Ch 12 Study Guide
Part I – Multiple Choice - The following words, phrases, definitions, etc. will be used on the
multiple choice portion of the test.
Gregor Mendel – Father of modern genetics. Did experiments with pea plants. Mendelian
genetics use dominant and recessive genes.
P generation – Parent generation in genetics.
F1 generation – First generation of offspring.
F2 generation – 2nd generation of offspring
Mendel’s experiments – Did experiments with pea plants. Found that when two
purebred(homozygous) parents are mated that the F1 generation shows none of the recessive
traits. In the F2 generation, the recessive gene reappears.
Polygenic inheritance – When more than one gene plays a role in determining a trait
meiosis and stages – PMAT! – Meiosis has cell divisions and two of each of the following stages.
Prophase, Metaphase, Anaphase, and Telophase. Results in four sex cells with half of the
genetic material in each cell.
Punnett square
*Be able to read/understand the following:
1. Basic\Mendelian genetics – Dominant and Recessive traits.
2. Codominance – Dominant and recessive traits are both visible in heterozygous
individuals. Example – Black and white feathers in chickens.
3. Incomplete Dominance – Dominant and recessive traits are mixed in heterozygous
Individuals. Example – Red and White genes mix to form pink flowers.
4. Polygenic inheritance (double squares) – Several genes determine a trait. Example –
height. AaBb X aaBb
5. Sex-linked traits – traits that are linked to the X chromosome. Example – male
pattern baldness, color blindness, hemophilia. XBXb x XbY. Females can be carriers.
6. Blood types – AB, A, B, O are blood types (phenotypes) – AB, AA, AO, BO, BB, and OO
are the genotypes for these blood types. O is a recessive blood type.
Hybridization – Crossing (mating) individuals with different desired traits.
Alleles – different forms of the gene.
Genes – the factors that control a trait
Inbreeding – breeding individuals that have similar desirable characteristics. Can result in birth
defects and an increased likelihood of having unwanted recessive alleles.
Chromosome theory of inheritance – That genes pass from parents to offspring on
chromosomes.
Heterozygous – Individuals with two different alleles of a gene. Ex. – Hh Bb Tt
Homozygous – Individuals with two of the same alleles for a gene. Ex – hh HH BB TT tt bb
Hybrid – an individual with two different forms (alleles) for a gene. Or a cross between two
genetically different individuals. Example – Zonkey or Hh
Purebred – an individual with the same forms of a gene. HH BB tt rr
Phenotype – an individual’s physical appearance or visible traits
Genotype - an individual’s genetic makeup
genetic engineering – genes from one organism are transferred into the DNA of another.
Mitosis – used in regular cell replication (multiplying). PMAT! Only one division!
Ch 12 Vocabulary
Part II – Short Answer
1. Will a person with a tattoo on his or her arm pass this characteristic on to offspring?
Explain.
2. In pea plants, green pod color is controlled by a dominant allele. Yellow is controlled by
a recessive allele. Explain why a plant with yellow pods can never be a hybrid.