BISC 202 Lecture Notes - Lecture 9: Summer Squash, Mendelian Inheritance, Corn Snake

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whiterat187

8 Oct 2017

School

Simon Fraser University

Department

Biological Sciences

Course

BISC 202

Professor

Carol Wenzel

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Document Summary

Other kinds of interactions: often the phenotypes or ratios we expect are not observed: i(cid:374)te(cid:396)a(cid:272)tio(cid:374)s (cid:271)et(cid:449)ee(cid:374) alleles of a si(cid:374)gle ge(cid:374)e- variations on dominance. Gene interactions: phe(cid:374)ot(cid:455)pes a(cid:396)e ofte(cid:374) affe(cid:272)ted (cid:271)(cid:455) (cid:373)o(cid:396)e tha(cid:374) o(cid:374)e ge(cid:374)e, i(cid:374) ge(cid:374)e i(cid:374)te(cid:396)a(cid:272)tio(cid:374), the fu(cid:374)(cid:272)tio(cid:374) of (cid:374)u(cid:373)e(cid:396)ous ge(cid:374)e p(cid:396)odu(cid:272)ts (cid:272)o(cid:374)t(cid:396)i(cid:271)utes to the de(cid:448)elop(cid:373)e(cid:374)t of a common phenotype, ge(cid:374)e p(cid:396)odu(cid:272)ts a(cid:272)t togethe(cid:396) i(cid:374) diffe(cid:396)e(cid:374)t (cid:449)a(cid:455)s. 9:3:3:1 ratio with new phenotype classes: ge(cid:374)es i(cid:374)(cid:448)ol(cid:448)ed i(cid:374) sepa(cid:396)ate pig(cid:373)e(cid:374)t path(cid:449)a(cid:455)s i(cid:374)flue(cid:374)(cid:272)e ski(cid:374) (cid:272)olou(cid:396) i(cid:374) the (cid:272)o(cid:396)(cid:374) s(cid:374)ake, wildt(cid:455)pe (cid:272)o(cid:396)(cid:374) s(cid:374)akes ha(cid:448)e a (cid:272)a(cid:373)ouflaged phe(cid:374)ot(cid:455)pe (cid:894)(cid:396)esult of s(cid:455)(cid:374)thesis of (cid:271)oth o(cid:396)a(cid:374)ge a(cid:374)d black pigments). Variant pure breeding orange (whi(cid:272)h does(cid:374)"t (cid:373)ake (cid:271)la(cid:272)k(cid:895) a(cid:374)d pu(cid:396)e (cid:271)(cid:396)eedi(cid:374)g (cid:271)la(cid:272)k (cid:894)(cid:449)hi(cid:272)h does(cid:374)"t (cid:373)ake o(cid:396)a(cid:374)ge(cid:895) st(cid:396)ai(cid:374)s e(cid:454)ist. C(cid:396)osses (cid:271)et(cid:449)ee(cid:374) the t(cid:449)o st(cid:396)ai(cid:374)s (cid:455)ield s(cid:374)akes with the wildtype camouflaged phenotype: P o+/o+; b/b x o/o; b+/b+ orange black. Camouflaged: whe(cid:374) the f(cid:1005) s(cid:374)akes a(cid:396)e i(cid:374)te(cid:396)(cid:271)(cid:396)ed the(cid:455) p(cid:396)odu(cid:272)e a (cid:374)e(cid:449) al(cid:271)i(cid:374)o phe(cid:374)ot(cid:455)pe (cid:894)i. e. (cid:374)eithe(cid:396) pig(cid:373)e(cid:374)t synthesized) in the f2, f(cid:1006) phe(cid:374)ot(cid:455)pi(cid:272) (cid:396)atio is 9:(cid:1007):(cid:1007):(cid:1005).

