Bio Exam 2 Flashcards
There is still some controversy among biologists about whether Neanderthals should be placed within the same species as modern humans or into a separate species of their own. Most DNA sequence data analyzed so far indicate that there was interbreeding between Neanderthals and humans; however, it appears to have been limited and mostly unidirectional (Neanderthal genes are present in Homo sapiens DNA, but there exists little to no evidence of the DNA of Homo sapiens in the small number of genomes sequenced from Neanderthal fossils. Which species concept is most applicable as a method of analysis in this example?
A. morphological
B. Phylogenetic
C. Ecological
D. Biological
Phylogenetic
You are an undergraduate student working with a graduate student in an entomology lab, and she presents you with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to help her separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use?
A. morphological
B. Phylogenetic
C. Ecological
D. Biological
Morphological
Which of the following reproductive types of isolation illustrates postzygotic barriers?
A. habitat isolation
B. temporal isolation
C. hybrid breakdown
D. mechanical isolation
Hybrid Breakdown
Rocky Mountain juniper (Juniperus scopulorum) and one-seeded juniper (J. monosperma) have overlapping ranges. If pollen grains (which contain sperm cells) from one species are unable to germinate and make pollen tubes on female ovules (which contain egg cells) of the other species, then which of these terms are applicable?
- sympatric species
- prezygotic isolation
- postzygotic isolation
- allopatric species
- habitat isolation
- reduced hybrid fertility
A. 2,4,5
B. 1 and 2
C. 2 and 4
D. 1,3,6
1 and 2
Macroevolution occurs
A. when reproductive barriers, either pre- or post-zygotic, genetically isolate species, even in the presence of some gene flow between two populations.
B. only when reproductive barriers, either pre- or post-zygotic, prevent all gene flow between two populations.
C. when species populations undergo changes in allele frequencies over time.
D. when species morphology from genetic change causes their physical similarity to drift apart.
when reproductive barriers, either pre- or post-zygotic, genetically isolate species, even in the presence of some gene flow between two populations.
Microevolution occurs
A. when species diverge.
B. when reproductive barriers, either pre- or post-zygotic, genetically isolate species to the point where they no longer interbreed to produce viable offspring.
C. only when reproductive barriers, either pre- or post-zygotic, prevent all gene flow between two populations.
D. when species populations undergo changes in allele frequencies over time.
when species populations undergo changes in allele frequencies over time.
In the ocean, on either side of the Isthmus of Panama, are 30 species of snapping shrimp; some are shallow-water species, and others are adapted to deep water. There are 15 species on the Pacific side and 15 different species on the Atlantic side. The Isthmus of Panama started rising about 10 million years ago. The oceans were completely separated by the isthmus about 3 million years ago. Why should deepwater shrimp on different sides of the isthmus have diverged from each other earlier than shallow-water shrimp?
A. Fresh water entering the ocean from the canal is both less dense and cloudier than seawater. The cloudy fresh water interferes with the ability of shallow-water shrimp to locate mating partners, which reduces the frequency of mating, thereby slowing the introduction of genetic variation.
B. They have been geographically isolated from each other for a longer time.
C. Cold temperatures, associated with deep water, have accelerated the mutation rate, resulting in faster divergence in deepwater shrimp.
D. The rise of the land bridge was accompanied by much volcanic activity. Volcanic ash contains heavy metals, which are known mutagens. Ash fall caused high levels of heavy metals in the ocean sediments underlying the deep water, resulting in accelerated mutation rates and faster divergence in deepwater shrimp.
They have been geographically isolated from each other for a longer time.
Which of the following statements is most accurate?
A. Geographic separation may result in biological barriers over time if populations of a species in the newly isolated regions undergo selective pressures that promote biological isolation and prevent successful reproduction if the species were to again come into contact later.
B. Biological reproductive barriers may prevent successful interbreeding even when geographic isolation has occurred, and two populations do not come into contact with each other.
C. Biological reproductive barriers always occur after physical separation of populations.
D. Biological reproductive barriers occur as a direct result of geographic isolation of populations.
Geographic separation may result in biological barriers over time if populations of a species in the newly isolated regions undergo selective pressures that promote biological isolation and prevent successful reproduction if the species were to again come into contact later.
Which of the following processes occurs first in order to begin speciation?
A. interruption of gene flow between two populations
B. postzygotic hybrid sterility in Drosophila
C. formation of mechanical barrier to reproduction
D. single gene change
interruption of gene flow between two populations
What is(are) the feature(s) of prokaryotes that enable(s) them to adapt so quickly (you can choose more than one)?
A. small body size on average
B. rapid proliferation, which increases chance of mutation
C. short generation time
D. genetic diversity in prokaryotes, which can possibly arise by transformation, transduction, or conjugation
E. ability to transfer advantageous alleles
short generation time
genetic diversity in prokaryotes, which can possibly arise by transformation, transduction, or conjugation
ability to transfer advantageous alleles
rapid proliferation, which increases chance of mutation
In what type of environment would you find extreme halophiles living?
A. ice
B. hot springs
C. anoxic swamps
D. very salty water
Very salty water
Which gets its energy from sunlight and its carbon from ingesting other organisms?
A. photoautotroph
B. photoheterotroph
C. chemoheterotroph
D. chemoautotroph
photoheterotroph
Which are layered rocks formed by certain prokaryotes?
A. vesicles
B. montmorillonites
C. stromatolites
D. protocells
stromatolites
Since flagella of bacteria, archaea, and eukaryotes arose independently, they are considered Fill in the blank structures.
A. symbiotic
B. divergent
C. analogous
D. homologous
analogous
How many hours would it take for a single prokaryote, dividing every 20 minutes by binary fission in a favorable environment, to produce 512 of its kind?
A. 0 hours
B. 2 hours
C. 180 hours
D. 3 hours
3 hours
