Genetics Test
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?
M (metaphase)
In a flowering plant, the male part of the flower (the stamen) produces haploid microspores that divide by _____to produce sperm
spermatogenesis
Pea plants have seven different types of chromosomes. A chromosome with a centromere at the very end is called
telocentric.
Which correctly shows the flow of genetic information during gene expression?
DNA → RNA → protein
Freckles are caused by a dominant allele. A man has freckles but one of his parents does not have freckles. What is his genotype?
Heterozygous
The clerk placed two pairs of socks of black socks into one bag, what do these two pairs represent?
Homologous chromosomes
Which of the following occurs during prometaphase?
Microtubules attach to the kinetochores.
Which of the following examples of scientist and their contribution is matched incorrectly?
Morgan—polymerase chain reaction
Choose the correct match between the scientist and the field of genetics that they made the contribution to
Morgan—transmission genetics
In a cross between pure-breeding tall plants with pure-breeding short plants, all of the F1 are tall. When these plants are allowed to fertilize themselves, the F2 plants occur in a ratio of 3 tall:1 short. Which of the following is not a valid conclusion from these results?
. The tall and short traits assort independently of each other in this cross.
In animals, the inability to make the pigment melanin results in albinism, a recessive condition. Two unaffected parents, who have decided to have three children, have a first child that has albinism (genotype aa). What is the probability that the second and third children will also have albinism?
1/16
Two gene loci, A and B, assort independently, and alleles A and B are dominant over alleles a and b. What is the probability of producing an AABB zygote from a cross AaBb × AaBb?
1/16
Two gene loci, A and B, assort independently, and alleles A and B are dominant over alleles a and b. What is the probability of producing an AB gamete from an AaBb individual?
1/4
Suppose that a diploid cell contains 8 chromosomes (2n = 8). How many different combinations in the gametes are possible?
16
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
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 in a polar body cell from a rat?
21
Round seeds (R) is dominant to wrinkled seeds (r), and yellow seeds (Y) is dominant to green seeds (y). A true-breeding pea plant with round and yellow seeds is crossed to a true-breeding plant with wrinkled and green seeds. The F1 progeny are allowed to self-fertilize. What is the probability of obtaining a yellow seed in the F2?
3/4
In a cross between AABbCcDD and AaBbccdd, what proportion of the offspring would be expected to be A_B_C_D_? (A_ means AA or Aa.)
3/8
To provide food for the developing embryo, a tissue called endosperm is produced through double fertilization. Endosperm has a ploidy of
3n
Pea plants have seven different types of chromosomes. The nucleus of a megaspore in a pea ovary would contain how many chromosomes?
7
Which of the following statements is true?
A testcross can be used to determine whether an individual is homozygous or heterozygous.
Which of the following crosses would produce a 3:1 ratio of phenotypes in the next generation?
Aa x Aa
Which of the following crosses would produce a 1:1 ratio of phenotypes in the next generation?
Aa × aa
What do the two socks represent?
Sister Chromatids
Which of the following statements is true?
All of these statements are true.
Which one of the following topics belongs to a different sub discipline of genetics when compared to the rest?
Allele frequencies of certain gene in different environments
_______________ combines molecular biology and computer science.
Bioinformatics
Prokaryotic chromosomes do not have telomeres because they
are circular.
Which one of the following pairings between the sub discipline of genetics and the phenomenon is incorrect?
Chemical nature of the gene—Transmission genetics
In a germ-line cell from a female grasshopper (XX-XO sex determination system), when do the homologous X chromosomes segregate?
During meiosis I, anaphase
Genetic information can be carried in which of the following biomolecules?
Either DNA or RNA
Which of the following statements is false?
Errors in chromosome separation are rarely a problem for an organism.
__________is a change in allele frequency of a population over time.
Evolution
Which of the following statements is false?
Generally, chromosomes of eukaryotes are circular.
Gregor Mendel carried out a cross between two pea plants by taking pollen from a plant that was homozygous for round seeds and dusting the pollen onto the stigma of a plant homozygous for wrinkled seeds. Which of the following would be the reciprocal cross that Mendel had carried out for this experiment?
