QUIZ QUESTIONS

The chromosomes line up in the center of the cell during which phase of the cell cycle?

metaphase

Scurs in cattle is an example of ________. A heterozygous female will ______ scurs.

sex-influenced inheritance, not have

The height of a cactus plant is determined by 4 QTL genes. The minimum height for a cactus is 10 cm, the maximum height is 26 cm. Every single QTL allele is worth 2cm. What is an appropriate arrangement of alleles for a height of 22 cm?

AA BB Cc Dd

The separated sister chromatids are considered independent chromosomes.

Anaphase

The sister chromatids separate and head towards opposite poles of the cell during which phase of the cell cycle?

Anaphase

You conduct a cross between heterozygous parents where you expect 9:3:3:1 phenotypic ratio in the offspring, but observe a ratio of 9:7. What explains this observation?

Epistatic interaction of the two genes

The process of crossing over occurs during which phase of meiosis?

Pachytene

The microtubules of the spindle fiber attach to the kinetochore during which phase of the cell cycle?

Prometaphase

The sister chromatids are formed during which phase of the cell cycle?

S phase

Polygenic inheritance is the transmission of a trait that is determined by ______.

two or more different genes

Epistasis is the phenomenon ________.

when one gene can mask the expression of a second gene

A male Manx cat and a female Manx cat produce kitten. What is the probability that kitten has a non-manx tail?

1/3

In a species of tree, seed color is determined by four independently assorting genes: A, B, C, D. The recessive alleles of each of these genes produce abnormal enzymes that cannot catalyze a reaction in the biosynthetic pathway for seed pigment. When both red and blue pigments are present, the seeds are purple. Trees with the genotypes AABBCCDD and AaBbCcDd were crossed. What proportion of the offspring will have purple seeds? This pigment pathway is diagrammed as follows:

100%

The white Leghorn breed of chick is homozygous for the dominant allele C (this allele is normally associated with colored feathers). However, this breed is also homozygous for the dominant allele I of an independently assorting gene that inhibits coloration of the feathers. Consequently, Leghorn chickens have white feathers. The white Wyandotte breed of chickens has neither the allele for color nor the inhibitor of color, it is therefore genotypically cc ii. What are the phenotypes and proportions expected from intercrossing the progeny of a white Leghorn hen and a white Wyandotte rooster?

3 colored: 13 white

A diploid organism that you are studying has 17 pairs of chromosomes. How many total chromosomes are found in a somatic cell from this organism? A sperm cell? An egg cell?

34;17;17

Four QTLs are involved in the size of a cat's tail. How many phenotypic classes could be observed between a cross of the following 2 cats: AA Bb cc Dd x AA bb Cc DD

4

Two genes A and B work in sequence to give rise to the tiger coat pattern (black stripes in orange) in tiger fishes. Below is the sequence of steps: white precursor---->orange---->tiger patt If the allele A= color and the allele a= albino If the B=tiger pattern and b= orange So A and B represent the functional or normal copies of the genes whereas a and b represent the non-functional or defective copies of the genes. If you cross two fishes each having the genotype Aa Bb, what is the probability that an offspring would show Tiger pattern?

9/16

By definition, a quantitative trait locus refers to:

chromosomal location of one or more genes affecting the phenotype of a quantitative trait

Which of the following statements defines a quantitative trait locus ?

chromosomal location of one or more genes affecting the phenotype of a quantitative trait

When wild-type offspring are produced from a cross between parents that both display the same recessive phenotype, this illustrates the genetic phenomenon of ________.

complementation

Several genes and the environment influence _________ traits.

complex

A temperature sensitive allele that leads to the death of an animal only with exposure to a specific range of temperatures falls into the category of:

conditional lethal alleles

When a trait does not fall into discrete categories, it is referred to as a __________ trait.

