Genetics Flashcards
is the study of heredity. It involves studying how traits are passed from parents to offspring.
Genetics
is the passing of traits from parents to offspring.
Heredity
are the characteristics of an organism. Examples are eye color, freckles, height or dimples.
Traits
thread-like structures in the nucleus of cells that carry genetic information. It consists of a long strand of DNA containing many genes.
Chromosome
Deoxyribonucleic acid is a molecule made up of nucleotides that contains genetic information for cell growth, division and function.
DNA
a segment on a chromosome that determines a specific trait. These are the units of heredity.
Gene
a gene that is masked by a dominant gene, and is only expressed when two copies of the gene are present
Recessive
a gene variant that is expressed more strongly than other versions of the same gene - the dominant allele masks the effect of the recessive allele
Dominant
a different form or version of a gene - they usually occur in pairs
Allele
the observable traits or physical appearance of an organism - Ex: brown eyes or blue eyes
Phenotype
the genetic make up or code of an organism - Ex: BB, Bb, bb
Genotype
An organism with two different alleles for a trait is called heterozygous or hybrid.
Example: A heterozygous tall plant (Tt) expresses the dominant allele (T or tall) and thus, is tall.
heterozygous
If an organism has two of the same kind of gene for a trait, it is called pure or homozygous.
Example: Homozygous brown eyes (BB) ~ Homozygous blue eyes (bb)
homozygous