Homozygous round stigma pollinated with homozygous wrinkled
Which of the following would serve the least well as a model for understanding basic mechanisms of inheritance?
Humans
Which one of the following topic of research belongs to the discipline of transmission genetics?
Inheritance pattern of gene alleles
What is the role of the SRY gene in humans?
It is located on the Y chromosome and initiates the developmental pathway toward the male phenotype.
What is the expected outcome for a human embryo with the XXXY chromosome constitution?
It would likely develop into a sterile male with reduced testes.
Which of the following theories of inheritance is no longer accepted as true?
None of the above is currently considered true.
Which of the following statements is true?
None of the statements above are true.
Which of the following scientists contributed significantly to the foundations of population genetics?
Ronald Fisher
In poodles, black fur is dominant to white fur. A black poodle is crossed with a white poodle. In a litter of four, all of the puppies are black. What is the best conclusion?
The black poodle is probably homozygous.
Which of the following does NOT occur during the G2 phase of the cell cycle?
The cell divides.
Which of the following correctly describes the cell theory?
The cell is the compositional and functional unit of all life.
What might be the result if breakdown of the shugoshin protein were premature?
The separation of sister chromatids would occur prematurely.
Which of the following species is considered a model genetic organism?
The worm, Caenorhabditis elegans
Which of these are NOT prokaryotes?
Viruses
Which of the following chromosome constitutions would never lead to a viable human baby being born?
YY
The first complete DNA sequence of a non-viral, free-living organism was obtained for
a bacterium in 1995.
female with androgen-insensitivity syndrome, a sex-linked recessive condition, has
a pair of testes that produce testosterone.
In order to be functional, a eukaryotic chromosome requires all of the following except
a plasmid.
If an organism of genotype Aa is used for a test cross, what is the genotype of the other individual used in the cross?
aa
A form of a gene that has a slightly different sequence than other forms of the same gene but encodes the same type of an RNA or protein, is called a(n)
allele.
Genes come in different versions called
alleles
A measurable or observable trait or characteristic is called a
phenotype
The ability to curl one's tongue into a U-shape is a genetic trait. Curlers always have at least one curler parent but noncurlers can have one or both parents who are curlers. Using C and c to symbolize the alleles that control this trait, what is the genotype of a noncurler?
cc
The attachment point on the chromosome for spindle microtubules is the
centromere.
Within cells, genes are located on structures called
chromosomes
13. While doing field work in Madagascar, you discover a new dragonfly species that has either red (R) or clear (r) wings. Initial crosses indicate that R is dominant to r. You perform three crosses using three different sets of red-winged parents with unknown genotype and observe the following data: Cross Phenotypes 72 red-winged, 24 clear-winged 12 red-winged 96 red-winged
crosses 2 and 3
The process of splitting the cytoplasm, which separates one cell into two, is termed
cytokinesis.
The contribution of Gilbert and Sanger to modern genetics was to
develop a method for sequencing DNA.
Species in which individuals have only male or only female reproductive structures are called
dioecious.
What process is unique to plants?
double fertilization
In eukaryotes, chromosomes do not contain
ribosomes.
A change in allele frequency within a population over time leads to
evolution.
The complete genetic makeup of an organism is referred to as its
genome.
The complete genetic makeup of any organism is referred to as
genome.
Permanent, heritable changes in genetic information (DNA) are called
mutations.
The highly organized internal scaffolding of the nucleus is called the
nuclear matrix
In prokaryotes, replication usually begins at a specific place on the chromosome called the
origin of replication
Diploid cells are cells with
two sets of chromosomes.
Chromosome movement during anaphase is a result of
- the molecular motors at the kinetochores that move the chromosomes toward the poles. - shortening of the microtubules at the centrosome that pull the chromosomes toward the poles.
. A chi-square test was performed and indicated that the observed numbers of offspring were significantly different from the expected. Which of the following P-values would support this conclusion?
