Mid practice Flashcards
the longest phase during the eukaryotic cell cycle generally is
G1
Definition
“Unit of heredity”, usually described according to the way it affects the traits or characteristics of an organism
gene
Unregulated; different cell types; transcribed continually; different types
Constitutive Gene
Gene that can be turned on or off; produces proteins on a continual basis
Inducible
When Mendel crossed two plants that were heterozygous for a single trait, what was the phenotypic ratio of their offspring?
a. 1 : 2 : 1
b. 9 : 3 : 3 : 1
c. 3 : 1
d. 7 : 4
e. varied depending on the trait
c. 3 : 1
When Mendel crossed two plants that were heterozygous for a single trait, what was the phenotypic ratio of their offspring?
a. 1 : 2 : 1
b. 9 : 3 : 3 : 1
c. 3 : 1
d. 7 : 4
e. varied depending on the trait
c. 3 : 1
The likelihood that the observation variation from the expected is due to random chance is called the _____.
a. P value
b. Goodness of fit
c. degree of freedom
d. X value
e. none of the answers are correct
a. P value
A karyotype is a(n) _____.
a. organelle of eukaryotic cells
b. stage of prophase I in meiosis
c. division of the cytoplasmic material following mitosis
d. photographic representation of the chromosomes of a cell
e. non of the answers are correct
d. photographic representation of the chromosomes of a cell
During sexual reproduction, each parent contributes one set of chromosomes. Similar chromosomes from each parent are called ____.
a. karyotypes
b. sister chromatids
c. homologues
d. sex chromosomes
c. homologues
Which of the following would contain genetic material that is 100% identical?
a. homologous chromosomes
b. sister chromatids
c. X and Y chromosomes
d. all of the answers are identical
b. sister chromatids
During this phase of the cell cycle the sister chromatids are formed.
a. G1 phase
b. G2 phase
c. S phase
d. prophase
e. Cytokineses
c. S phase
What is a merozygote?
a. a zygote with a maternal effect
b. prokaryotic cell that is haploid after binary fission
c. prokaryotic cell with wild and variant types of plasmids
d. prokaryotic cell without plasmids
d. prokaryotic cell without plasmids
The centrosomes move to opposite poles of the cell
Prometaphase
The microtubules of the spindle fiber attach to the kinetochore.
nuclear membrane fragments into vesicles
kinetochore fibers capture or beginning to make contact with kinetochores at the centromeres
Prometaphase
In humans, which sex is considered to be the heterogametic sex?
Male
The process by which a geneticist can determine if a trait is on an autosome or sex chromosome is to conduct a(n):
a. reciprocal cross
b. karyotype
c. self-fertilization
d. X-linked cross
a. reciprocal cross
Genes, such as Mic2, that are found on both the X and Y chromosome are examples of _____.
a. pseudoatuosomal inheritance
b. sex-linkage
c. hemizygous inheritance
d. X-O sex determination
Pseudoautosomal inheritance
A heterozygote possesses a phenotype that is intermediate between the homozygous dominant and homozygous recessive phenotypes. This is most likely an example of _____.
a. codominance
b. incomplete dominance
c. incomplete penetrance
d. sex-influenced inheritance
Incomplete dominance
In human blood groups, the fact that an individual can have an AB blood type is an example of _____.
a. incomplete dominance
b. incomplete penetrance
c. sex-influenced trait
d. temperature-sensitive conditional allele
e. codominance
e. codominance
For a certain trait a heterozygous individual has a selective advantage than a homozygous dominant of homozygous recessive individual. This is called _______.
a. codominance
b. incomplete dominance
c. overdominance
d. incomplete penetrance
e. multiple allele systems
Overdominance
If a geneticist describes a trait as being 70% penetrant, what would they mean?
a. the expression of the trait varies by individual
b. it is lethal in 30% of the individuals who have the trait
c. only 70% of the individuals who carry the trait express the trait
d. the trait is present in 70% of the population
Only 70% of the individuals who carry the trait express the trait
If an allele is dominant in one sex, and recessive in another, it is an example of _____.
a. sex-limited inheritance
b. sex-influenced inheritance
c. incomplete dominance
d. simple Mendelian inheritance
e. incomplete dominance
Sex-influenced inheritance
Epistasis is _______.
a. another term for overdominance
b. when one gene can mask the expression of a second gene
c. a trait that is only expressed in one sex of the species
d. when two dominant alleles can be expressed the same individual
e. none of the answers are correct
When one gene can mask the expression of a second gene.
