BIOL 117 EXAM 2 HIGH-YIELD GENETICS AND
CELLULAR PROCESSES SUMMARY 2026
◉ Which of the following groups of organisms is among the most
abundant on Earth?
Answer: Bacteria
◉ Which group was not described in Woese's tree of life analysis?
Answer: Prokarya
◉ What characteristics were used to classify organisms before
Woese's tree of life analysis?
Answer: Presence of a membrane-bound nucleus
◉ True or false? Data showing that the Bacteria were the first
lineage to diverge from the common ancestor of all living organisms
suggest that the Archaea and Eukarya are more closely related to
each other than they are to the Bacteria.
Answer: True
◉ Which of the following statements about phylogenetic trees is
true?
,Answer: A paraphyletic group consists of a common ancestor and
some of its descendants.
◉ Which molecule did Carl Woese study to produce his tree of life?
Answer: Ribosomal RNA
◉ What is lateral gene transfer?
Answer: Physical transfer of a gene from a species in one lineage to a
species in another lineage.
◉ Ecologist Mauro Galetti and his colleagues measured the seed
sizes of palms in forest fragments with and without toucans. The
graphs show two of the forest populations they studied.
The data in the graphs are from two of the 22 forest fragments
studied by the researchers: 7 with toucans present, 15 with toucans
absent. Why do you think the researchers bothered to study so many
forest fragments?
Answer: Forest fragments may vary in many factors. If the
researchers compare two fragments, they may happen to get a result
that is not typical of the other fragments, by chance. By comparing
many fragments, the researchers may be confident that the trend in
their samples is a real trend in the rest of the forest.
,◉ In the 1700s and 1800s, royalty in Europe often married their
close relatives; furthermore, recessive genetic diseases such as
hemophilia showed up much more often among royals than in the
general population. Explain the likely connection.
Answer: Marrying close relatives is a form of inbreeding that would
have increased the homozygosity of recessive alleles.
◉ What organisms are most numerous on Earth?
Answer: prokaryotes
◉ Which current global health concern is caused by a protist?
Answer: Malaria
◉ A prokaryote that obtains energy and carbon as it decomposes
dead organisms is a(n) _____.
Answer: heterotroph and chemotroph
◉ Show how selection, genetic drift, gene flow, and mutation relate
to genetic variation.
Answer: 1. Mutation increases genetic variation.target 1 of 4
2. Gene flow may increase or decreasegenetic variation of a
population.target 2 of 4
3. Selection may increase, decrease or maintaingenetic variation.
, ◉ Imagine that you are given some chemoorganotrophic bacteria to
grow. What should you use as a source of energy for this type of
bacteria?
Answer: sugar
◉ To apply parsimony for constructing a phylogenetic tree, ________.
Answer: choose the tree that represents the fewest evolutionary
changes, either in DNA sequences or morphology
◉ If you were using cladistics to build a phylogenetic tree of cats,
which of the following would be the best outgroup?
Answer: wolf
◉ Biologists sometimes divide living organisms into two groups:
autotrophs and heterotrophs. These two groups differ in _____.
Answer: their mode of nutrition
◉ True or false? Gene flow can either increase or decrease the
average fitness of a population.
Answer: true
◉ Explain.
CELLULAR PROCESSES SUMMARY 2026
◉ Which of the following groups of organisms is among the most
abundant on Earth?
Answer: Bacteria
◉ Which group was not described in Woese's tree of life analysis?
Answer: Prokarya
◉ What characteristics were used to classify organisms before
Woese's tree of life analysis?
Answer: Presence of a membrane-bound nucleus
◉ True or false? Data showing that the Bacteria were the first
lineage to diverge from the common ancestor of all living organisms
suggest that the Archaea and Eukarya are more closely related to
each other than they are to the Bacteria.
Answer: True
◉ Which of the following statements about phylogenetic trees is
true?
,Answer: A paraphyletic group consists of a common ancestor and
some of its descendants.
◉ Which molecule did Carl Woese study to produce his tree of life?
Answer: Ribosomal RNA
◉ What is lateral gene transfer?
Answer: Physical transfer of a gene from a species in one lineage to a
species in another lineage.
◉ Ecologist Mauro Galetti and his colleagues measured the seed
sizes of palms in forest fragments with and without toucans. The
graphs show two of the forest populations they studied.
The data in the graphs are from two of the 22 forest fragments
studied by the researchers: 7 with toucans present, 15 with toucans
absent. Why do you think the researchers bothered to study so many
forest fragments?
Answer: Forest fragments may vary in many factors. If the
researchers compare two fragments, they may happen to get a result
that is not typical of the other fragments, by chance. By comparing
many fragments, the researchers may be confident that the trend in
their samples is a real trend in the rest of the forest.
,◉ In the 1700s and 1800s, royalty in Europe often married their
close relatives; furthermore, recessive genetic diseases such as
hemophilia showed up much more often among royals than in the
general population. Explain the likely connection.
Answer: Marrying close relatives is a form of inbreeding that would
have increased the homozygosity of recessive alleles.
◉ What organisms are most numerous on Earth?
Answer: prokaryotes
◉ Which current global health concern is caused by a protist?
Answer: Malaria
◉ A prokaryote that obtains energy and carbon as it decomposes
dead organisms is a(n) _____.
Answer: heterotroph and chemotroph
◉ Show how selection, genetic drift, gene flow, and mutation relate
to genetic variation.
Answer: 1. Mutation increases genetic variation.target 1 of 4
2. Gene flow may increase or decreasegenetic variation of a
population.target 2 of 4
3. Selection may increase, decrease or maintaingenetic variation.
, ◉ Imagine that you are given some chemoorganotrophic bacteria to
grow. What should you use as a source of energy for this type of
bacteria?
Answer: sugar
◉ To apply parsimony for constructing a phylogenetic tree, ________.
Answer: choose the tree that represents the fewest evolutionary
changes, either in DNA sequences or morphology
◉ If you were using cladistics to build a phylogenetic tree of cats,
which of the following would be the best outgroup?
Answer: wolf
◉ Biologists sometimes divide living organisms into two groups:
autotrophs and heterotrophs. These two groups differ in _____.
Answer: their mode of nutrition
◉ True or false? Gene flow can either increase or decrease the
average fitness of a population.
Answer: true
◉ Explain.
