Genetics
Which of the following is an example of heredity?
Dalmation dogs all have spots.
When cells withdraw from the continuous cell cycle and enter a "quiescent" phase, they are said to be in what stage?
G0 Phase
With which of the following would hemizygosity most likely be associated?
X-linked inheritance
Assuming independent assortment, what proportion of the offspring of the cross AaBbCcDd à AabbCCdd will have the aabbccdd genotype?
0%
In a mating between individuals with the genotypes IA IB x ii, what percentage of the offspring are expected to have the O blood type?
0%
Dentinogenesis imperfecta is a rare, autosomal, dominantly inherited disease of the teeth that occurs in about one in 8000 people. The teeth are somewhat brown in color, and the crowns wear down rapidly. Assume that a male with dentinogenesis imperfecta and no family history of the disease marries a woman with normal teeth. What is the probability that their first child will have dentinogenesis imperfecta?
1/2
Two forms of hemophilia are determined by genes on the X chromosome in humans. Assume that a phenotypically normal woman whose father had hemophilia is married to a normal man. What is the probability that their first son will have hemophilia?
1/2
Albinism, lack of pigmentation in humans, results from an autosomal recessive gene. Two parents with normal pigmentation have an albino child. What is the probability that their next child will be albino?
1/4
Albinism, lack of pigmentation in humans, results from an autosomal recessive gene (a). Two parents with normal pigmentation have an albino child. What is the probability that their next child will be an albino GIRL? Remember the product rule of probability!
1/8
Many of the color varieties of summer squash are determined by several interacting loci: AA or Aa gives white, aaBB or aaBb gives yellow, and aabb produces green. Assume that two fully heterozygous plants (AaBb x AaBb) are crossed. Give the phenotypes and frequencies of the offspring.
12 white : 1 yellow : 1 green
Drosophila melanogaster have a total diploid number of 8 chromosomes in a somatic (non-sex) cell. How many possible gamete combinations can be produced in these fruit flies?
16
The house fly, Musca domestica, has a haploid chromosome number of 6. How many chromatids should be present in a diploid, somatic, metaphase cell?
24
If a typical somatic cell has 64 chromosomes, how many chromosomes are expected in each gamete of that organism?
32
You may have heard through various media of an animal alleged to be the hybrid of a rabbit and a cat. Given that the cat (Felis domesticus) has a diploid chromosome number of 38 and a rabbit (Oryctolagus cuniculus) has a diploid chromosome number of 44, what would be the expected chromosome number in the somatic tissues of this alleged hybrid?
41
a trait in which many genes can potentially be mutated to lead to the same phenotype
50%
A recessive allele in dogs causes white spots. If two solid colored dogs are mated and produce a spotted offspring, what is the percentage chance their next puppy would be solid colored?
75%
On a pedigree chart, the following symbol would represent:
A female who is known to be heterozygous
On a pedigree chart, the following symbol would represent:
A male who is affected
What is the homunculus?
A sperm or egg containing a miniature adult, perfect in size and proportion large cyst or growth on a plant due to viral infection
If an F2 generation from a self-cross always yields offspring in a 3:1 phenotypic ratio, which of the following P crosses could have occurred?
AA x aa
Due to segregation, independent assortment and random fertilization, about how many zygote combinations are possible in humans with a total diploid number of 46 chromosomes?
About 70 trillion
The centromere position of this chromosome would be considered:
Acrocentric
Alertnative forms of a gene are called ________.
Alleles
Which of the following is TRUE about alleles?
An allele is a variant form of a gene.
The centromere of a chromosome separates during ________.
Anaphase
The accompanying figure shows a cell from an organism in which 2n = 2 and each chromosome is metacentric.
Anaphase of Meiosis II
What is the relationship between the degree of crossing over and the distance between two genes?
As the distance increases, the frequency of recombination increases.
On the pedigree chart below, the trait shown is likely inherited in what manner:
Autosomal recessive
________ is a discipline involved in the development of both hardware and software for processing, storing, and retrieving nucleotide and protein data.
Bioinformatics
How is sample size related to statistical testing?
By increasing sample size, the reliability of the statistical test increases and likelihood that the result is due to random chance decreases
Which of the following would be a gain of function allele?
Cancer caused by a mutation of the abl gene leading to overexpression of kinase enzymes
Map units used to show location of genes along a chromosome can also be called:
Centi-Morgans
The enzymes that phosphorylate the cyclin proteins that help regulate the cell cycle are called:
Cyclin-dependent kinases
The division of the cytoplasm after mitosis is called:
Cytokinesis
If a scientist changed a cell's ionic composition and complementarity between DNA strands could no long occur, what would the scientist first detect?
DNA becomes single stranded
Once the Human Genome Project was concluded, reverse genetics became a much more commonplace process, which of the following is an example of reverse genetics?
Discovering the function of the UGT2A1 and UGT2A2 genes that are linked long-term loss of smell from covid
Which of the following best describes why mapping is most accurate when genes are close together on a chromosome?
Double crossover events yield a result that looks the same as no crossover and this throws off the calculations.
What is segregation?
During gamete formation, homologlous pairs are separated to form haploid gametes.
The random formation of diploid cells happens during:
Fertilization
Linkage group
Genes on the same chromosome
Independent assortment
Genes with no linkage at all separate in this way
Which of the following is an autosomal dominant human genetic disorder?
Huntington disease
Sister Chromatids
Identical DNA copies made during S phase
Give an example of what the CRISPR-Cas9 system could be used for in biotechnology
It can be used to change some mistakes or typos for diseases.
When do segregation and independent assortment occur?
