BSC2010 Genetics Concepts

Flashcards covering key genetics concepts from Chapters 12 and 13.

Allele

Alternate versions of a gene.

P Generation

True breeding plants.

F1 Generation

Offspring of the P Generation.

F2 Generation

Offspring of the F1 Generation.

Dominant

Expressed trait.

Recessive

Hidden trait.

Homozygous

Two identical alleles.

Heterozygous

Two different alleles.

Phenotype

Expressed physical traits.

Genotype

Genetic make-up.

Law of Segregation

The two alleles for each character separate during gamete formation.

Testcross

Determine if dominant trait is homozygous or heterozygous by crossing with recessive (pp).

Monohybrid cross

Study of one character.

Dihybrid cross

Study of two characters.

Complete dominance

Heterozygote and homozygote for dominant allele are indistinguishable.

Incomplete dominance

F1 hybrids have appearance that is between that of two parents.

Codominance

Phenotype of both alleles is expressed.

Multiple Alleles

Gene has two or more alleles.

Polygenic Inheritance

The effect of two or more genes acting upon a single phenotypic character.

Pedigree

Diagram that shows the relationship between parents and offspring across two or more generations.

Sex-linked trait

Located on X or Y chromosome.

Locus

Specific location of a gene on a chromosome.

Hemizygous

Condition in males where recessive trait is expressed on the single X chromosome.

Barr body

Inactive X chromosome in a female somatic cell.

SRY gene

Sex-determining region of Y chromosome.

Linked genes

Genes located on the same chromosome and tend to be inherited together.

Linkage map

Genetic map based on percentage of cross-over events.

Amniocentesis

Procedure to remove amniotic fluid around fetus for karyotype.

Nondisjunction

Failure of chromosomes to separate properly in Meiosis I or Meiosis II.

Klinefelter Syndrome

Condition with an extra X chromosome (47XXY or XXY).

Turner Syndrome

Condition with missing X chromosome (45XO or 45X).

Aneuploidy

Abnormal number of chromosomes.

Polyploidy

Condition with two or more complete sets of chromosomes.

Deletion

Removes a segment from a chromosome.

Duplication

Repeats a segment within a chromosome.

Inversion

Reverses a segment within a chromosome.

Translocation

Moves a segment from one chromosome to a nonhomologous chromosome.