1. Copyright © 2009 Pearson Education, Inc. Active Lecture Questions for Biology: Concepts & Connections, Sixth Edition Campbell, Reece, Taylor, Simon, and Dickey Chapter 9 Patterns of Inheritance

2. Copyright © 2009 Pearson Education, Inc. Concept Check The figure diagrams one of the genetic crosses that helped Mendel form his theories of inheritance. Which process distributes “P” alleles to approximately one half of the F 1 gametes and the “p” allele to the other half? 1)Independent assortment. 2)Mitosis. 3)Meiosis. 4)Chromosome crossover.

3. Copyright © 2009 Pearson Education, Inc. Answer The figure diagrams one of the genetic crosses that helped Mendel form his theories of inheritance. Which process distributes “P” alleles to approximately one half of the F 1 gametes and the “p” allele to the other half? 3)Meiosis.

4. Copyright © 2009 Pearson Education, Inc. Concept Check Mendel’s principle of independent assortment holds true only for traits with genes that 1)are on homologous chromosome (linked). 2)are on separate chromosomes (unlinked). 3)have loci far apart on homologous chromosomes. 4)are both “1” and “2”.

5. Copyright © 2009 Pearson Education, Inc. Answer Mendel’s principle of independent assortment holds true only for traits with genes that 4)are both “1” and “2”.

6. Copyright © 2009 Pearson Education, Inc. Concept Check The traits studied by Mendel were mostly discrete traits with two phenotypes. Many traits such as human height vary continuously. Which of the following describe the inheritance of continuously varying traits using Mendel’s rules of inheritance? 1)Two or more genes interact to produce the variation in the trait apparent in the population of the organism. 2)Two or more alleles interact to produce the variation in the trait apparent in the population of the organism. 3)Mendel’s principles do not apply to continuously varying traits. 4)Traits with continuous variability are not influenced by heredity.

7. Copyright © 2009 Pearson Education, Inc. Answer The traits studied by Mendel were mostly discrete traits with two phenotypes. Many traits such as human height vary continuously. Which of the following describe the inheritance of continuously varying traits using Mendel’s rules of inheritance? 1)Two or more genes interact to produce the variation in the trait apparent in the population of the organism.

8. Copyright © 2009 Pearson Education, Inc. Interpreting Data Trichomes are small plant hairs. The first graph represents the distribution of trichomes along the petiole (stem) of the first true leaf in a population of Wisconsin Fastplants (Brassica rapa). Which of the following inheritance patterns would most likely lead to results such as these? 1)Pleiotropy 2)Multiple alleles 3)Incomplete dominance 4)Polygenic inheritance

9. Copyright © 2009 Pearson Education, Inc. Answer Trichomes are small plant hairs. The first graph represents the distribution of trichomes along the petiole (stem) of the first true leaf in a population of Wisconsin Fastplants (Brassica rapa). Which of the following inheritance patterns would most likely lead to results such as these? 4)Polygenic inheritance

10. Copyright © 2009 Pearson Education, Inc. Interpreting Data Students selected the top 15% hairy plants as parents for the second generation of plants. The results of these crosses are graphed below. Which of the following is a conclusion consistent with the data? 1)The results of the selection experiment support the hypothesis that inheritance of trichomes in fastplants is polygenic. 2)The results of the selection experiment do not support the hypothesis that inheritance of trichomes in fastplants is polygenic.

11. Copyright © 2009 Pearson Education, Inc. Answer Students selected the top 15% hairy plants as parents for the second generation of plants. The results of these crosses are graphed below. Which of the following is a conclusion consistent with the data? 1)The results of the selection experiment support the hypothesis that inheritance of trichomes in fastplants is polygenic.

12. Copyright © 2009 Pearson Education, Inc. Interpreting Data The students decided to carry out the investigation for one more generation. Again, they selected the top 15% of the hairy plants as parents Which of the following results would be consistent with the hypothesis that the inheritance of trichomes is polygenic? 1)The distribution and mean number of hairs continues to shift to the right. 2)The distribution narrows but the mean does not shift. 3)The distribution curve spreads out but mean does not shift.

13. Copyright © 2009 Pearson Education, Inc. Answer The students decided to carry out the investigation for one more generation. Again, they selected the top 15% of the hairy plants as parents Which of the following results would be consistent with the hypothesis that the inheritance of trichomes is polygenic? 1)The distribution and mean number of hairs continues to shift to the right.

14. Copyright © 2009 Pearson Education, Inc. Biology and Society Every state screens newborn infants for certain metabolic disorders such as phenylketonuria (PKU). The March of Dimes recommends that every newborn be tested for 9 different metabolic disorders as well as hearing. DNA technology has opened up a number of additional tests that could be run for other genetic disorders. Do you think that states should shoulder the responsibility to expand the number of screening tests on newborns to include all of the relatively common disorders?

15. Copyright © 2009 Pearson Education, Inc. Biology and Society Assume that you have a history of Huntington’s chorea in your family. (While the disease is not common,obviously there’s a chance that for few of you this is a very real dilemma.) Huntington’s is a fatal condition that strikes during middle age and is inherited as a dominant trait—you only need one copy of the HD allele. Today, DNA screening tests are available but currently there is no way to stop the course of the disease. Some people at risk take the test—others do not. Would you take the screening test for Huntington’s if you were at risk?

16. Copyright © 2009 Pearson Education, Inc. Biology and Society Early in the history of genetics a movement developed known as eugenics. The goal of eugenics was to “breed” a better human race by using social pressures to encourage reproduction for those with “good” genes and discouraging those with “bad” genes. Eugenics led to bad legislation in the U.S. and eventually was used by the Nazis in Europe to justify much of their atrocities. Today, genetic research is providing ever greater detail into the workings of each and everyone of us—including genetic influences on behavior and personality. For some this is an opportunity to fully realize our individual potentials—for others this research dredges up memories of eugenics. As a member of society do you think it is important to heed the lessons to be learned from eugenics as we explore more deeply into the genetics of human beings?