Midterms and Sample Final Exam Flashcards
This cell is from a diploid mammal. Which stages of cell division are possible? The cell shows 4 chromatids being pulled by the mitotic spindle to each pole of the cell. A) Anaphase I B) Anaphase II C) Anaphase of mitosis D) a & c E) b & c
E) b & c
Which of the following statements is (are) true?
A) Once meiosis is complete, further cell division always requires fertilization and formation of a zygote
B) Homologous chromosomes first pair in metaphase I
C) Cytokinesis occurs during both telophase I and II
D) All of the above
E) b and c only
C) Cytokinesis occurs during both telophase I and II
Which feature(s) of cell division generate(s) new combinations of alleles even in the absence of mutation? A) Formation of sister chromatids B) Independent assortment of chromosomes C) Crossing over D) a and b E) b and c
E) b and c
Cells from a normal diploid plant have 16 chromatids in G2 of the cell cycle. All the pollen mother cells in one pant experience non-disjunction in meiosis I. How many chromosomes would occur in the gametes (pollen grains) produced by this plant? A) 3,4, or 5 B) 7,8, or 9 C) 3 or 5 D) 7 or 9
C) 3 or 5
Potential causes of trisomy 21 (most common aneuploidy in humans) discussed in class include \_\_\_\_\_. A) maternal age B) smoking C) low socio-economic status D) all of the above E) a and b
D) all of the above
In Phlox, blue flowers are dominant to white flowers. If two heterozygotes are crossed, what is the expected ratio of phenotypes in the offspring? A) 1 blue: 1 white B) 3 blue: 1 white C) 1 white : 3 blue D) all white E) all blue
B) 3 blue: 1 white
Mendel crossed Y/Y;R/R (yellow, round) peas with y/y;r/r (green, wrinkled) peas. The F1 were all yellow and round. The F1 were selfed to generate the F2. What proportion of the offspring would be green and round? A) 1/16 B) 3/16 C) 1/3 D) 1/9 E) 9/16
B) 3/16
Mendel crossed Y/Y;R/R (yellow, round) peas with y/y;r/r (green, wrinkled) peas. The F1 were all yellow and round. The F1 were selfed to generate the F2. What proportion of the offspring would be green and round? In the above cross, what proportion of the offspring would be heterozygous at one or both loci? A) 3/4 B) 3/8 C) 1/8 D) 1/4 E) 1/2
A) 3/4
The presence or absence of dimples is controlled by a single autosomal gene with complete dominance. John and Nasreen always prided themselves on their dimples and they are a little surprised when their first child has none. What is the probability that 3 of their next 5 children will also be without dimples? A) 0.016 B) 0.088 C) 0.176 D) 0.264 E) 0.422
B) 0.088
You are breeding Babbitts and paying attention to 4 traits, each controlled by a single independently asserting gene with 2 alleles and complete dominance. You cross a male with black hair that is silky, round ears, and a calm temperament (genotype is: B/b; S/S; R/r; c/c) with a female with brown hair that is woolly, round ears, and aggressive temperament (genotype is: b/b; s/s; R/r; C/c). What is the probability that the first offspring will be your desired phenotype of black silky hair, round ears and a calm temperament? A) 1/16 B) 3/16 C) 9/32 D) 27/64
B) 3/16
In peas, tall plants are dominant to short plants, and purple flowers are dominant to white flowers. A tall plant with white flowers was crossed to a short plant with purple flowers. The offspring had the following phenotypic ratio: 1 tall, white : 1 tall, purple : 1 short, white : 1 short, purple What are the genotypes of the parents? A) Ttpp * ttPP B) TtPp * ttpp C) TTPP * ttpp D) Ttpp * ttPp E) Ttpp * TTPp
D) Ttpp * ttPp
Red-green colour blindness in humans is recessive and X-linked. A woman with normal vision whose father was colour blind marries a man with normal vision whose father was also colour blind. What proportion of their offspring will be colourblind?
