GENETICS Flashcards
GENETICS
the study of heredity and variation in living organisms
HOW HEREDITARY CHARACTERISTICS ARE TRANSFERRED
by gametes through the fusion of the male and female gametes
GENOME
the complete set of genes of a particular organism / it is a copy of all the essential DNA coding required to synthesize all the proteins the organism needs
MENDEL’S LAW OF DOMINANCE
if two alleles are different, only the dominant one will be expressed
GENOTYPE
the composition of the gene pair for a specific trait
PHENOTYPE
the observable physical characteristic
HOMOZYGOUS
when the two alleles are the same (TT, tt)
HETEROZYGOUS
when the two alleles are diff (Tt)
MENDEL’S LAW OF SEGREGATION
during meiosis, homologous chromsomes pairs seperate. thus each gamete that is produced receives only one allele of a gene pair.
MONOHYBRID CROSSES
a cross where only one hereditary characteristic is investigated at a time
P1 GENERATION
the two parents that are originally crossed
WHEN DO THE TWO CHROMOSOMES OF THE HOM PAIR SEPERATE
during Anaphse I
F1 GENERATION
the first gen offspring
COMPLETE DOMINANCE
when only the dominant allele is observed
INCOMPLETE DOMINANCE
when two homo individuals are crossed and the offspring’s phenotype expresses an intermediate form of the two rents’ characteristics (neither allele is dominant)
(diff letters are used for each charact)
CO-DOMINANCE
when both characteristics are visible when both alleles of the gene pair are equally dominant
BLOOD GROUPS
A - IᴬIᴬ or Iᴬi
B - IᴮIᴮ or Iᴮi
AB - IᴬIᴮ
O - ii
DIHYBRID CROSSES
where two pairs of contrasting characteristics, carried on diff homologous pairs, are crossed
MENDEL’S LAW OF INDEPENDENT ASSORTMENT
The alleles of different genes get sorted into gametes independently of one another.
AUTOSOMES
the 22 chromosome pairs with similar shape of the 23 that humans have
GONOSOMES
aka sex chromosomes
are the 23rd pair which is responsible for sex determination
SEX CHROMOSOMES
XX - female
XY - male
SEX-LINKED GENES
X chromosome, which is larger and can carry many other genes
MUTATIONS
a change in the genetic composition of an organism
GENE MUTATIONS
this occurs as a result in a change in the nucleotide sequence in the DNA molecule