Related Questions

___1. Nationally, the most common cause of Down Syndrome is
a. nondisjunction of Chromosome 21 during meiosis
b. translocation of Chromosome 21 onto another chromosome
c. inversion of a large section of Chromosome 21
d. deletion of the Down Syndrome gene
___2. In humans, sex is determined by
a. The presence or absence of the Y chromosome
b. The ratio of X chromosomes to sets of autosomes
c. The temperature during fetal development
d. Which parent is stronger at the time of conception
___3. A translocation is
a. a chromosomal abnormality in which a piece of one chromosome breaks off and attaches to a different chromosome
b. an abnormality in which the chromosomes are translocated out of the nucleus
c. a condition in which the chromosome has broken in two places and come back together with the middle segment backward
d. an abnormality in which there is an extra copy of one chromosome
___ 4. In snapdragons, a red-flowered plant crossed with a white-flowered plant produces all pink-flowered offspring. But crossing two pink-flowered plants produces red, pink, and white in a 1:2:1 ratio. This is a good example of
a. Incomplete dominance
b. Dominance of the red allele over the white allele
c. Lethal effects of the pink allele
d. Sex-linkage of the flower-color alleles
___ 5. If a person with type AB blood marries a person with Type O blood, what blood types are possible in their children? (Assume this trait is a single-gene trait, not complicated by interaction with other genes).
a. A, B, AB, or O
b. A or B only
c. AB or O only
d. AB only 2
___6. In what phase of meiosis are haploid nuclei first formed? a. Anaphase I b. Metaphase II c. Telophase II d. Metaphase I e. Telophase I
___7. What is the phenotype of a heterozygous tall pea plant? a. tall b. Tt c. TT d. tt e. dominant
___ 8. If genes A and B are far apart on a chromosome, and A and C are close together, which of the following observations is expected?
a. Crossing over will occur more often between A and C than between A and B
b. Crossing over will occur at equal frequencies between A and C, and between A and B
c. Crossing over will occur more often between A and B than between A and C
___9. Sometimes an organismâs genotype for one gene masks the effect of a different gene. This phenomenon is called
a. Dominance
b. Incomplete dominance
c. Co-dominance
d. Epistasis
e. Variable expressivity
___10. The dominant allele of a gene is
a. The one that is expressed most often in a population
b. The one that is expressed most often in any particular cross
c. The one that is expressed in an individual that has two different alleles
d. The one that is most healthy to have, that gives the greatest fitness
___11. In human cells, DNA replication occurs
a. In S phase of interphase
b. In G1 phase of interphase
c. In G2 phase of interphase
d. In prophase of mitosis
e. Whenever the cell needs to read the DNA to make proteins
___ 12. A process in which recipient cells take up genes from DNA molecules floating free in the surrounding medium is called
a. conjugation
b. specialized transduction
c. generalized transduction
d. transformation 3
___ 13. Most calico cats are female. However, a few rare males are observed. What is the genotype of a male calico cat?
a. X BX 0
b. X OY
c. X BY
d. X BYY
e. X BX OY
___ 14. A type of red-green color-blindness is a sex-linked (X-linked) recessive trait in humans. Can a woman have this type of color-blindness?
a. Yes, a woman could be color-blind if her mother and father were both heterozygous.
b. Yes, a woman could be color-blind but only if she has an abnormal number of sex chromosomes.
c. No, women can't show sex-linked traits because they lack a Y chromosome.
d. No, women can't show sex-linked traits because they have two X chromosomes.
e. Yes, a woman could be color-blind if her father was color-blind and her mother was a carrier (heterozygous).

1. A species of flowering plant includes plants with blooms that range from bright golden yellow to very pale yellow; no flowers carrying the yellow pigment allele appear white. The allele for yellow flower color:

a. must be a suppressor of another allele.
b. demonstrates incomplete penetrance.
c. demonstrates variable expressivity.
d. must be a modifier of another allele.
e. demonstrates variable penetrance.

2. Coat color in mice is determined by two alleles acting at a single locus: B is dominant and results in mice with black coats, and b is recessive and results in mice with white coats. In a litter of 12 mice, nine are black (B/â) and three are white (b/b). What is the penetrance of the B coat color allele?

a. zero
b. 25 percent
c. 50 percent
d. 75 percent
e. 100 percent

3. Semisterility in nearly 50 percent of the progeny they produce is often an indication that:

a. the parents are translocation heterozygotes.
b. both parents carry pericentric inversions.
c. both parents carry polytene chromosomes.
d. one of the parents carries a chromosomal deletion that removes a telomere.
e. one of the parents carries a chromosomal deletion that removes a chromosome's centromere.

4. A researcher is studying melanoma cells derived from a patient's skin tumor. He determines that all melanoma cells are 2n + 1, but the chromosome number in all normal skin cells is 2n. The 2n + 1 melanoma cells likely arose from:

a. mitotic nondisjunction.
b. meiotic nondisjunction.
c. mitotic recombination.
d. parthenogenesis.
e. colchicine treatment.

5. Why won't a balancer chromosome in Drosophila produce viable crossover products when paired with a wild-type chromosome?

a. Balancer chromosomes contain multiple inversions.
b. Balancer chromosomes contain multiple deletions.
c. Balancer chromosomes have no centromere.
d. Balancer chromosomes have no telomeres.
e. None of the answers is correct.

