Genetics Chapter 3

1. How did Sutton's chromosome theory of inheritance link Mendel's work with a more mechanistic understanding of heredity.

Not listed

2. The occurrence of partial expressivity and incomplete penetrance demonstrates that gene expression can be influenced by biological or environmental context. Explain this statement and give examples to support it.

Not listed

3. The genotype is the physical appearance of a trait.

True

False

4. A testcross can be used to determine whether an individual is homozygous or heterozygous.

True

False

5. The phenotype of a dominant allele is never seen in the F1 progeny of a monohybrid cross.

True

False

6. The probability of a woman giving birth to three girls in a row is 1/8.

True

False

7. The chi-square test is used to determine if observed outcomes are consistent with expected outcomes.

True

False

8. Alleles, genes, and loci are different names for the same thing.

True

False

9. The probability of two or more independent events occurring together is calculated by multiplying their independent probabilities.

True

False

10. Two pea plants with purple flowers are crossed. Among the offspring, 63 have purple flowers, and 17 have white flowers. With a chi-square test, compare the observed numbers with a 3:1 ratio and determine the probability that the difference between observed and expected could be a result of chance.

Not listed

11. The occurrences of partial expressivity and incomplete penetrance demonstrate that gene expression can be influenced by non-genetic factors

True

False

12. A cross produces an F1 ratio of 159:41. What is the probability that this reflects a chance departure from a 13:3 expected ratio?

Not listed

13. A couple has one girl and is expecting a second child. What is the probability that this child will be a boy? After several years and several births, this couple now has six daughters and is expecting a seventh. What is the probability that this child will be a boy?

Like flipping a fair coin, each birth is independent, so in both cases theprobability is ½.

1/2 x 1/2 = 1/4

Not listed

14. Normal recessive genes typically do not produce functional products.

True

False

15. 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 redwinged parents with unknown genotype and observe the following data: Cross Phenotypes 1 72 red-winged, 24 clear-winged 2 4 red-winged 3 96 red-winged a. What is the most likely genotype for each pair of parents?

Neither

All of the above

16. The forked-line method generates genotypes and corresponding probabilities for Mendelian genetic crosses.

True

False

17. Genes come in different versions called:

Alleles

Loci

Genotypes

Chromosomes

Genomes

18. 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 redwinged parents with unknown genotype and observe the following data: Cross Phenotypes 1 72 red-winged, 24 clear-winged 2 4 red-winged 3 96 red-winged Do you think there are a sufficient number of progeny to support each of your answers in the previous question?

Neither

All of the above

19. A man has either an AaBB or AABb genotype with equal probability. a. What is the probability of the man producing an AB gamete?

Neither of them

All of the above

20. The principle of independent assortment can be demonstrated using a monohybrid cross.

True

False

21. A Mendelian dihybrid cross involves one gene and two different alleles.

True

False

22. A man has either an AaBB or AABb genotype with equal probability. a. Assume these genes are unlinked (i.e., assorting independently). What is the overall probability that the man will produce an Ab gamete?

Neither of the above

All of the above

23. A single gene can only have two alleles.

True

False

24. Describe the differences between dominance, co-dominance, and incomplete dominance.

Submit

25. Compare and contrast Mendel's principle of segregation and the principle of independent assortment.

Not listed

Submit

26. Codominant alleles are expressed in individuals that are _____________.

Penetrant

Homozygous

Polymorphic

Heterozygous

Mutually exclusive

27. Honey bees have a haplo-diploid sex determination system where femalesdevelop from a fertilized egg (they are diploid, having one allele from the femalequeen and 1 allele from the male) and males develop from unfertilized eggs (theyare haploid, having only 1 allele from the queen). What is the probability that a daughter will inherit a particular allele from her mother? What is the probability that a son will inherit a particular allele from his mother?

None of the above

28. What is a backcross and a testcross?

Submit

29. Mendel did his genetic work with peas in a Viennese monastery.

True

False

30. Mendel's experiments involved both discrete and continuous genetic traits.

True

False

31. What conclusions did Mendel make from his monohybrid crosses?

Progeny inherit genetic factors from both parents.

Each individual possesses two factors (alleles) that control theappearance of each phenotypic trait.

Individual possesses X from dad and Y from mom.

Submit

32. Two gene loci, A and B, are unlinked (and thus assort independently), and alleles A and B are dominant over alleles a and b. Indicate the probabilities of producing the following.

An AB gamete from an AaBb individual?

An AB gamete from an AABb individual?

