The Osteichthyes, or bony fish, make up about half of vertebrate species diversity. Their success is due to a combination of adaptations that include:
- mobile jaws for specialized feeding
- kidneys that allow fine regulation of water balance
Vertebrates are distinguished from other chordate by:
- well-developed vertebrae in all vertebrates
- a protective cranium in all vertebrates
All amniotic lay eggs, as exemplified by reptiles, birds, and monotremes
TRUE OR FALSE?
FALSE
The _______ and _________ are unique among living vertebrates in that they lack jaws
Hagfish; lampreys
Egg laying is a character unique to which groups of animals and their ancestors?
- Mammals
- Reptiles
- Birds
- All of the above
- All of the above
Which of the flowing is not true of mammals?
(A) they all have hair
(B) They feed their young with mammary glands
(C) They all have live births instead of laying eggs
(D) They are vertebrates
(C) They all have live births instead of laying eggs
The advantages of an amniotic egg include:
- relatively long development times supported by large yolk
- the ability to resist desiccation in dry terrestrial habitats
Vertebrates share features in common with other chordate, but also eveloved characteristis not found more widely in the Chordata. Which of the following features separates most vertebrates from other Chordate animals?
- Hair
- Paired limbs
- Notochord
- Postnatal tail
- Paired limbs
The phylum Platyhelminthes is:
Flatworms
The second phylum of Platyhelminthes are parasitic and an example is:
Tapeworms
The phylum annelida includes:
Marine annelids and leeches
They have gas exchange through gills or skin
The phylum Mollusca includes:
Gastropoda
Bivalves
Cephalopoda (squid, octopus, cuttlefish)
The phylum arthropoda includes:
Chelicerata
Crustacea
Myriapoda (millipedes/centipedes)
Hexapoda (insects)
The phylum Echinodermata includes:
Sea urchins
Sea stars
The phylum Hemichordata are a…
Sister group to Echinodermata
The phylum Acorn worms includes
~75 species of wormlike animals that move through sediment on sea floor
The phylum Pterobranchs includes:
~12 species of animals that attach to the sea floor and use tentacles to filter food from water
The Phylum Chordata includes:
Cephalochordates (no cranium/vertebrae, lack differentiated head)
Tunicates (Urochordata)-similar to sponge
Vertebrates
The phylum vertebrates includes:
Jawless fish Hagfish (Myxini) Lampreys (Cephalaspidomorphi) Chondrichthyes (Sharks, rays, chimaeras) Osteichthyes (Bony fish) Fleshy-finned fish Class Amphibian (Order Urodela-salamanders, retain tails) Class Amphibian (Order Anura-frogs/toads, lack tails) Class Amphibian (Order Apoda-caecilians-legless[secondary adaptation]) Reptiles Birds Mammals
Mammals include:
Monotremes–lay eggs, no nipples (specialized glands-excrete onto hair or indent in stomach) Ex. Platypus
Marsupials–born early in development, completes development in maternal pouch (marsupium) Ex. Koala
Eutherians–placental mammals, longer period of pregnancy complete development in utero