6. A doctor notes that a patient's genome contains 100 potentially harmful recessive mutations; however, the patient is heterozygous for all of the loci considered and thus does not demonstrate any abnormal phenotypes. The 100 recessive mutations the doctor discovered represent the patient's:

a. bivalents.
b. monosomy.
c.genetic load.
d. amphidiploidy.
e.nondisjunction.

7.The term describing the relationship between the number of copies of a gene and how much product is made from the gene is:

gene-dosage effect.
gene balance.
dosage compensation.
transcription.
aneuploidy.

8. The gene for upright ears in rabbits has two alleles. The E allele is dominant and results in upright ears, and the recessive e allele results in droopy ears. Of 100 rabbits surveyed, 87 had a genotype for upright ears (E/â). However, only 72 of these 87 rabbits had upright ears; the remaining 15 rabbits had completely droopy ears. This suggests that the allele for upright ears:

a. has incomplete penetrance.
b. has complete penetrance.
c. demonstrates variable expressivity.
d. is lethal.
e. is incompletely dominant.

9. A researcher has selfed an autotetraploid plant with the genotype D/D/d/d, and in the resulting progeny she observes a 35:1 phenotypic ratio. What can she conclude from this observation?

a. The progeny from this cross do not demonstrate a standard Mendelian phenotypic ratio.
b. In the 35:1 phenotypic ratio, the 1 represents the phenotype of the d/d/d/d progeny.
c. During meiosis in the D/D/d/d parent plant, it is likely that only bivalents, no quadrivalents or trivalents, formed.
d. It is likely that in this plant species, gametes associate with one another randomly.
e. All of the answers are correct.

10. A researcher is studying fur color in a new species of bats. He notices that fur color, which is due to the presence of a dominant allele (G), ranges from light gray to very dark gray. In addition, some bats that carry a G allele have no fur pigmentation whatsoever; their coats appear white. This is an example of:

a. only variable expressivity.
b. only incomplete penetrance.
c. both variable expressivity and incomplete penetrance.
d. recessive allele lethality.
e. pleiotropy.

amethystdinosaur303

**Please answer ALL 10 QUESTION**

a. must be a suppressor of another allele.

b. demonstrates incomplete penetrance.

c. demonstrates variable expressivity.

d. must be a modifier of another allele.

e. demonstrates variable penetrance.

a. zero

b. 25 percent

c. 50 percent

d. 75 percent

e. 100 percent

3. Semisterility in nearly 50 percent of the progeny they produce is often an indication that:

a. the parents are translocation heterozygotes.

b. both parents carry pericentric inversions.

c. both parents carry polytene chromosomes.

d. one of the parents carries a chromosomal deletion that removes a telomere.

e. one of the parents carries a chromosomal deletion that removes a chromosome's centromere.

a. mitotic nondisjunction.

b. meiotic nondisjunction.

c. mitotic recombination.

d. parthenogenesis.

e. colchicine treatment.

5. Why won't a balancer chromosome in Drosophila produce viable crossover products when paired with a wild-type chromosome?

a. Balancer chromosomes contain multiple inversions.

b. Balancer chromosomes contain multiple deletions.

c. Balancer chromosomes have no centromere.

d. Balancer chromosomes have no telomeres.

e. None of the answers is correct.

a. bivalents.

b. monosomy.

c.genetic load.

d. amphidiploidy.

e.nondisjunction.

7.The term describing the relationship between the number of copies of a gene and how much product is made from the gene is:

a. gene-dosage effect. gene balance.

b. dosage compensation.

c. transcription.

d. aneuploidy.

a. has incomplete penetrance.

b. has complete penetrance.

c. demonstrates variable expressivity.

d. is lethal.

e. is incompletely dominant.

9. A researcher has selfed an autotetraploid plant with the genotype D/D/d/d, and in the resulting progeny she observes a 35:1 phenotypic ratio. What can she conclude from this observation?

a. The progeny from this cross do not demonstrate a standard Mendelian phenotypic ratio.

b. In the 35:1 phenotypic ratio, the 1 represents the phenotype of the d/d/d/d progeny.

c. During meiosis in the D/D/d/d parent plant, it is likely that only bivalents, no quadrivalents or trivalents, formed.

d. It is likely that in this plant species, gametes associate with one another randomly.

e. All of the answers are correct.

a. only variable expressivity.

b. only incomplete penetrance.

c. both variable expressivity and incomplete penetrance.

d. recessive allele lethality.

e. pleiotropy.

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BISC 202 Lecture Notes - Lecture 9: Summer Squash, Mendelian Inheritance, Corn Snake

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