An AABB zygote from a cross AaBb × AaBb?

An AaBb zygote from a cross AaBb × AABB?

An Aabb zygote from a cross AaBb × AAbb?

An AB phenotype from a cross AaBb × AaBb?

An AB phenotype from a cross aabb × AABB?

An aB phenotype from a cross AaBb × AaBB?

Submit

33. What is the probability of drawing one card at random from a deck and obtaining the following? (A deck has 52 cards. Each card has a suit—spade, heart, diamond, or club—and a number [1(Ace)–10] or a face—jack, queen, king. Thus, there are 13 cards of each suit and four cards of each number or face.)

The queen of diamonds

Any heart

A 10 (any suit)

Any even-numbered card

An even-numbered spade

Submit

34. In snapdragons, the allele for red flowers is incompletely dominant over the allele for white flowers, and thus heterozygotes have pink flowers. What ratios of snapdragon flower colors would you expect to see among progeny generated from the following crosses?

red × white

red × pink

white × pink

white × white

pink × pink

red × red

Submit

35. In a plant species, you notice that purple and yellow leaf colors, as well as hairy and smooth stems, segregate. You cross a plant with purple leaves and hairy stems to a plant with yellow leaves and hairy stems, and generate the progeny indicated below: Class Phenotypes 1 68 yellow leaves, hairy stems 2 66 purple leaves, hairy stems 3 22 purple leaves, smooth stems 4 25 yellow leaves, smooth stems Total: 181

Indicate the most likely genotypes for each parent.

Propose a hypothesis to explain the progeny results. Based on this hypothesis, what ratios are expected for each of the four classes of progeny?

Using the chi-square method, test your hypothesis and indicate whether you accept or reject it.

Submit

Genetics Chapter 3

1. How did Sutton's chromosome theory of inheritance link Mendel's work with a more mechanistic understanding of heredity.

2.

What first name or nickname would you like us to use?

2. The occurrence of partial expressivity and incomplete penetrance demonstrates that gene expression can be influenced by biological or environmental context. Explain this statement and give examples to support it.

3. The genotype is the physical appearance of a trait.

4. A testcross can be used to determine whether an individual is homozygous or heterozygous.

5. The phenotype of a dominant allele is never seen in the F1 progeny of a monohybrid cross.

6. The probability of a woman giving birth to three girls in a row is 1/8.

7. The chi-square test is used to determine if observed outcomes are consistent with expected outcomes.

8. Alleles, genes, and loci are different names for the same thing.

9. The probability of two or more independent events occurring together is calculated by multiplying their independent probabilities.

11. The occurrences of partial expressivity and incomplete penetrance demonstrate that gene expression can be influenced by non-genetic factors

12. A cross produces an F1 ratio of 159:41. What is the probability that this reflects a chance departure from a 13:3 expected ratio?

13. A couple has one girl and is expecting a second child. What is the probability that this child will be a boy? After several years and several births, this couple now has six daughters and is expecting a seventh. What is the probability that this child will be a boy?

14. Normal recessive genes typically do not produce functional products.

16. The forked-line method generates genotypes and corresponding probabilities for Mendelian genetic crosses.

17. Genes come in different versions called:

19. A man has either an AaBB or AABb genotype with equal probability. a. What is the probability of the man producing an AB gamete?

20. The principle of independent assortment can be demonstrated using a monohybrid cross.

21. A Mendelian dihybrid cross involves one gene and two different alleles.

22. A man has either an AaBB or AABb genotype with equal probability. a. Assume these genes are unlinked (i.e., assorting independently). What is the overall probability that the man will produce an Ab gamete?

23. A single gene can only have two alleles.

24. Describe the differences between dominance, co-dominance, and incomplete dominance.

25. Compare and contrast Mendel's principle of segregation and the principle of independent assortment.

26. Codominant alleles are expressed in individuals that are _____________.

28. What is a backcross and a testcross?

29. Mendel did his genetic work with peas in a Viennese monastery.

30. Mendel's experiments involved both discrete and continuous genetic traits.

31. What conclusions did Mendel make from his monohybrid crosses?

32. Two gene loci, A and B, are unlinked (and thus assort independently), and alleles A and B are dominant over alleles a and b. Indicate the probabilities of producing the following.

34. In snapdragons, the allele for red flowers is incompletely dominant over the allele for white flowers, and thus heterozygotes have pink flowers. What ratios of snapdragon flower colors would you expect to see among progeny generated from the following crosses?