Biodiversity quiz 1
Ignoring crossover, how many kinds of gametes can be produced by an organism with a diploid number of 8?
16
The egg (ovum) of a rabbit contains 22 chromosomes. How many chromosomes are in the somatic (body) cells of a rabbit?
44
If a diploid cell undergoes meiosis and produces two gametes with n + 1 chromosomes and two gametes with n− 1 chromosomes, what type of error occurred?
A nondisjunction error occurred in meiosis I, in which both members of a homologous pair migrated to the same pole of the cell.
When can nondisjunction occur? Choose the best answer.
All three answers are correct.
What is a nondisjunction?
An error in cell division that causes homologous chromosomes or sister chromatids to move to the same side of the dividing cell
Regarding the role of cohesin protein in maintaining cohesion between sister chromatids, which of the following statements is false?
During meiosis II, cohesion holds sister chromatids together along their lengths as the second meiotic spindle forms.
A man who can roll his tongue and a woman who cannot roll her tongue have a son who can roll his tongue (R = can roll tongue; r = can't roll tongue). The son is curious about whether his father is homozygous or heterozygous for the tongue-rolling trait. Which of the following facts would allow him to know?
His father's mother cannot roll her tongue.
Which of the following occurs in meiosis, but not mitosis?
Homologous chromosomes separate.
Which life cycle stage is found in plants but not animals?
Multicellular haploid
Which of the following is a function of mitosis in humans?
Multiplication of body cells
In a typical pea experiment, two true-breeding plants with distinct traits of a single character are called the __________, and the offspring are called the __________, which will always be __________.
P (or parental) generation; F1 (or first filial) generation; hybrid
How many genes are present in the human genome?
Tens of thousands
Which choice below is a basic difference between Mendel's particulate hypothesis and the hypothesis of blending inheritance?
The blending inheritance hypothesis, but not the particulate hypothesis, maintained that after a mating, the genetic material provided by each of the two parents is mixed in the offspring, losing its individual identity.
What kind of protection does the Genetic Information Nondiscrimination Act of 2008 provide the public with regard to the use of genetic information?
The law prohibits the use of genetic test information to deny insurance coverage or employment to individuals.
Of the following chromosomal abnormalities, which type is most likely to be viable in humans?
Trisomy
Which syndrome is characterized by the XO chromosome abnormality?
Turner syndrome
Huntington's disease is an example of a genetic disorder caused by __________.
a lethal dominant allele that afflicts an individual later in life
The F1 generation differed from the F2 in Mendel's experiments in that __________.
all of the F1 showed the dominant phenotype, but only three-fourths of the F2 did
If an organism that is homozygous dominant is crossed with a heterozygote for that trait, the offspring will be __________.
all of the dominant phenotype
An alternative version of a gene is called a(n) __________.
allele
A life cycle in which there is both a multicellular diploid form, the sporophyte, and a multicellular haploid form, the gametophyte; characteristic of plants and some algae.
alternation of generations
The life cycle called __________ in plants has two multicellular stages: the __________ and the __________.
alternation of generations; haploid gametophyte; diploid sporophyte
Somatic cells in animals differ from gametes in that somatic cells __________.
are all of the cells of the body except for the gametes and their precursors
Sister chromatids differ from nonsister chromatids in that sister chromatids __________.
are products of the S phase of the cell cycle and are two copies of one chromosome
The generation of offspring from a single parent that occurs without the fusion of gametes (by budding, division of a single cell, or division of the entire organism into two or more parts). In most cases, the offspring are genetically identical to the parent.
asexual reproduction
A clone is the product of __________.
asexual reproduction and mitosis
The X-shaped, microscopically visible region where crossing over has occurred earlier in prophase I between homologous nonsister chromatids.
chiasma
A lineage of genetically identical individuals or cells. (2)
clone
A red bull is crossed with a white cow and all of the offspring are roan, an intermediate color that is caused by the presence of both red and white hairs. This is an example of genes that are __________.
codominant
Somatic cells in humans differs from gametes in that human somatic cells __________.
contain two sets of each of the 23 chromosome types
The reciprocal exchange of genetic material between nonsister chromatids during prophase I of meiosis.
crossing over
Achondroplasia, a type of dwarfism, and Huntington's disease are examples of __________, with the exception that the Huntington's allele is __________.
dominant inherited disorders; lethal
What is the result when a diploid cell undergoes meiosis?
four haploid cells
Meiosis starts with a single diploid cell and produces
four haploid cells.
How are human mitochondria inherited?
from the mother only
A life cycle in which the only multicellular form is haploid is most typical of __________.
fungi
A haploid reproductive cell, such as an egg or sperm.
gamete
A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses).
gene
Allelic variation is an important source of __________ in a population.
genetic diversity
Differences among individuals in the composition of their genes or other DNA segments.
genetic variation
During prophase I of meiosis,
homologous chromosomes stick together in pairs.