A) no females, all the males
B) no females, half the males
C) half the females, half the males
D) half the females, one quarter of the males
B) no females, half the males
What phenotypic gender would XO individual have in Drosophila and C. Elegans, assuming the normal number of autosomes? A) D: male , C: male B) D: male , C: hermaphrodite C) D: female , C: hermaphrodite D) D: female , C: male E) D: intersex , C: male
A) D: male , C: male
Which of the following organisms were described in lecture as having environmental sex determination? A) turtles B) clownfish C) Butterflies D) a and b
D) a and b
In Drosophila experiment, a mutant gene causing white eyes is X-linked recessive and a mutant gene causing short bristles is autosomal recessive. Two parents from true breeding lines are crossed. One is a white eyed, long bristled male and the other is a red eyed, short bristled female. All the F1 have red eyes and long bristles. What proportion of the F2 males will have white eyes and long bristles? A) 1/8 B)1/4 C) 1/2 D) 3/8 E) 0
D) 3/8
In birds, a dominant Z-linked gene, B, produces barred feathers, and the recessive allele, b, produces non-barred feathers. A large group of full siblings were scored for wing patterns. A half of the males and half of the females had barred feathers. How many copies of the B allele did each parent have? A) female 1, male 1 B) female 2, male 1 C) female 0, male 1 D) female 1, male 0
C) female 0, male 1
You are studying ABO blood groups in human populations. If a man of type I^A I^B marries a woman of genotype I^A i, what proportion of their offspring will be heterozygous for blood type? A) 0 B) 1/4 C) 1/2 D) 3/4
D) 3/4
The gene affecting coat colour in horses shows incomplete dominance. A cremello (cream) horse and a chestnut (brown) horse are crossed and their offspring are palomino (light brown). What ratio of phenotypes would you expect if a palomino horse mates with a chestnut horse? A) 1 chestnut : 2 palomino : 1 cremello B) 3 chestnut : 1 palomino C) 1 chestnut : 1 palomino D) 3 chestnut : 1 cremello
C) 1 chestnut : 1 palomino
You are studying the colour of wing bars in rock doves. A true breeding line with plum wing bars is crossed to a true breeding line with white wing bars. The F1 all have plum wing bars. In the F2 scores for wing bars are as follows: 898 plum : 297 blue : 403 whites. What does this ratio suggest about the inheritance of wing bars?
A) An interaction between two independently assorting loci affecting one trait
B) A new phenotype resulting from dominant allele(s) at either, but not both, of two independent loci
C) Dominant epistasis
D) Recessive epistasis
D) Recessive epistasis
In mice, dominant allele A results in pigmented hairs and allele a causes albino hairs (= no pigments, white appearance). A dominant allele at an independently assorting locus B, causes agouti pigment and allele b causes black pigment. What ratio of progeny would occur if a AaBb (agouti) mouse was mated to an albino aaBb mouse. A) 9 agouti : 3 black : 4 white B) 9 agouti : 6 black : 1 white C) 3 agouti : 1 black : 4 white D) 4 agouti : 8 black: 4 white
C) 3 agouti : 1 black : 4 white
You cross two field mice with the rare phenotype of short tails and get a 2:1 ratio of short to long tails. When you cross short and long tailed mice you get a 1:1 ratio of phenotypes. A second, independently assorting gene controls belly colour with white bellies (W) dominant to grey bellies (ww). If two Ww mice with short tails are crossed, what would be the probability of getting a mouse with a grey belly and a long tail? A) 9/16 B) 3/16 C) 1/6 D) 1/12
D) 1/12
A high proportion of Olympic gold medalists are homozygous for the recessive ns (nerves of steel) trait. When present, this trait enhances performance under pressure by a consistent margin of 10%. Unfortunately, only half of individuals with the appropriate genotype exhibit the trait. This is an example of:
A) complete penetrance and variable expressivity
B) incomplete penetrance and constant expressivity
C) complete penetrance and constant expressivity
D) incomplete penetrance and variable expressivity
B) incomplete penetrance and constant expressivity
Genes that are linked _______.
A) segregate to opposite poles during meiosis
B) assort independently during meiosis
C) do not assort independently during meiosis
D) none of the above
C) do not assort independently during meiosis
In wild bluebells, linked genes determine flower colour and leaf shape. Blue flowers (B) are dominant to pink flowers (b), and long leaves (L) are dominant to round leaves (l). A double heterozygote is crossed to a plant with pink flowers and round leaves. 1000 offspring are raised and show the following phenotypes:
Blue flowers and round leaves - 435 plants
Blue flower and long leaves - 60 plants
Pink flowers and round leaves - 60 plants
Pink flowers and long leaves - 445 plants
The frequency of recombination between these two genes is \_\_\_\_ %. A) 12 B) 6 C) 60 D) 8.8 E) 88
A) 12
In wild bluebells, linked genes determine flower colour and leaf shape. Blue flowers (B) are dominant to pink flowers (b), and long leaves (L) are dominant to round leaves (l). A double heterozygote is crossed to a plant with pink flowers and round leaves. 1000 offspring are raised and show the following phenotypes:
Blue flowers and round leaves - 435 plants
Blue flower and long leaves - 60 plants
Pink flowers and round leaves - 60 plants
Pink flowers and long leaves - 445 plants
For the above cross, what was the genotype of the double heterozygote?