Meiosis
A certain type of congenital deafness in humans is caused by a rare autosomal recessive gene. In a mating involving a deaf man and a deaf woman, could some of the children have normal hearing?
No, since the gene in question is recessive, both of the parents are homozygous and one would not expect normal hearing in the offspring.
Phenylketonuria is an example of a _______ mutation leading to a disorder in humans
Nutritional
What is the blood type of individuals who cannot add any carbohydrate to the H substance?
O
Centromere
Point of contact between two sister chromatids where spindle fibers attach
Explain why positive interference might occur.
Positive interference might occur because of a crossover. When it occurs it decreases the probability of another one.
In studies of human genetics, usually a single individual is the reason a trait is brought ot the geneticist to create a pedigree. What term refers to this individual?
Proband
The homozygous AYAY phenotype that never shows up in offspring, where A is agouti and AY is yellow coat color is an example of a _____.
Recessive lethal allele
Parental gametes
Result of chromatids in a tetrad that do not undergo crossing over
Recombinant gametes
Result of chromatids that have exchanged parts during crossing over
Male pattern baldness is an example of a ______ mutation in humans.
Sex-influenced
Which of the following is true about the second meiotic division?
Sister chromatids disjoin and are pulled to opposite poles.
Coat color in Siamese cats is an example of a _______ mutation.
Temperature-sensitive
What occurs in the S phase of the cell cycle?
The cell synthesizes a complete copy of the DNA in its nucleus.
Explain why genes that are very far apart are more likely to have undetected crossovers occur between them.
The genes cross over at random positions in the chromosome
A null hypothesis can be best described as:
There is no real difference between the results seen and the expected outcome
Which of the following is true about sex-determining chromosomes?
They act like homologous chromosomes during meiosis so each gamete will get one sex chromosome.
What is a knock out mouse and how would it be helpful to genetics research
They are used in genetic research to see what would happen if a gene isn't there
The production of amino acids from an RNA sequence that determines the phenotype of an organism is referred to as:
Translation
Choose the true statement below.
When two genes are over 50 map units apart, a crossover would theoretically occur 100% of the time.
In pea plants, purple flowers are dominant and represented by W and white flowers are recessive and represented by w. You perform a test cross of an unknown parent that has a dominant phenotype for purple flowers. The results of F1 are 50% white and 50% purple. What is the genotype of the unknown parent?
Ww
Chiasma
X-shaped formed when chromatid arms ovelap each other
What is a heterogenous trait?
a trait in which many genes can potentially be mutated to lead to the same phenotype
Name the bases in DNA and their pairing specificities.
adenine, thymine, guanine, cytosine
At what stage of the meiotic cell cycle does crossing over occur?
after synapsis in prophase I
Where was CRISPR isolated from?
bacteria
Where are spindle fibers made in the cell?
centrosomes
Homologous chromosomes exchange parts during ____ in prophase I.
crossing over
Given the following example, which gene is located in the middle between the other two on the chromosome?
ct
In many species, there are two copies of each chromosome. In such species, the characteristic number of chromosomes is called the ________ number. It is usually symbolized as ________.
diploid; 2n
In a three-point mapping experiment, which class do you expect to find the least?
double crossover
A condition in which one gene pair masks the expression of another gene pair at a different locus is called ________.
epistasis
Meiosis II in human egg cells is completed:
fertilization
A situation in which a genetic disorder gets more severe or has earlier onset in subsequent generations would be called ________.
genetic anticipation
The diploid chromosome number of an organism is usually represented as 2n. Humans have a diploid chromosome number of 46. What would be the expected haploid chromosome number in a human?
haploid;23 chromosome
The area of our DNA that is "genetically inert" and isn' t expressed is called ______.
heterochromatin
The proteins that chromatin wraps around are called:
histone proteins
Two paired chromosomes in a 2n organism that contain similar information are called:
homologous chromosomes
What would happen if, during meiosis, the chromosome number was not halved before egg and sperm formation?
in each successive generation, the offspring would double their chromosome number
The trait of medium-sized leaves in iris plants is determined by the genetic condition PP'. Plants with large leaves are PP, whereas plants with small leaves are P'P'.What type of interaction is seen these alleles?
incomplete dominance
Assume that a cross is made between AaBb and aabb plants and that the offspring fall into approximately equal numbers of the following groups: AaBb, Aabb, aaBb, aabb. These results are consistent with which of the following?
independent assortment
A situation in which there are more than two alternative forms of a given gene like IA, IB and i would be called ________.
multiple alleles
In a three-point mapping experiment, which class do you expect to find the most?
noncrossover
When two squash plants with disc-shaped fruit are crossed, depending on the genotype of the parents, disc, sphere, and long fruits may be seen in the offspring. This is an example of ________.
novel phenotypes
The shorter arm of the chromosome is called the ____ arm.
p arm
Once a protein is made, its biochemical or structural properties play a role in producing the organism's ________.
phenotype
What is the term for a gene mutation that leads to a many of different and varied phenotypes?
pleiotropy
The phenomenon in which one crossover decreases the likelihood of crossovers in nearby regions is called ________.
positive interference
Which of the following is an example of meiosis in the body?
production of sperm cells in the testes
Recombinant DNA technology is dependent on a particular class of enzymes, known as __________ that cuts DNA at specific nucleotide sequences.
restriction enzymes
Which of the following scenarios would erroneously lead you to believe two genes reside on different chromosomes when they in fact are on the same chromosome?
the genes are very far apart on the same chromosome, such that there is always a crossover between them
Which of the following describes epigenesis?
the idea that organisms form from an undifferentiated cell that multiplies and develops into various organs
The formation of single stranded RNA from DNA is called:
transcription
What is the most prevalent form of an allele called?
wild type