Genotype & Phenotype

Genotype & Phenotype

Review terms

-Traits: different characteristics

-Heredity: the passing of traits from parents to offspring

-Genetics: the study of how traits are passed from parents to offspring

Multiple Select

Pea plant TRAITS that Mendel observed included (choose all correct answers)

• flower color

• pod shape

• water use

• seed color

• plant stem length

Dominant and Recessive traits

•  A dominant trait is a genetic factor that masks another genetic factor.

• A recessive trait is a genetic factor that is masked or hidden by the presence of a dominant factor.

Multiple Choice

A trait that masks another trait is

• dominant

• recessive

• strange

Chromosomes & Genes

• Chromosome: a collection of genes grouped together in a threadlike strand of DNA

• Gene: the genetic information for one trait, such as flower color or stem length

Allele

• A version of a gene that controls a trait. 

• Example – trait: flower color (purple or white) Each gene has one allele (version of the gene) that controls flower color that may be passed from parent to offspring. 

Using symbols in genetics

• Dominant alleles are represented using CAPITAL letters

• Recessive alleles are represented using lowercase letters

Multiple Choice

Dominant alleles are represented using CAPITAL letters.

• true

• false

genotype = genetic makeup

phenotype = physical appearance or visible traits

Genotype

• The gene combination for a trait, represented by a combination of alleles

• For example Tt, tt, TT

• You CANNOT see and organism's genotype

Multiple Choice

If you look carefully, you can see an organism's genotype

• true

• false

Phenotype

• Organism's physical appearance or its visible traits

• For example the flowers of pea plants can be either purple or white

• You CAN see on organism's phenotype

Multiple Select

Which of the following are examples of phenotypes for pea plants? (choose all correct answers)

• purple flowers

• PP

• green seeds

• tall stems

• tt

Multiple Select

Which of the following are examples of phenotypes for people? (choose all correct answers)

• brown eyes

• freckles

• BB

• Ff

• hitchhicker's thumb

Homozygous

• -When the two alleles of a gene are EXACTLY the same

• -Homozygous dominant has two CAPITAL letters. (TT, FF, RR, PP)

• -Homozygous recessive has two lowercase letters. (tt, ff, rr, pp)

Heterozygous

• -When the two alleles of a gene are different, one dominant and one recessive

• -One capital, one lowercase

• Tt, Ff, Rr, Pp

homozygous vs heterozygous

• 2 dominant alleles = homozygous dominant AA

• 2 recessive alleles = homozygous recessive bb

• 1 dominant & 1 recessive allele = heterozygous Cc

Multiple Select

Choose ALL examples of HETEROZYGOUS genotypes

• Tt

• tt

• RR

• Hh

• Bb

Multiple Select

Choose ALL examples of HOMOZYGOUS genotypes.

• TT

• hh

• Rr

• bb

• Hh