Punnet Squares, Pedigrees & Blood Typing

Punnet Squares, Pedigrees & Blood Typing

Homozygous

The genotype for each characteristic has the same alleles eg. AA, BB, bb, hh

Heterozygous

The genotype for the characteristic has different alleles eg. Aa, Tt, Dd, Bb

F1

used to represent the first generation of offspring

F2

used to represent the second generation and obtained by crossing two F1 individuals

Carrier

A person who has one recessive allele for a trait, but does not have the trait.

Complete Dominance

one allele is dominant and masks the presence of the other allele

Co-dominance

both alleles are dominant, traits from both alleles show in the phenotype

Autosomal Recessive Pedigrees

* The trait can 'skip' generations
* Two affected parents must produce all offspring affected
* Equal numbers of males and females are affected
* An affected child may have unaffected parents

Autosomal Dominant Pedigrees

* An affected child must have at least one affected parent
* The trait cannot 'skip' a generation
* Two affected parents can have an unaffected child
* Equal numbers of males and females are affected

what does a shaded square in the pedigree represents?

an affected male pedigree symbol

what does a shaded circle in the pedigree represents?

an affected female pedigree symbol

Dominant Trait/Allele

an allele that is fully expressed in the phenotype

Recessive Trait/Allele

An allele that is hidden whenever the dominant allele is present

Trait

A characteristic that an organism can pass on to its offspring through its genes.

Heredity

the passing of traits from parents to offspring

Genes

sections of DNA that determine traits

Alleles

a form of a gene that determines the characteristics

Phenotype

the physical appearance of an organism

Genotype

the combination of genes that code for a trait

incomplete dominance

neither allele is dominant. A blend of two alleles are expressed in the phenotype

Pedrigree

family tree that records and traces the occurrence of a trait in a family

Sexual Reproduction

A reproductive process that involves two parents that combine their genetic material to produce a new organism, which differs from both parents

Chromosomes

threadlike structures made of DNA molecules that contain the genes

Asexual Reproduction

A reproductive process that involves only one parent and produces offspring that are identical to the parent.

A+

antigen: A

antibody: B

donor preferred: A

donors allowed: A & O

RH factor: +

A-

antigen: A \n antibody: B \n donor preferred: A \n donors allowed: A, O \n RH factor: -

B+

antigen: B \n antibody: A \n donor preferred: B \n donors allowed: B, O \n RH factor: +

B-

antigen: B \n antibody: A \n donor preferred: B \n donors allowed: B, O \n RH factor: -

AB+

antigen: A & B \n antibody: neither A or B \n donor preferred: AB \n donors allowed: AB, A, B, O \n RH factor: +

AB-

antigen: A & B \n antibody: neither A or B \n donor preferred: AB \n donors allowed: AB, A, B, O \n RH factor: -

O+

antigen: neither A or B \n antibody: both A & B \n donor preferred: O \n donors allowed: O \n RH factor: +

O-

antigen: neither A or B \n antibody: both A & B \n donor preferred: O \n donors allowed: O \n RH factor: -

What blood type is the Universal Donor & why

O-, because there is no antigens and no RH factor to affect the other blood types

What blood type is the Universal Recipient & why

AB+, because it has both antigens and a positive RH factor

RH factor

an inherited protein that can be found on the surface of the red blood cell.

If your blood type is positive, then your blood cells have the Rh protein.

If your blood type is negative, then your blood cells lack the Rh protein.