Unit 9 Vocabulary Flashcards
a segment of DNA that codes for a particular trait
Gene
an inherited characterisitic (ex. eye color)
Trait
one set of chromosomes from mom and one set from dad that form a pair
Homologous chromosomes
different versions (alternate forms) for a gene at a single location in the DNA
Allele
observed trait of a organism that masks any other allele
Dominant
masked by a dominant allele
recessive
two copies of the dominant allele
Homozygous dominant
one dominant and one recessive allele
heterozygous
two copies of the recessive alleles
homozygous recessive
the appearance of an organism for a gene
phenotype
the inherited allele combination of an organism for a gene
genotype
the passing of characteristics from generation to generation
heredity
the passing on of traits from parent to offspring
inheritance
the father of genetics; worked with pea plants
gregor mendel
a genetic mating of individuals that are different for only 1 trait (tall vs. dwarf)
monohybrid cross
the parental generation
p generation
the first generation of offspring
F1 generation
the second generation of offspring
F2 generation
eggs or sperm
gametes
alleles are randomly placed into gametes during meiosis
mendel’s law of segregation
alleles are inherited independent from other alleles
mendel’s law of independent assortment
an easy short hand way to predict the outcome of crosses
punnet square
homozygous individual that can only make one type of allele
pure breeding
the offspring from two different pure breeding parents
hybrid
the predicted frequency of offspring genotype from a monohyrbid cross
genotype ratio
the predicted frequency of offspring phenotype from a monohyrbid cross
phenotype ratio
traits that require one dominant allele to be expressed; recessive phenotype requires two recessive alleles to be expressed
simple dominant/ recessive heredity
genetic disorder caused by a dominant allele; individuals have shortened arms and legs
dwarfism
genetic disorder caused by a dominant allele; degenerative neurological disorder
huntington disease
genetic disorder caused by a recessive allele; fat builds up in baby’s brain, killing the baby by age 5
Tay-sach’s
genetic disorder caused by a recessive allele; individuals cannot digest the amino acid phynlalanine
PKU
disorder caused by a recessive allele; individuals accumlate thick mucus in the lungs
cystic fibrosis
disorder caused by a recessive allele; individuals do not contain pigment in their cells
Albinism
heterozygous displays a phenotype that is intermediate between dominant and recessive
incomplete dominance
more than 2 alleles within the population for a particular gene
multiple alleles
when 2 alleles are equally dominant, making an individual that expresses BOTH phenotypes
codominance
genes that are on the X or Y chromosome, like colorblindness
sex linked
sex linked disorder; individuals see colors differently
colorblindness
sex linked disorder; individuals cannot clot blood properly
hemophilia
sex linked disorder; individuals have mental and physical deformities (like an elongated head)
fragile x syndrome
traits that are controlled by more than one gene
polygenic
change in chromosome number
anueploidy
failure of chromosomes to separate accurately during meiosis
nondisjunction
disorder caused by aneuploidy with an extra chromosome #21
down syndrome
disorder caused by aneuploidy with a missing x chromosome
turner syndrome
discrete package of DNA that codes for genes
chromosome
