Level 1 Genetics Review Sheet
Organize your materials in the following order:
1. Notes packet containing the following (divided by when each was done):
 Gregor Mendel (p. 1)
 Alleles/genotype/phenotypes (p. 2)
 Gamete formation/monohybrid cross/probability/testcross (p. 2)
 Dihybrid cross/testcross (p. 3)
 Polygenic inheritance (back p. 3)
 Multiple alleles/codominance (blood)/incomplete dominance (hair, sickle cell,
four o’clock plants) (p.4)
 Viewing the chromosomes/amniocentesis/CVS (p. 5)
 Changes in chromosome number/nondisjunction/changes in chromosome
structure/chromosome mutations (p. 6-7)
 Sex-linked traits (back p. 7)
 Linked genes (back p. 7)
2. Study guide packet (homeworks)
3. Packet of problems:
 Monohybrid crosses
 Probability practice problems
 Dihybrid crosses
 Codominance/Incomplete dominance practice problems
 Sex-linked trait problems
4. Laboratory: Exploring hereditary traits
5. Chapters 23 & 24 practice problems and answer key
Test questions will be based on the following main ideas:
 Be able to explain how Mendel performed his crosses with pea plants – using an
example of a trait he worked with, explain what the parents would look like, the
F1 generation, and F2 generation in terms of appearance and percents for each type
of appearance. Be able to explain why he got the results he got.
 Be able to explain each of Mendel’s laws – dominance, segregation, and
independent assortment using examples of genotypes and phenotypes.
 Vocab: allele, phenotype, genotype, codominance, incomplete dominance, sexlinkage
 Be able to demonstrate (using punnett) squares the following types of problems:
i. Dominance/recessiveness – monohybrid crosses, both forwards and
backwards
ii. Dihybrid crosses – forwards only on test
iii. Codominance – blood type – forwards and backwards
iv. Incomplete dominance – hair, sickle cell, four-o’clock plants – forwards
and backwards
v. Sex-linked traits – hemophilia, color blindness – forwards and backwards
vi. Multiple probability – event happening several times in a row
 For each of the problems listed on the previous side of this sheet, be sure to know
the genotypes to use for each type of problem, and what phenotypes each
represent.
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Be able to explain what a testcross is, and why it would be done.
Be able to explain what a polygenic trait is, and how the interaction of multiple
genes affects the possible phenotypes.
Be able to explain what a karyotype is and why it would be used – what can it
show about the developing baby.
Be able to explain the difference between amniocentesis and chorionic villus
sampling (CVS) in terms of when they are done and how the cells from the fetus
are acquired.
Be able explain what happens to the genes on the chromosomes on each type of
chromosomal mutation, and how these mutations (in general) can affect the
developing baby or the genes on those affected chromosomes.
Be able to explain what a linkage group is, and how Mendel’s law of independent
assortment is affected by it.
Be able to explain what nondisjunction is, how it can occur during meiosis I and
II, and how it affects the number of chromosomes in a person.
Be able to explain how sex-influenced traits occur.