continuous

Arrange the following steps from genotype to phenotype for an individual with Huntington's disease. Please fill in the blanks with the alphabets (all lowercase) without any spaces. a. Both forms of the mRNA are translated to give: a normal form of the Huntingtin protein with a 25 consecutive Glutamine residues and an abnormal/mutant form of the Huntingtin protein with 85 consecutive Glutamine residues b. Neuronal death causes the symptoms such as dementia motor dysfunction and ultimately death c. The mutant form of the Huntingtin protein aggregates within the neurons and through various mechanisms leads to the death of neurons d. Heterozygous individual has two alleles for Huntingtin gene: one wildtype allele with 25 consecutive CAG repeats in the coding sequence and one disease allele with 85 consecutive CAG repeats in the coding sequence e. Both alleles are transcribed leading to two kinds of mRNA: the normal form with 25 CAG repeats and the mutant form with 85 CAG repeats

deacb

When one is conducting a QTL mapping experiment, which of the following criteria must be applicable to the two strains that are selected for breeding to be successful?

each strain must be highly inbred & differ with respect to a quantitative trait

Which of the following are examples of quantitative traits? (many choice, select all that apply)

heart rate in mice speed of deer number of bristles in fruit flies

Meiosis involves two-step division process. _______________ separate during a first round of cell division, called meiosis I. __________________ separate during a second round, called meiosis II.

homologue pairs, sister chromatids

The number of chromosomes in a species generally

is the same for all individuals of the species

_____________ process mixes and matches alleles of genes.

meiosis

The phenomenon where the heterozygotes have a greater reproductive success than either of the two homozygotes is referred to as:

overdominance

When one gene affects several traits, the pattern is referred to as:

pleiotropy

The chromosomes start to condense during which phase of the cell cycle?

prophase

What is a centromere?

region of the chromosome where the sister chromatids join

What is the nature of the allele that we are dealing with, if it causes death in some but not all individuals within a population?

semilethal allele

When an allele causes death in some but not all individuals within a population, the allele involved is a:

semilethal allele

When an allele is dominant in one sex and recessive in the opposite sex, the inheritance pattern is referred to as:

sex-influenced inheritance

A trait is seen only in one sex but is not seen in the opposite sex. This observation would be consistent with which one of the following inheritance patterns?

sex-limited inheritance

In colder climates, dark coloration is found only in the ears, nose and feet of the certain individuals in a population of rabbits. White coloration develops on body areas where blood flow keeps the animal warm. This is known as the Himalayan pattern of fur coloration and occurs due to an allele that encodes the tyrosinase enzyme which participates in the production of the dark pigment known as melanin. This version of the tyrosinase enzyme responsible for the Himalayan pattern must be encoded by a:

temperature-sensitive allele

What are chromosomes?

the structures within living cells that contain the genetic material

A couple has 4 offspring. Neither the father nor the mother is bald. Neither of the two daughters is bald, one of the two sons is bald. If one of the two daughters marries a non-bald man and they have a daughter, what is the chance that she will become bald as an adult?

0%

Chromosomes contain the genetic material Chromosomes are replicated and passed along from parent to offspring The nuclei of most eukaryotic cells contain chromosomes that are found in homologous pairs During meiosis, each homologue segregates into one of the two daughter nuclei Each parent contributes one set of chromosomes to its offspring. The above five statements are the basis of the ________________________.

Chromosome theory of inheritance

The nuclear membrane reforms around the chromosomes during which phase of the cell cycle?

Telophase

As genes reside on chromosomes, therefore whatever happens to chromosomes, happens to the genes as well and therefore Mendel's laws would apply both to genes as well as chromosomes.

True

Consider an organism with the genotype AA BB Cc Dd , where upper case alleles are additive alleles and lower case alleles are non-additive alleles. If you calculate typically (not specifically for polygenic inheritance) the number of types of gametes based on which gene pair it belongs to etc, you will say that it would make 2x2=4 kinds of gametes based in the number of heterozygous gene pairs. This statement is accurate. However if you want to estimate the number of types of gametes classified only on the different numbers of additive alleles, it could make gametes with as few as two additive alleles and as high as four additive alleles. So a total of three different kinds of gametes varying in the number of additive alleles are possible ( some with 2 additive, some with 3 additive and some with 4 additive alleles). Determine if the underlined statement is true or false.

True