In general, the frequency with which crossing over occurs between two linked genes depends on what?
how far apart they are on the chromosome
If a plant variety is true-breeding for a dominant trait, then __________.
if the plant were allowed to self-pollinate, all of the progeny would have the dominant trait
A cell preparing to undergo meiosis duplicates its chromosomes during
interphase
The process called __________ reduces the chromosome number by __________.
meiosis; two consecutive cell divisions
Which life cycle stage is found in plants but not animals?
multicellular haploid
The effect of the environment on a phenotype is referred to as __________.
multifactorial
Human ABO groups are best described as an example of __________.
multiple alleles
In meiosis, __________ of __________ cross over and form __________.
nonsister chromatids; homologous pairs; chiasmata
Unless the chromosomes were stained to show band patterns, a karyotype would be least likely to show which of the following?
part of chromosome turned around
A family tree that describes traits in families is called a __________.
pedigree analysis
In humans, height and skin color have continuous variation in the population because of __________.
polygenic inheritance
A chromosome created when crossing over combines DNA from two parents into a single chromosome.
recombinant chromosome
Besides the fact that pea plants have a short generation time, the key to Mendel's successful plant-breeding experiments was that pea plants usually __________.
self-pollinate
A chromosome responsible for determining the sex of an individual.
sex chromosome
A type of reproduction in which two parents give rise to offspring that have unique combinations of genes inherited from both parents via the gametes.
sexual reproduction
In people with sickle-cell disease, red blood cells break down, clump, and clog the blood vessels. The blood vessels and the broken cells accumulate in the spleen. Among other things this leads to physical weakness, heart failure, joint pain, and brain damage. Such a suite of symptoms can be explained by __________.
the pleiotropic effects of the sickle-cell allele
Mendel's law of segregation states that __________.
the two alleles for a heritable character segregate (separate from each other) during gamete formation and end up in different gametes
Somatic cells in humans contain __________ set(s) of chromosomes and are therefore termed __________.
two; diploid
At the end of mitosis, __________ daughter cells that are genetically __________ are formed, while at the end of meiosis, __________ daughter cells that are genetically __________ are formed.
two; identical; four; distinct
In Labrador retrievers, a dog that has the genotype BBee, where BB produces black-pigmented fur and ee produces yellow-pigmented fur, would have __________ fur and would exhibit __________.
yellow; epistasis
If a diploid cell undergoes meiosis and produces two gametes that are normal, and one with n − 1 chromosomes, and one with n + 1 chromosomes, what type of error occurred?
A nondisjunction error occurred in meiosis II, in which both sister chromatids of a chromosome migrated to the same pole of the cell.
What kind of cell results when a diploid and a haploid gamete fuse during fertilization?
A triploid cell
Human blood groups are governed by three alleles, A, B, and O. A and B are codominant and O is recessive to both. A man who has type B blood and a woman who has type A blood could have children of which of the following phenotypes?
A, B, AB, or O
Pea plants are tall if they have the genotype TT or Tt, and they are short if they have genotype tt. A tall plant is mated with a short plant. Which outcome below would indicate that the tall parent plant was heterozygous?
The ratio of tall offspring to short offspring is 1:1.
Which of the following statements about homologous chromosomes is correct?
They have genes for the same traits at the same loci.
Fetal cells may be removed along with fluid from the womb by a process known as __________.
amniocentesis
What results if a fragment of a chromosome breaks off and then reattaches to the original chromosome at the same place but in the reverse direction?
an inversion
Which of the following results in a situation in which the chromosome number is either 2n+1 or 2n-1 ?
aneuploidy
__________ are a group of genetically identical individuals produced by a process called __________.
clones; asexual reproduction
In addition to the ABO system, humans have other blood groups, including the MN system. Individuals who have alleles for both M and N show __________ for the M and N red blood cell surface antigens.
codominance
Darwin realized the importance of heritable variation to evolution __________.
even though he never read any of Gregor Mendel's work
The scientific study of heredity and hereditary variation.
genetics
What phenomenon occurs when a particular allele will either be expressed or silenced, depending on whether it is inherited from a male or a female?
genomic imprinting
A cell containing only one set of chromosomes (n).
haploid cell
The transmission of traits from one generation to the next.
heredity
A pair of chromosomes of the same length, centromere position, and staining pattern that possess genes for the same characters at corresponding loci. One homologous chromosome is inherited from the organism's father, the other from the mother. Also called a homologous pair.
homologous chromosomes
A pair of genetic structures carrying genes that control the same inherited characters are called __________.
homologous chromosomes
Characteristic of the bdelloid rotifer is that it __________.
is an example of an animal that has not reproduced sexually in 40 million years
The major contribution of sex to evolution is that __________.
it provides a method to increase genetic variation
A display of the chromosome pairs of a cell arranged by size and shape.
karyotype
The generation-to-generation sequence of stages in the reproductive history of an organism.
life cycle
A specific place along the length of a chromosome where a given gene is located.
locus
A modified type of cell division in sexually reproducing organisms consisting of two rounds of cell division but only one round of DNA replication. It results in cells with half the number of chromosome sets as the original cell.
meiosis
The first division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the number of chromosome sets as the original cell.
meiosis I
The second division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the number of chromosome sets as the original cell.
meiosis II
During meiosis, segments of nonsister chromatids can trade places. This recombination of maternal and paternal genetic material is a key feature of meiosis. During what phase of meiosis does recombination occur?
prophase I
The correct order of events during meiosis is
prophase I, metaphase I, anaphase I, telophase I, cytokinesis, meiosis II
The zipper-like complex that forms in meiosis occurs during __________ and is called the __________.
prophase I; synaptonemal complex
Genetic diversity requires __________.
sexual reproduction, independent assortment, crossing over between nonsister chromatids of homologous chromosomes, and random fertilization
Any cell in a multicellular organism except a sperm or egg or their precursors.
somatic cell
The pairing and physical connection of duplicated homologous chromosomes during prophase I of meiosis.
synapsis
Holds one homolog tightly to the other
synaptonemal complex
The term "true-breeding plants" means __________.
that self-pollinating plants will always produce the same trait of a particular character
In incomplete dominance, the offspring __________.
will have an appearance that's intermediate between those of the two parental types.
If the two traits that Mendel looked at in his dihybrid cross of smooth yellow peas with wrinkled green peas had been controlled by genes that were located near each other on the same chromosome, then the F2 generation __________.
would have deviated from the 9:3:3:1 phenotypic ratio that is predicted by the law of independent assortment
