Download Notes and Study Guide for weeks 8

Notes and Study Guide for weeks 8-10
Read Textbook Chapters 7 and 8
1. Genes and Inheritance (Mendelian Genetics)
A. Understand how inheritance works and why you aren’t a carbon copy of one of your
parents. (Fig. 7.2)
B. Know who Gregor Mendel was and the significance of his work with pea plants.
C. Be able to solve problems that involve dominant and recessive traits, homozygous and
heterozygous traits, and allele frequencies. (Know what these terms mean.)
D. Be able to solve simple problems involving one trait with two alleles or two traits, each
with two alleles (dihybrid cross). You’ll have problems to solve in lab as well.
E. Be able to explain that a genotype is the alleles an individual inherits and that a phenotype
is the actual character trait that someone has as a result of those alleles. Sometimes a
particular phenotype can result from more than one genotype. How can this be? Give an
example:
F. Know what a test cross is and how it is useful in determining an unknown genotype. Fig
7.14.
G. Know what incomplete dominance and co-dominance are and how these influence
phenotype. Fig. 7.18 and 19.
H. What is a polygenic trait and why can this lead to continuous variation?
I. What is pleiotrophy?
J. What happens when the trait you need to know about is regulated by a gene on an X
chromosome? This situation and when the trait is controlled by a gene on the Y
chromosome are both considered sex-linked traits. Why is that? Fig. 7.24. If a man has a
particular allele for a gene on his Y chromosome, will all of his sons inherit this allele?
Will any of his daughters inherit this allele?
K. Genes that are located close together on a chromosome are less likely to be mixed through
crossing over during meiosis. This means that the alleles for these two genes will tend to
be inherited as a group. This situation is referred to as linked genes and the inheritance
pattern will be unusual.
2. Biotechnology (will not be covered on the final exam)
A. What is meant by this term? Why should you care?
B. What are 4 steps used to identify and isolate a portion of DNA that is thought to be an
important gene?
C. What is meant by using a DNA probe?
D. Have you ever eaten bioengineered corn, beans or fish?
E. How does cloning work and what does it mean? Should we try cloning human beings?
F. What is DNA fingerprinting?
3. Evolution and Natural Selection
A. What does evolution mean in general term? When someone says that hairstyles have
evolved, what does that person mean?
> What is meant by biological evolution? In what way is it more specific?
B. Who is Charles Darwin and what did he do? What major events in his life shaped his
scientific work?
C. What 3 observations or conditions support natural selection?
D. What is meant by an organism’s fitness? What is meant by relative fitness? Why is this
really the most important aspect of one’s reproductive success in terms of natural selection?
E. What are 3 things that influence variation in a trait (the mix of alleles in a population for
that trait)? How does this impact natural selection? Fig. 8.10.
F. What is artificial selection? What aspects of your life have been impacted by artificial
selection? What breed is your pet cat or dog? Do you drink milk? Have you worked on a
ranch or farm – what breeds of chicken or livestock did you work with? Etc.
G. What is sexual selection?
> Be able to differentiate between intrasexual selection and intersexual selection.
Remember intra is within and inter means between.
> Be able to give examples of each. If you observe a species and the males are much
larger than the females and they have fighting structures that females lack, which form of
sexual selection is likely to be at work here?
H. Know the difference among directional, stabilizing and disruptive selection.
I. Be able to identify 5 lines of evidence for biological evolution. Be able to explain at least
one example of each.