Unit 5 : Heredity Flashcards
what is a trait
a specific characteristic of an organism.
- they can be determined by genes or environment
- they are passed down from parent to off spring
what is heredity
passing of traits from parents to off spring
what is genetics
study of heredity
genetic inheritance occurs both in ____ and ____ reproduction
sexual + asexual
who is gregor mendel
¨Father of genetics¨
- worked in the gardens and his experiments with peas showed that genes are discrete units that keep their separate identities when passed from generation to generation
what are some characteristics of traits
- eye color
- leaf shape
- tail length
- widows peak
what is a ¨ cross ¨
the mating of 2 organisms
what are the 3 medels laws
- Law of segregation
- law of independent assortment
- law of dominance
what is the law of segregation
organisms inherit 2 copies of each gene, one from each parent/ when chromosomes separate in meiosis , each gamate will receive only one chromones from each pair
what is a gene
peices of dna that provide instructions to make a certain protein
- genes determine traits
what is an allele
diffrent versions of genes
- they can be homozygous or heterozygous
what is a geneotype
refers to an organisms combination of alleles
ex BB, Bb, bb
what is a phenotype
PHYSICAL characteristics
ex. blue eyes, brown fur, tall plant, smooth peas
what is a dominant allele
the allele that is showed when 2 different allels are present
ex. AA or Aa
what is the law of dominance
a dominant allele will express itself over a recessive allele
ex. Freckles (F) are dominant over non- freckles (f), if you get the big F then you’ll have freckles
law of independent assortment
inheritance of one trait does not affect the inheritance of another
what is a complex inheritance
not all traits that scientists predicted in test crosses Mendel’s law of inheritance
what is incomplete dominance
dominant allele is not completly expressed when the recessive allele is around
- phenotype will be mixed
ex. Red flower + White flower = Pink flower
what is codominance
alleles work toghther
both traits are fully expressed + separately
when organism has 2 different alleles it’ll express both at the same time
what is polygenic traits
trait produced by 2 or more genes
shows a range in phenotype
ex. skin color, height , eye color
what is multiple alleles
having more than 2 alleles for one gene
ex. blood type or bunny fur
what are sex- linked taits
traits that are specifically on the sex chromosome
ex. color blindness or hemophilia
what is one thing pedigrees can help with
can help determine probibility if offspring will inherit a genetic disorder
affected ____ cannot pass it to their suns but can pass it to their daughters
males
