Genetics Need-to-Know
Biology
Name: ____________________________________________ Period: ____________
Genetics Unit Need-to-Know
Be able to know, use, and explain the following vocabulary: see vocab sheet and Keystone Glossary for
definitions.
allele
gene
mutation
biotechnology
gene splicing
nondisjunction
chromosomal mutation
gene therapy
phenotype
chromosomes
genetic engineering
point mutation
cloning
genetically modified organism
polygenic trait
co-dominance
genetics
recessive inheritance
crossing over
genotype
sex-linked trait
dominant inheritance
incomplete dominance
translocation
frame-shift mutation
inheritance
gamete
multiple alleles
1.
A trait is a physical or behavioral characteristic that is passed from parents to offspring.
2. Genetics is the field of biology that studies how traits are inherited.
3. Traits are determined by genes that are found in the DNA.
4. Alleles are the various forms of a trait that exist.
5. The dominant allele is the allele that shows.
6. The recessive allele is the allele that is hidden.
7. A genotype is the combination of alleles a person inherits for a trait.
8. The phenotype is the trait that a person has based on their genotype.
9. If a person is heterozygous for a trait, then they inherit two different alleles.
10. If a person is homozygous for a trait, then they inherit two of the same alleles.
11. Mitosis is the type of cell division that produces 2 identical daughter cells.
12. Meiosis is the type of cell division that produces 4 reproductive cells.
13. The environment can also have an effect on a person’s traits.
Example – flower color in hydrangeas; skin color in humans
14. Chromosomal mutations are damage to chromosomes due to physical or chemical disturbances or
errors during meiosis.
-Can only be inherited from sex cells
-can be a change to the chromosome structure or the chromosome number
15. A point mutation may or may not cause a change to the amino acids.
16. A nonsense mutation changes an amino acid to a stop codon.
17. Nondisjunction occurs during meiosis and changes the chromosome number of the daughter cells.
18. Cloned DNA will produce DNA with the same exact sequence of bases.
Genetics Need-to-Know
Biology
Types of Inheritance- be able to complete a punnett square for these types of problems. For examples, see the
“Genetic Crosses” packet.
Codominance is a type of inheritance where both alleles show equally and separately.
Example – checkered chickens have black and white feathers.
Incomplete dominance is a type of inheritance where the heterozygote is a blend of the two alleles.
Example – pink carnations (mix of red and white)
Multiple alleles refers to a type of inheritance where more than two alleles exist for a trait.
Example - human blood types have 3 alleles; rabbit fur has 6 alleles
A sex-linked trait is a trait that is determined by genes on the X or Y chromosome.
Example – color-blindness is on the X chromosome
A polygenic trait is a trait that is determined by a combination of genes.
Example- human height; skin color