Exam 2 Material

Question 1

Which one of the following would cause the Hardy-Weinberg principle to be inaccurate?

Answer 1

Anything that causes evolution can prevent the Hardy-Weinberg principle from accurately predicting genotype
frequencies, e.g., rgd (random genetic drift), natural selection, gene flow, nonrandom mating.

Question 2

Which of the following is least likely to help maintain allelic variation in a population?

Answer 2

directional selection

Question 3

When we begin to observe the population, the relative frequency of the homozygote dominant is 0.16, that of the
heterozygotes is 0.48, and that of the homozygote recessive is 0.36. The population contains over 100,000 individuals.
What are the allele frequencies when we begin to observe the population?

Answer 3

0.40 and 0.60

Question 4

A healthy individual is a carrier of a lethal allele but is unaffected by it. What is the probable genotype of this
individual at this locus?

Answer 4

one recessive lethal allele and one dominant normal allele

Question 5

___________ is transcribed into ____________.

Answer 5

DNA,RNA

Question 6

If an allele went to fixation in 30 generations in Staphylococus aureus, that means that

Answer 6

at a given locus, all of the individuals in a population have the same sequence AND at a given locus, all of the individuals in a population have the same allele.

Question 7

What genes were surprising when first discovered because they expressed in different body segments in the same
order as they occurred on the chromosomes?

Answer 7

Hox

Question 8

A genotype or allele that is uncommon is called what?

Answer 8

Mutant

Question 9

_________________ is different growth rates between different body parts of an individual, e.g., the lower jaw of an
embryo or fetus growing faster than its upper jaw

Answer 9

Allometry

Question 10

What type of gene seems to determine the number of vertebrae that a mouse develops and the number of full wings
that a fruit fly (Drosophila) develops?

Answer 10

Homeotic

Question 11

Which one of the following best explains why geographic isolation might not result in speciation?

Answer 11

too few genetic differences accumulated between populations before they became sympatric

Question 12

Speciation by allopolyploidy results from errors during gamete production combined with what?

Answer 12

hybridization

Question 13

By definition, when a cell divides and the 2 daughter cells are different from the parent cell in shape and other
properties, ________________ has occurred.

Answer 13

Cell differentiation

Question 14

What about auto- and allopolyploidy often leads to speciation?

Answer 14

odd numbers of chromosomes in offspring from pairings of the polyploid and the ancestral parent type(s) lead to
errors during meiosis

Question 15

A phylogenetic tree that is ʺ rooted ʺ is one

Answer 15

at whose base is located the common ancestor of all taxa depicted on that tree

Question 16

Which of the following get energy by oxidizing inorganic substances (e.g., hydrogen sulfide) and
use that energy, in part, to synthesize organic compounds from CO2?

Answer 16

Chemoautotrophs

Question 17

Rhizobium

Answer 17

lives in or on roots

Question 18

Most human pathogens prefer temperatures near that of the human body. These pathogens are
called

Answer 18

Mesophiles

Question 19

Organisms that can live only in the presence of oxygen are called

Answer 19

obligate aerobes

Question 20

Which of these statements about prokaryotes is correct?

Answer 20

Divide by binary fission

Question 21

the pillus is

Answer 21

a hollow tube through which DNA transfers to another prokaryote.

Question 22

How is genetic information stored in bacteria?

Answer 22

in a loop of DNA and 0 or more smaller bits of DNA (also often in loops), all in the cytoplasm.

Question 23

___________ is when a prokaryote acquires DNA that it did not have before, but that was left
behind after infection by a virus (by a bacteriophage).

Answer 23

Transduction

Question 24

What is it called when molecules essential to life form from nonliving, from even inorganic,
compounds, as in the Miller-Urey experiments?

Answer 24

abiotic synthesis

Question 25

Proteins are macromolecules made up of what smaller organic molecules?

Answer 25

amino acids

Question 25

Cells get grouped into __________, which get grouped into __________.

Answer 25

tissues, organs

Question 25

An area where two species interbreed is known as a(n)______________ zone

Answer 25

hyrbid

Question 26

A knockout construct is

Answer 26

an organism in which a DNA sequence of interest has been changed to examine how the
phenotype is affected.

Question 27

Speciation with geographic isolation is known as

Answer 27

allopatric speciation