Organisms that reproduce sexually ________________________.
(a) must be haploid, unlike organisms that reproduce asexually.
(b) can reproduce only with a partner that carries the same alleles.
(c) create zygotes that are genetically identical to each othe
d
Which of the following statements is true?
(a) Another name for the fertilized egg cell is the zygote.
(b) Diploid organisms reproduce only sexually.
(c) All sexually reproducing organisms must have two copies of every
chromosome.
(d) Gametes have only on
a
Which of the following statements is false?
(a) Asexual reproduction typically gives rise to offspring that are genetically
identical.
(b) Mutations in somatic cells are passed on to individuals of the next
generation.
(c) Sexual reproduction allows for a
b
Somatic cells ___________________________.
(a) are not necessary for sexual reproduction in all eukaryotic organisms.
(b) are used to produce germ-line cells when organisms reach sexual maturity
(c) leave no progeny.
(d) do not contain sex chromosomes.
c
Which of the following statements about the benefits of sexual reproduction is
false?
(a) Sexual reproduction permits enhanced survival because the gametes that
carry alleles enhancing survival in harsh environments are used
preferentially during fertiliz
a
To reproduce sexually, an organism must create haploid __________________
cells, or __________________, from diploid cells via a specialized cell division
called __________________. During mating, the father's haploid cells, called
__________________ in a
germ, gametes, meiosis, sperm, eggs, zygote, somatic, germ
During sexual reproduction, novel mixtures of alleles are generated. This is
because ______.
(a) in all diploid species, two alleles exist for every gene.
(b) a diploid individual has two different alleles for every gene.
(c) every gamete produced by a di
d
Which of the following does not describe a situation of asexual reproduction?
(a) A bacterium multiplying by simple cell division.
(b) Using a part of a plant to create a new independent plant.
(c) Using in vitro fertilization to combine a sperm and an eg
c
Both budding yeast and the bacteria E. coli are unicellular life. Which of the
following statements explains why budding yeast can undergo sexual
reproduction while E. coli cannot.
(a) Unlike E. coli, budding yeast can alternate between a diploid state an
a
T/F: Somatic cells leave no progeny and thus, in an evolutionary sense, exist only to
help create, sustain, and propagate the germ cells.
True
Indicate whether each of the following is true for meiosis, mitosis, both, or
neither.
A. formation of a bivalent
B. genetically identical products
C. condensation of chromosomes
D. segregation of all paternal chromosomes to one cell
E. involvement of DNA
A. meiosis
B. mitosis
C. both
D. neither
E. both
The formation of a bivalent during meiosis ensures that _______.
(a) one chromatid from the mother and one chromatid from the father will
segregate together during meiosis I.
(b) all four sister chromatids remain together until the cell is ready to divide
b
Imagine meiosis in a diploid organism that only has a single chromosome. Like
most diploid organisms, it received one copy of this chromosome from each of its
parents and the two homologs are genetically distinct. If only a single
homologous recombination
d
There are organisms that go through meiosis but do not undergo recombination
when forming haploid gametes. Which of the following statements correctly
describes the gametes produced by such an organism. (Assume that these
organisms are diploid, that each
c
Meiosis is a highly specialized cell division in which several events occur in a
precisely defined order. Please order the meiotic events listed below.
1. loss of cohesins near centromeres
2. chromatid pairing
3. chromosome condensation
4. chromosome repl
4, 2, 7, 6, 3, 8, 5, 1
Starting with a single diploid cell, mitosis produces [two/four]
[identical/different] [haploid/diploid] cells, whereas meiosis yields [two/four]
[identical/different] [haploid/diploid] cells. This is accomplished in meiosis
because a single round of chro
two, identical, diploid, four, different, haploid, replication, segregation, II, I, same, chromatids, arms, homologs, centromeres, chromatids
In the absence of recombination, how many genetically different types of gamete
can an organism with five homologous chromosome pairs produce?
(a) 5
(b) 10
(c) 32
(d) 64
c
Which of the following statements most correctly describes meiosis?
(a) Meiosis involves two rounds of DNA replication followed by a single cell
division.
(b) Meiosis involves a single round of DNA replication followed by four
successive cell divisions.
(
d
A diploid cell containing 32 chromosomes will make a haploid cell containing
___ chromosomes.
(a) 8
(b) 16
(c) 30
(d) 64
b
You examine a worm that has two genders: males that produce sperm and
hermaphrodites that produce both sperm and eggs. The diploid adult has four
homologous pairs of chromosomes that undergo very little recombination. Given
a choice, the hermaphrodites pr
c
Which of the following statements about meiosis is true?
(a) During meiosis, the paternal chromosomes pair with the maternal
chromosomes before lining up at the metaphase plate.
(b) Unicellular organisms that have a haploid state undergo meiosis instead o
a
During recombination ________________________.
(a) sister chromatids undergo crossing-over with each other.
(b) chiasmata hold chromosomes together.
(c) one crossover event occurs for each pair of human chromosomes.
(d) the synaptonemal complex keeps the
b
After the first meiotic cell division ________________________.
(a) two haploid gametes are produced.
(b) cells are produced that contain the same number of chromosomes as
somatic cells.