A) Bl/bL
B) BL/bl
C) Bl/bl
D) You can’t tell from the information given
A) Bl/bL
You have obtained the genetic map below for four genes in Babbitt. Which pair(s) of genes are unlinked?
Genetic map: a-b-c-d
10 32 18
A) a-c and a-d
B) a-d only
C) b-d only
D) a-d and b-d
E) they are all linked
D) a-d and b-d
In a three point test cross, you observed a double crossover frequency of 0.20 between two genes for which you expected to see a double crossover frequency of 0.25. What were the Coefficient of Coincidence (COC) and the Interference? A) COC=0.2, Interference=0.8 B) COC=0.8, Interference=0.2 C) COC=0.2, Interference=0.25 D) COC=0.25, Interference=0.2
B) COC=0.8, Interference=0.2
The following phenotypes are observed following a 3 point test cross of a heterozygous corn plant. What is the order of the genes involved? \++C = 174 A++ = 21 A+C = 3 \+++ = 50 \+B+ = 2 AB+ = 178 ABC = 48 \+BC = 24 Total: 500
A) BCA
B) ABC
C) CAB
C) CAB
A diploid mammal cell shows 5 chromatids being pulled to opposite poles. What type of cell division is occurring? A) meiosis II B) mitosis C) meiosis I D) you can’t tell from this picture
A) meiosis II
Place the following events in the correct temporal sequence during growth and development in eukaryotes.
-condensation of chromosomes
-movement of chromosomes to the poles
-alignment of chromosomes in the middle of the cell
-re-formation of the nuclear envelope
-duplication of chromosomes
A) condensation, movement, alignment, duplication, envelope
B) duplication, condensation, alignment, movement, envelope
c) condensation, duplication, alignment, movement, envelope
D) envelope, condensation, alignment, movement, duplication
B) duplication, condensation, alignment, movement, envelope
If a mammalian gamete has 6 chromosomes, how many chromatids were present in a single cell at metaphase II? A) 3 B) 6 C) 12 D) 24 E) 48
C) 12
Which of the following statements is (are) true?
A) Homologous chromosomes first pair in metaphase I.
B) Sister chromatids separate in anaphase of mitosis and anaphase II.
C) Once meiosis is complete, formation of a zygote must occur before any further cell division can take place
D) a and b only
E) b and c only
B) Sister chromatids separate in anaphase of mitosis and anaphase II.
Which phase of cell division relates to Mendel’s principle of independent assortment? A) Meiosis I B) Meiosis II C) Mitosis D) both a and b
A) Meiosis I
Purple and white flowered pea plants from true-breeding lines are crossed, and all F1 plants are purple. If an F1 plant is selfed, the expected ratio of purple: white in the progeny is? A) 3 purple: 1 white B) 1 purple: 1 white C) 1 purple : 3 white D) 1 purple : 0 white
A) 3 purple: 1 white
A dolphin with the autosomal recessive trait of albinism was recently born to two normal dolphins. If the same two dolphins mate again, what is the probability that three of their next five offspring will be normal? A) 0.250 B) 0.264 C) 0.063 D) 0.088
B) 0.264
Mendel crossed Y/Y; R/R (yellow, round) peas with y/y; r/r (green, wrinkled) peas. The F1 were all yellow and round. The F1 were selfed to generate the F2. What proportion of the offspring would be yellow and wrinkled? A) 1/16 B) 3/16 C) 5/16 D) 8/16 E) 10/16
B) 3/16
Mendel crossed Y/Y; R/R (yellow, round) peas with y/y; r/r (green, wrinkled) peas. The F1 were all yellow and round. The F1 were selfed to generate the F2. What proportion of the offspring would be heterozygous at one but not both loci? A) 1/16 B) 3/16 C) 6/16 D) 8/16 E) 10/16
D) 8/16
What phenotypic gender would an XO individual have in Drosophila and C. Elegans assuming the normal number of autosomes? A) D: male, C: male B) D: male, C: hermaphrodite C) D: female, C: hermaphrodite D) D: female, C: male E) D: intersex, C: male
A) D: male, C: male
In humans, brown eyes (B) are dominant to blue eyes (b), and the ability to dance (D) and wink (W) is dominant to the lack of ability (d and w). All these genes are autosomal and independently assorting. A woman of genotype bbDdww marries a man who is BbDdWw. What is the probability that their first child will be a girl and will exhibit the dominant phenotype for all three traits? A) 3/16 B) 1/16 C) 1/32 D) 3/32
D) 3/32
