Download Unit 2 Review Sheet File

SBI3U – Genetic Processes
Name:
UNIT 2 TEST REVIEW SHEET
Note: If you are absent for the test, a parent/guardian must phone me at 416-850-8889 on the morning of the test
to explain the absence.
TOPICS ON TEST
A good set of notes (with homework completed) and handouts is your best studying tool. The use of the textbook
is also encouraged.
DNA Structure
 Be able to label a diagram of DNA
 Understand complementary base-pairing
Key Terms: nucleotide, deoxyribose sugar, nitrogenous bases (adenine, thymine, cytosine and guanine)
and phosphate
Meiosis
 Describe what goes on during both divisions and their stages
 Understand when and how the daughter cells become genetically unique from each other
 Be able to relate the process of Meiosis with Mitosis (comparison chart)
Key Terms: sister chromatids, crossing-over, tetrad, homologous chromosomes, haploid, diploid,
daughter cells, independent assortment.
 Errors in meiosis: Disjunction and the syndromes associated with it. (e.g. Down Syndrome, Klinefelterès
Syndrome and Turner’s Syndrome)
 Symptoms of the above mentioned syndromes
 Be able to interpret a human karyotype to determine the type of syndrome.
 Gametogenesis: Oogenesis and spermatogenesis
Mendelian Genetics
 Mendel’s experiments and his two laws of genetics; the appropriateness of his choice of the garden pea
for his investigations.
 Monohybrid (single-trait) crosses and the use of Punnett square.
 Testcross – its purpose and results
 Dihybrid crosses – the inheritance of two pairs of traits together.
Key Terms: alleles, dominant and recessive, P generation, F1 generation, F2 generation, phenotype,
genotype, purebred, homozygous, heterozygous
Extensions of Mendelian Genetics
 Genetics After Mendel: Co-dominance, incomplete dominance and multiple alleles
 ABO Blood System and be able to describe the effects of receiving the incorrect blood type; be familiar
with the symbols used for the alleles (IA, IB and i)
 Sex determination
 Sex-lined inheritance
Pedigrees
 Know how to read them and create them
 Pedigree Analysis: Determine the type of inheritance displayed using a pedigree (autosomal recessive,
autosomal dominant and X-linked recessive inheritance)
Suggested Review Questions
Chapter 4 Review: #3, 6-8, 19, 20, 22, 25, 29, 33, 46,
Chapter 6 Review: #1, 18 and 44
49, 50 and 64
Unit 2 Review: #1, 3-14, 16-18, 21, 32, 34, 37, 39, 51,
Chapter 5 Review: #1-6, 8, 21-23, 25, 26, 28, 31 and 33 60, 69
Answers to be posted on the class Moodle site
Additional Review Questions
1. In pea plants, tall is dominant and short is recessive. Using a Punnett square, work out the genotypes and
phenotypes of the cross between
a. two heterozygous tall plants, and
b. a short plant and a homozygous tall plant.
2. (a) List two events that take place only during prophase I of meiosis, and not during either prophase II of
meiosis or the prophase of mitosis.
(b) How does synapsis (crossing-over) increase the genetic variability in gametes.
(c) List three differences between meiosis and mitosis.
(d) Explain how the process of meiosis accounts for Mendel’s observations and conclusions concerning
factor (gene) segregation and independent assortment.
3. How many different types of gametes would each of the following parent plants be capable of producing?
List the possible combinations.
a. Tt
b. AaBb
c. Rrtt
d. RrSsTt
4. Two parents, both with blood type B, have a child who has blood type O. Explain, by using a Punnett
square, how this is possible.
5. Explain why having blood type AB is a case of co-dominance rather than incomplete dominance.
6. The cross between pure red four o’clock flowers and pure white ones results in all pink offspring. Explain
what has happened.
7. Describe sex determination in humans. Explain why in humans the father’s gametes determine the sex of
a child.
8. Explain why some human traits are sex-linked and describe the phenotype of one or more of these traits,
e.g. hemophilia, colour-blindness. Use a Punnett square.
9. Why do woman carry sex-linked conditions and men get them? Explain.
10. Colour blindness is sex-linked recessive trait. A heterozygous (for eye colour) brown-eyed normal male is
married to a heterozygous brown-eyed, colour-blind female. Use a Punnett square to determine the
answer to the following questions:
a. What is the probability that they will have a daughter who is a carrier for colour blindness with
brown eyes?
b. What is the probability that they will have a son who is colour-blind with blue eyes?
c. What is the probability that they will have a colour-blind child?