Intro to Heredity
_________ are passed down from generation to generation.
Traits
Genotype with one dominant and one recessive allele.
Ex. Hh
Heterozygous
The allele combination of the gene pair is represented by the letters.
Ex. BB, Bb, bb
Genotype
Where do the parent genotypes go on a Punnett square?
Draw an example of your paper.
Teacher will check it
________ are small segments of DNA that carry instructions for the traits organisms have.
One of two or more alternative forms of a gene.
Allele
The physical appearance of a trait.
Ex. Blonde hair, blue eyes, freckles
Phenotype.
Cross two homozygous curly tailed critters.
Curly: T
Straight: t
What are possible genotypes? Must draw a punnett square to get checked by teacher.
TT
________ is your physical features.
Phenotype
A trait that is represented by a capital letter. Ex. H
Dominant
Genotype with two dominant or two recessive alleles.
Ex. HH or hh
Homozygous
Cross a homozygous curly-tailed critter and a straight-tailed critter.
Curly: T
Straight: t
Create a punnett square and determine possible genotypes
All four offspring (4/4) will be Tt All four offspring (4/4) will have curly tails
Humans have 23 pairs of _____________.
Chromosomes
A trait that is represented by a lower case letter.
Ex. h
Recessive Trait
A tool used to determine the genotypes of the offspring of two parents.
Cross two critters heterozygous for tail style.
Curly (T)
Straight (t)
Create Punnett square. Determine possible genotypes and the probability of each phenotype.
¼ of the offspring will be TT ½ (2/4) will be Tt ¼ will be tt ¾ of the offspring will have curly tails and ¼ will have straight tails
The passing of traits from parent to offspring is called ____________.
Heredity
Traits are either ________ or ___________. ___________ means they are passed down through genes. _________ means they are learned.
Inherited or Acquired.
Inherited means they are passed down through genes. Acquired means they are learned.
The mathematical chance that something will happen. Can be calculated by using a Punnett square.
Probability
Cross a critter heterozygous for tail style and a critter homozygous for a curly tail.
Create a punnett square to determine the possible genotypes and probability of each phenotype.
½ of the offspring will be TT ½ will be Tt All four offspring (4/4) will have curly tails