Genetics Flashcards
(13 cards)
is the study of heredity. Genetics 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. A chromosome consists of a long strand of DNA containing many genes.
chromosomes
is a molecule made up of nucleotides that contains genetic information for cell growth, division and function.
DNA
segment on a chromosome that determines a specific trait
Genes
a different form or version of a gene
Allele
a gene variant that is expressed more strongly than other versions of the same gene -
Dominant
a gene that is masked by a dominant gene, and is only expressed when two copies of the gene are present
Recessive
the genetic make up or code of an organism - Ex: BB, Bb, bb
genotype
the observable traits or physical appearance of an organism - Ex: brown eyes or blue eyes
phenotype
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)
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.