Crossing over is more likely to occur between genes that are ____ on a chromosome.
a. close together
b. far apart
far apart.
A testcross is always performed between the individual with the dominant phenotype and an individual who is _____.
a. heterozygous for the genes
b. homozygous dominant for the genes
c. homozygous recessive for the genes
d. lacking the genes
e. none of the answers are correct
homozygous recessive for the genes.
The Mic2 gene is only found on the Y chromosome, which makes it _____.
a. hemizygous
b. holandric
c. angiogenic
d. androgenic
Holandric
In the Lysis solution used to extract DNA in lab were chelators of what?
a. nucleases
b. membrane
c. DNA
d. cofactors of nucleases
e. all of the answers are correct
Cofactors of nucleases
The coat color of calico cats is a result of _____.
a. maternal inheritance
b. x-inactivation
c. imprinting
d. extranuclear inheritance
b. x-inactivation
How many Barr bodies would an individual with a XXY genotype possess?
a. o
b. 1
c. 2
d. none of the answers are correct
b. 1
Expression of ______ would inhibit X-inactivation
a. Xic
b. Xist
c. TsiX
d. all of the answers are correct
e. none of the answers are correct
c. TsiX
Inheritance patterns that obey two laws: the law of segregation and the law of independent assortment
Mendelian Inheritance
More than one wild-type allele occurring in a natural population
Genetic polymorphism
Within a population this allele will kill some individuals, but not all (not well understood)
Semilethal alleles
Phenomenon in which an allele that is expected to cause a particular phenotype does not. Described at the population level (polydactyly)
Incomplete penetrance
Term used to describe the outcome of traits is the degree to which the trait is expressed
Expressivity
Norm of reaction
Refers to the effects of environmental variation on a phenotype
In prokaryotic cells, single type of circular chromosome in a region of the cytoplasm
nucleoid
Gametes of equal size, structure and motility
Isogamous
Gametes different in size, structure, and motility
Heterogamous
Larger non-motile egg; smaller motile sperm
Oogamous
Chromosomes begin to condense and become visible with a light microscope
chromosomes begin to search nucleus for their homologue
often takes on a horse shoe shape; ends associated with proteins on nuclear lamina
Leptotene
first of five substages of prophase I in meiosis
Homologous chromosomes recognize and align themselves along their entire lengths (synapsis)
two pairs of aligned or associated sister chromatids are referred to as bivalents or tetrads
zygotene
the second stage of the prophase of meiosis
X-O system
Male XO
Female XX
Many insects
Term used to describe the single copy of an X-linked gene in males. Ex: colorblindness
Hemizygous
Sex-linked gene located on the Y chromosome (few compared to X-linked)
secondary male characteristic
Holandric genes
Short region of homology between the X and Y chromosomes some sex-linked genes have the same inheritance pattern as autosomes (males can transmit
Pseudoautosomal inheritance
when an offspring receives a combination of alleles that differs from those in the parental generation
genetic recombination
Used to predict the probability of an unordered combination of events or unspecified order
Binomial Expansion Equation
Deviation between the observed and expected outcomes
Random sampling error
What is the link between phenotype and genotype?
Proteins. determines function
Pea plants have seven different types of chromosomes. A chromosome with a centromere at the very end is called
a. submetacentric.
b. metacentric.
c. acrocentric.
d. acentric.
e. telocentric
e. telocentric
Chromosome movement during anaphase is a result of
a. disassembly of tubulin molecules by molecular motor proteins.
b. kinetochore shortening causing chromosomes to pull apart.
c. metaphasal plate splitting resulting in chromosomal disassembly.
d. the cohesion protein attaching to the centromeres of sister chromatids.
e. cilia movement inside the cellular structure.
a. disassembly of tubulin molecules by molecular motor proteins.
Which of the following occurs during prometaphase?
a. The chromosomes align in a single plane.
b. DNA is replicated.
c. Microtubules attach to the kinetochores.
d. Mitotic spindles form.
e. The two sister chromatids separate.
c. Microtubules attach to the kinetochores.
