GENES & INHERITANCE Review PPT

Alleles, polygenic, phenotype, genotype, dominant, recessive, Punnett squares, pedigree, incomplete dominance, co-dominance, multiple alleles, (blood types), sex-linked traits

This is the scientific study of heredity. GENETICS

This person is considered the Father of Genetics Gregor Mendel

Mendel’s experiments What did Mendel work with? Pea plants Why are they good to be used in genetics? 1) easy to grow 2) produce lots of offspring 3) have a short life span 4) have many traits in one of two contrasting form, like tall and short plants

What is it called when genes come in different forms? Alleles

These are factors found on chromosomes that determine specific traits. Genes

Single genes determining single traits A gene that masks another gene. Dominant gene [characterized by a capital letter] What is a gene that is masked by a dominant gene? Recessive gene [characterized by a lowercase letter]

Single genes determining single traits This is a way to show possible allele combinations of offspring. Punnett squares G is dominant for green pea pods. g is recessive for yellow pods.

Punnett squares Homozygous dominant Homozygous recessive Heterozygous both genes are dominant AA Homozygous recessive both genes are recessive aa Heterozygous one dominant and one recessive gene Aa

Punnett Squares What is genetic makeup? Genotype What is physical appearance or the traits expressed? Phenotype

Most cases of genetics Traits of different genes on different chromosomes. Polygenic traits [does not follow single gene rules]

This is chart to show traits are passed down through generations This is chart to show traits are passed down through generations. Usually to show the transmission of a genetic problem. Pedigree

This is a case where neither gene is totally dominant over another This is a case where neither gene is totally dominant over another. Or neither allele is dominant. Or both are dominant. Heterozygous creates a blend. Incomplete dominance

This is where both dominant alleles are expressed in some way. Codominance

This is a case where there are many genes for a trait. Multiple alleles A is dominant B is dominant A and B are codominant O is recessive

These are genes carried on the X-chromosomes of the sex chromosomes, but not the Y. Sex-linked inheritance

What is a called when a person contains the gene for a trait, but does not present it? [the person is heterozygous] Carrier