Unit 8
Gene
A chunk of DNA that codes for a particular trait
Heterozygous
Having two different alleles
Homozygous
Having two of the same alleles
Diabetes
A disease where a person has a problem with the hormone insulin
Pedigree
A family tree of genetic traits
Allele
A letter in the genotype, one of two or more alternative forms of a gene.
Karyotype
A picture of a person's chromosomes that doctors can use to diagnose some genetic disorders and see the gender of the offspring. It shows extra, missing, and damaged chromosomes
Independent Assortment
An event in Metaphase I of Meiosis I in which chromosomes are sorted randomly, thus, adding to the genetic variations created during crossing over
Crossing Over
An event in Prophase I of Meiosis I in which chromosomes hug, break apart, and exchange genetic material. This increases variation in each gamete. All of the gametes in an organism will continue the same DNA, yet in different combinations
Sex-linked inheritance
An inheritance pattern that is on the X chromosome
Co-dominant inheritance
An inheritance pattern where two traits are expressed equally
Incomplete dominance inheritance
An inheritance pattern where two traits blend to form a new phenotype
Meiosis
Cell division that creates 4 haploid gametes (sperm and egg) with 23 chromosomes in humans
Mitosis
Cell division that creates body cells with 46 chromosomes in humans. The process is necessary for growth and repair in organisms
Nondisjunction
Failure of chromosomes to separate properly during meiosis I, resulting in gametes with additional or insufficient numbers or chromosomes
Genetic Variation
Differences that occur between parent and offspring
Phenotype
Observable characteristics/traits
PKU
Phenylketonuria, a recessive genetic disorder where a person can not process the amino acid phenylalanine
Expression
The appearance of a phenotype of a particular gene
Genotype
The genetic makeup of a cell
Genetic Trait
The individual's phenotype or observable traits