A dividing eukaryotic cell is treated with a drug that inhibits the molecular motors associated with kinetochores. At which cell cycle stage would it stop?
a. G1
b. S
c. G2
d. M (metaphase)
e. M (telophase)
d. M (metaphase)
Suppose that a diploid cell contains 8 chromosomes (2n = 8). How many different combinations in the gametes are possible?
a. 2
b. 4
c. 8
d.16
e. 64
d.16
To provide food for the developing embryo, a tissue called endosperm is produced through double fertilization. Endosperm has a ploidy of
a. 1n.
b. 2n.
c. 3n.
d. 4n.
e. 5n.
c. 3n.
What might be the result if breakdown of the shugoshin protein were premature?
a. The cohesion protein would hold the chromosome arms together longer.
b. The separation of homologous chromosomes would occur prematurely.
c. The separation of sister chromatids would occur prematurely.
d. Spindle fibers wouldn’t form.
e. Sister chromatids would never separate.
c. The separation of sister chromatids would occur prematurely.
A diploid somatic cell from a rat has a total of 42 chromosomes (2n = 42). As in humans, sex chromosomes determine sex: XX in females and XY in males. What is the total number of telomeres in a rat cell in G2?
a. 21
b. 42
c. 84
d. 126
e. 168
e. 168
A diploid somatic cell from a rat has a total of 42 chromosomes (2n = 42). As in humans, sex chromosomes determine sex: XX in females and XY in males. What is the total number of chromosomes present in the cell during metaphase I of meiosis?
a. 21
b. 42
c. 84
d. 126
e. 168
b. 42
A diploid somatic cell from a rat has a total of 42 chromosomes (2n = 42). As in humans, sex chromosomes determine sex: XX in females and XY in males. What is the total number of chromosomes in a polar body cell from a rat?
a. 21
b. 40
c. 41
d. 42
e. 84
a. 21
The first offspring from the parents are called
A. P.
B. F1.
C. F2.
D. testcross.
E. backcross.
B. F1.
Which of the following terms is not a type of mating cross?
A. reciprocal
B. testcross
C. monohybrid
D. dihybrid
E. dominant
E. dominant
A _____________ is a cross between an unknown and a homozygous recessive.
A. testcross
B. dihybrid
C. monohybrid
D. backcross
E. controlled
A. testcross
If the parents of a family already have two boys, what is the probability that the next two offspring will be
girls?
A. 1
B. 1/2
C. 1/3
D. 1/4
E. 1/8
D. 1/4
In some genetically engineered corn plants the dominant gene (BT) produces a protein that is lethal to
certain flying insect pests that eat the corn plants. It was also found that the pollen could cause death in
some flying insects. If the corn plant is heterozygous for BT, what proportion of the pollen would carry
the dominant gene?
A. all pollen
B. 1/2
C. 1/3
D. 1/4
E. 1/8
B. 1/2
Suppose that in plants, smooth seeds (S) are dominant to wrinkled seeds (s) and tall plants (T) are
dominant to short plants (t). A tall plant with smooth seeds was backcrossed to a parent that was short and
wrinkled. What proportion of the progeny is expected to be homozygous for short and wrinkled?
A. 1/2
B. 1/4
C. 1/8
D. 1/16
E. 0
B. 1/4
. Suppose that in plants, smooth seeds (S) are dominant to wrinkled seeds (s) and tall plants (T) are
dominant to short plants (t). A tall plant with smooth seeds was backcrossed to a parent that was short and
wrinkled. What proportion of the progeny is expected to be heterozygous for tall and smooth?
A. 1/2
B. 1/4
C. 1/8
D. 1/16
E. 0
B. 1/4
A rare recessive trait in a pedigree is indicated by which pattern of inheritance?
A. vertical
B. horizontal
C. diagonal
D. both vertical and horizontal
E. None of these is correct.
B. horizontal
The dominant trait, Huntington disease causes severe neural/brain damage at approximately age 40. A
female whose mother has Huntington disease marries a male whose parents are normal. It is not known
if the female has the disease. What is the probability that their firstborn will inherit the gene that causes
Huntington disease?
A. 25%
B. 50%
C. 75%
D. 100%
E. 0%
A. 25%
Among the dihybrid crosses below, which will produce a 1:1 phenotypic ratio?
A. AABB × aabb
B. AaBb × AaBb
C. AaBb × aabb
D. AaBB × aaBB
E. AAbb × aaBB
D. AaBB × aaBB
