Biology 1407 Exam Questions and
answers graded A+
Multicellular organisms evolved from three different ancestral lineages: stramenopiles, unikonts,
and archaeplastids. Of these, fungi and animals evolved from two different lineages of ________,
and land plants are ________. - ANS✅✅unikonts; archaeplastids
Chemoautotrophic bacteria obtain their carbon from ________ and their energy from ________. -
ANS✅✅CO2; reactions involving inorganic chemicals
Dunaliella salina is a bacterium that is able to live in aqueous solutions with such high salt
concentrations that the salt cannot fully dissolve. D. salina is an example of a(n) - ANS✅✅extreme
halophile.
________ are toxic proteins secreted by pathogenic bacteria, and ________ are toxic components of
the outer membrane of gram-negative bacteria. - ANS✅✅Exotoxins; endotoxins
Which of the following is a member of the domain Archaea? - ANS✅✅methanogens
One difference between gram-positive and gram-negative bacteria is that - ANS✅✅gram-positive
bacteria have more peptidoglycan in their cell walls.
The heterokaryotic phase of a fungal life cycle is a - ANS✅✅stage in which hyphae contain two
genetically different haploid nuclei.
Humans are an example of - ANS✅✅chemoheterotrophs
Heterotrophic eukaryotes that digest their food externally and absorb the small molecules are
referred to as - ANS✅✅fungi.
Threadlike fungal filaments are called - ANS✅✅hyphae.
The ultimate source of all new alleles is - ANS✅✅mutation.
, Structures that evolved from the same structure in a common ancestor are - ANS✅✅homologous
The process through which species not closely related may come to resemble one another if they
live in a similar environment is known as - ANS✅✅convergent evolution.
Uplift and formation of a mountain range divide a freshwater snail species into two isolated
populations. Erosion eventually lowers the mountain range and brings the two populations together
again, but when they mate, the resulting hybrids all produce sterile young. This scenario is an
example of - ANS✅✅allopatric speciation
Under the biological species concept, a species is a group of organisms that - ANS✅✅have the
potential to interbreed in nature and produce fertile offspring
Allopatric speciation is not likely to occur when - ANS✅✅several populations become isolated
from one another as drying conditions cause a large body of water to become separate, smaller
bodies of water.
Which of the following would a biologist describe as microevolution? - ANS✅✅a change in the
gene pool of a population from one generation to the next
According to this figure, which pair of organisms shares the most recent common ancestor?
The figure shows a phylogenetic tree. A common ancestor divides into two branches at node 1. One
of the branches leads to lungfishes and the other leads to node 2. It divides into two branches as
well. One of these branches leads to amphibians and the other leads to node 3. It divides into two
branches, with one of them leading to mammals and the other leading to node 4. It divides into two
branches as well, one of these branches leads to lizards and snakes and the other leads to node 5. It
divides into two branches and one of them leads to crocodiles and the other leads to node 6. It
divides into two branches which lead to ostriches and hawks, respectively. - ANS✅✅mammals and
crocodiles
Which statement best describes the mode of selection depicted in the figure? - ANS✅✅directional
selection, changing the average color of the population over time
Genetic drift resulting from a disaster that drastically reduces population size is called - ANS✅✅the
bottleneck effect.
answers graded A+
Multicellular organisms evolved from three different ancestral lineages: stramenopiles, unikonts,
and archaeplastids. Of these, fungi and animals evolved from two different lineages of ________,
and land plants are ________. - ANS✅✅unikonts; archaeplastids
Chemoautotrophic bacteria obtain their carbon from ________ and their energy from ________. -
ANS✅✅CO2; reactions involving inorganic chemicals
Dunaliella salina is a bacterium that is able to live in aqueous solutions with such high salt
concentrations that the salt cannot fully dissolve. D. salina is an example of a(n) - ANS✅✅extreme
halophile.
________ are toxic proteins secreted by pathogenic bacteria, and ________ are toxic components of
the outer membrane of gram-negative bacteria. - ANS✅✅Exotoxins; endotoxins
Which of the following is a member of the domain Archaea? - ANS✅✅methanogens
One difference between gram-positive and gram-negative bacteria is that - ANS✅✅gram-positive
bacteria have more peptidoglycan in their cell walls.
The heterokaryotic phase of a fungal life cycle is a - ANS✅✅stage in which hyphae contain two
genetically different haploid nuclei.
Humans are an example of - ANS✅✅chemoheterotrophs
Heterotrophic eukaryotes that digest their food externally and absorb the small molecules are
referred to as - ANS✅✅fungi.
Threadlike fungal filaments are called - ANS✅✅hyphae.
The ultimate source of all new alleles is - ANS✅✅mutation.
, Structures that evolved from the same structure in a common ancestor are - ANS✅✅homologous
The process through which species not closely related may come to resemble one another if they
live in a similar environment is known as - ANS✅✅convergent evolution.
Uplift and formation of a mountain range divide a freshwater snail species into two isolated
populations. Erosion eventually lowers the mountain range and brings the two populations together
again, but when they mate, the resulting hybrids all produce sterile young. This scenario is an
example of - ANS✅✅allopatric speciation
Under the biological species concept, a species is a group of organisms that - ANS✅✅have the
potential to interbreed in nature and produce fertile offspring
Allopatric speciation is not likely to occur when - ANS✅✅several populations become isolated
from one another as drying conditions cause a large body of water to become separate, smaller
bodies of water.
Which of the following would a biologist describe as microevolution? - ANS✅✅a change in the
gene pool of a population from one generation to the next
According to this figure, which pair of organisms shares the most recent common ancestor?
The figure shows a phylogenetic tree. A common ancestor divides into two branches at node 1. One
of the branches leads to lungfishes and the other leads to node 2. It divides into two branches as
well. One of these branches leads to amphibians and the other leads to node 3. It divides into two
branches, with one of them leading to mammals and the other leading to node 4. It divides into two
branches as well, one of these branches leads to lizards and snakes and the other leads to node 5. It
divides into two branches and one of them leads to crocodiles and the other leads to node 6. It
divides into two branches which lead to ostriches and hawks, respectively. - ANS✅✅mammals and
crocodiles
Which statement best describes the mode of selection depicted in the figure? - ANS✅✅directional
selection, changing the average color of the population over time
Genetic drift resulting from a disaster that drastically reduces population size is called - ANS✅✅the
bottleneck effect.