(c) the number of chromosomes will vary depending on how the paterna
b
In some fungi, cell division during meiosis gives rise to an ordered spore sac
containing a row of four haploid spores, as shown in Figure Q19-30A. The
position of each spore within the sac reflects its relation to its neighbors; in other
words, spores th
A. Incorrect
B. Correct
C. Not a valid deduction
D. Correct
E. Incorrect
In mammals, there are two sex chromosomes, X and Y, which behave like
homologous chromosomes during meiosis. Normal males have one X
chromosome and one Y chromosome, and normal females have two X
chromosomes. Males with an extra Y chromosome (XYY) are fou
b
Which of the following would not lead to aneuploidy during meiosis?
(a) sister chromatids segregating inappropriately
(b) non-sister chromatids segregating inappropriately
(c) a reciprocal rearrangement of parts between nonhomologous
chromosomes (for exam
c
A single nondisjunction event during meiosis ___________________.
(a) will block recombination.
(b) will occur only during meiosis II.
(c) cannot occur with sex chromosomes.
(d) will involve the production of two normal gametes if it occurs during
meiosis
d
During fertilization in humans, _______________________.
(a) a wave of Ca2+ ions is released in the fertilized egg's cytoplasm.
(b) only one sperm binds to the unfertilized egg.
(c) a sperm moves in a random fashion until it encounters an egg.
(d) several
a
Do you agree or disagree with the following statement? Explain your answer.
If a diploid organism has 16 chromosomes (and thus 8 pairs of homologous
chromosomes), that organism can produce only 28
genetically different gametes.
Disagree (There are two distinct mechanisms for genetic variation in gametes. One
method, the reassortment of chromosomes during meiosis, would result in a diploid
Page 38 of 50
organism with 16 chromosomes producing 28
genetically different gametes. Howe
Which of the following statements about Mendel's experiments is false?
(a) The pea plants could undergo both cross-fertilization and self-fertilization.
(b) The true-breeding strains were homozygous for the traits that Mendel
examined.
(c) The egg can car
d
Which of the following could be considered a true-breeding strain for the seedshape
phenotype? (See Figure Q19-38.)
(a) all of the round-seeded plants produced in the F2 generation
(b) all of the wrinkle-seeded plants produced in the F2 generation
(c) all
b
If you crossed the round-seeded plants obtained in the F1 generation with a truebreeding
strain of round-seeded plants, how many wrinkle-seeded plants would
you expect to obtain in the next generation? (See Figure Q19-38.)
(a) none
(b) 25%
(c) 75%
(d) all
a
If you crossed the round-seeded plants obtained in the F1 generation with a truebreeding
strain of wrinkle-seeded plants, how many round-seeded plants would
you expect to obtain in the next generation? (See Figure Q19-38.)
(a) 25%
(b) 50%
(c) 75%
(d) 100%
b
Which of the following statements about the round-seeded pea plants obtained in
the F2 generation is false? (See Figure Q19-38.)
(a) These plants are phenotypically identical for seed shape.
(b) Two-thirds of these plants are expected to be heterozygous f
c
Which of the following statements about the experiment diagrammed in Figure
Q19-38 is true?
(a) If you crossed all the round-seeded pea plants from the F2 generation with
true-breeding wrinkle-seeded pea plants, you would get more roundseeded
pea plants i
a
Which of the following reasons was essential for Mendel to disprove the theory of
blended inheritance?
(a) The traits that Mendel examined all involved genes that did not display
linkage.
(b) The traits that Mendel examined all involved the reproductive s
d
Which of the following reasons was essential for Mendel's law of independent
assortment?
(a) All the traits that Mendel examined involved genes that did not display
linkage.
(b) Several of the phenotypes that Mendel examined involved color.
(c) Mendel obs
a
T/F: The phenotype of an organism reflects all of the alleles carried by that individual.
False (The phenotype, or the observable traits, of an organism often does not fully reflect
its genotype, or the catalog of all alleles in the chromosomes. The reason is that some
alleles are dominant (call these A) and other alleles are recessive (a). An
Gregor Mendel studied pea plants and developed some very important ideas about
how genes are inherited. These studies used plant strains that were true breeding
and always produced progeny that had the same __________________ as the
parent. These strains
phenotype, homozygous, allele, dihybrid, independent, pedigree
Loss-of-function mutations ________________________.
(a) cause the production of proteins that are active in inappropriate
circumstances.
(b) will usually show a phenotype when heterozygous.
(c) are only present in a population at barely detectable levels
d
Do you agree or disagree with the following statement? Explain your answer.
A trait that is found at a low frequency in the population has to be a recessive
trait
Disagree (The frequency of a trait in a population has nothing to do with its dominance or
recessiveness. To test dominance or recessiveness, the segregation of this trait must be
observed. For example, the defective version of the gene involved in Huntin
Haplotype blocks can be seen in humans because _______.
(a) disease genes are found in haplotype blocks.
(b) modern humans descended from a relatively small population of about
10,000 individuals that existed about two thousand generations ago.
(c) some o
b
The single-nucleotide polymorphisms found in the human population
__________________.
(a) are important for genetic mapping because they represent mutations in
genes important for human disease.
(b) are rarely found among blood relatives.
(c) can be linke
c
Which of the following statements about genome-wide association studies
(GWAS) is false?
(a) GWAS use SNPs to compare populations of people with disease and
people without disease to look for SNPs more likely to be present in those
with disease.
(b) GWAS
d
Finding co-inheritance of a SNP variant and a disease tells scientists that
____________________.
(a) everybody who carries this SNP will get the disease.
(b) sequences within the SNP cause the disease.
(c) a gene important for causing the disease is link
c