0.024
A couple has six daughters and is expecting a seventh child. What is the probability that this child will be a boy?
1/2
Freckles are caused by a dominant allele. A man has freckles but one of his parents does not have freckles. The man has fathered a child with a woman that does not have freckles. What is the probability that their child has freckles?
1/2
Two gene loci, A and B, assort independently, and alleles A and B are dominant over alleles a and b. What is the probability of producing an AB gamete from an AABb individual?
1/2
Pea plants have seven different types of chromosomes. A nucleus in the pea endosperm contains how many chromosomes?
21
A pollen grain that lands on a stigma grows a pollen tube to deliver ___ (how many?) sperm to the ovary. Fusion of a sperm with an egg produces a ___ n cell called a___.
2; 2; zygote
In a cross between AaBbCcDdEe and AaBbccDdee, what proportion of the offspring would be expected to be A_bbC_ddE_? (A_ means AA or Aa.)
3/256
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?
42
In Mendel's peas, yellow seeds are dominant to green. A pure-breeding yellow plant is crossed with a pure-breeding green plant. All of the offspring are yellow. If one of these yellow offspring is crossed with a green plant, what will be the expected proportion of plants with green seeds in the next generation?
50 %
Round seeds (R) is dominant to wrinkled seeds (r), and yellow seeds (Y) is dominant to green seeds (y). A true-breeding pea plant with round and yellow seeds is crossed to a true-breeding plant with wrinkled and green seeds. The F1 progeny are allowed to self-fertilize. What is the probability of obtaining a round, yellow seed in the F2?
9/16
Which of the following statements is correct?
All genomes are encoded in nucleic acids.
Identify a false statement from the descriptions of genetics below.
All human traits that display blending inheritance are affected by single gene.
The three-dimensional structure of DNA was first deciphered based on the work of
All of the above
Which of the following human genotypes is associated with Klinefelter syndrome?
All of the above
Which statement is true?
Archaea are more closely related to eukaryotes than they are to eubacteria.
Which of the following was not one of Mendel's conclusions based on his monohybrid crosses?
Genes are carried on chromosomes
Which of the following theories of inheritance is currently considered true?
Germ-plasm theory
Identify a true statement from the descriptions concerning genetics below.
Many human traits, such as skin and hair color, are determined by more than a single gene.
In which of the following organisms is gender/sex determined by the temperature during embryonic development?
Many turtles and alligators
In Mendel's peas, purple flower color is dominant to white. From which of the following descriptions can you not infer the genotype completely?
Purple
Round seeds (R) is dominant to wrinkled seeds (r), and yellow seeds (Y) is dominant to green seeds (y). A plant of unknown genotype is testcrossed to a true-breeding plant with wrinkled and green seeds. The offspring produced were 53 round and yellow, 49 round and green, 44 wrinkled and yellow, 51 wrinkled and green. What is the likely genotype of the parent in question?
RrYy
Round seeds (R) is dominant to wrinkled seeds (r), and yellow seeds (Y) is dominant to green seeds (y). A true-breeding plant with round and yellow seeds is crossed to a true-breeding plant with wrinkled and green seeds. What is the genotype of the F1 progeny?
RrYy
In species of birds, males are the homogametic sex and females the heterogametic sex. Which if the following is true in this system of sex determination?
The gender of the offspring is determined by the female parent.
In Labrador retrievers, black coat color is dominant to brown. Suppose that a black Lab is mated with a brown one and the offspring are 4 black puppies and 1 brown. What can you conclude about the genotype of the black parent?
The genotype must be Bb
Honeybees have a haplo-diploid sex determination system where females develop from a fertilized egg (they are diploid, having one allele from the female queen and one allele from the male), and males develop from unfertilized eggs (they are haploid, having only one allele from the queen). Assuming that the queen is heterozygous for a particular gene, what is the probability that a female will inherit the recessive allele from her mother? What is the probability that a male will inherit a recessive allele from his mother?
The probability that a daughter will inherit a recessive allele from her mother is 50%; the probability that a son will inherit a recessive allele from his mother is 100%.