Genetics Flashcards
Genetics
The branch of biology dealing with heredity and the laws governing it
Base pairs
Pairs of nucleotides that bond the two strands of the DNA double helix
Sex chromosomes
Chromosomes that determine sex
Autosome
Any of the chromosomes other than the sex determining chromosomes
Karyotype
A picture of chromosomes arranged in numerical order by size
Genes
The basic unit of heredity, made of DNA
Genetic map
The method of indicating the physical location of genes on chromosomes
Alleles
Variations of the same gene
Homozygous
Possessing two identical alleles for a trait
Heterozygous
Possessing two different alleles for a trait
Genotype
The genetic makeup of an individual
Phenotype
The outward appearance of an individual
Dominant
An allele that is completely expressed whenever possible and suppresses the expression of the other alleles
Recessive
An allele that is not expressed unless the individual is homozygous
Punnett Square
A grid used to predict the genotypes and phenotypes of offspring
Genetic Carrier
Heterozygous individual in which a recessive allele is not displayed
Incomplete dominance
Occurs when neither of the alleles of a gene is totally dominant over the other (red+white=PINK)
Co-dominance
When both alleles are fully expressed in the phenotype (black and white together)
Sex-linked inheritance
Alleles that located on the sex chromosomes (X only)
Lethal Gene
Genes that when homozygous, cause the fetus to die prior to birth
Polygenic
Influenced by multiple genes
Amelanistic
Absence of black pigment
Anerythristic
Absence of red pigment
Dihybrid cross
Genetic cross for two different traits
