by Amber and Mariela

what is the study of genetics?

Is the study of a branch in biology that studies heredity.

Who discovered Genetics and how did he do this?

Gregor Mendel, he studied pea plants for his genetic trait discoveries. He grew the pea plants through the selctive cross breeding, by doing this he could tell that over many generations traits from the parents show up in the offspring.

Dominant/Recessive Alleles

Dominant alleles overpower or mask the recessive alleles. Recessive alleles get overpowered or masked and dissapear.


Heterozygous is when the two allelesare different from each other and look like this Gg or Pp. Homozygous is with the two alleles are the same and look like this GG or pp.


Genotype is the combination of the alleles of the organism. Phenotype is the physical apperance or behavior of the organism.

Example of a simple cross in a punnett square

cross Gg and Gg   75% Green     25% GG  50% Gg                                        25% Blue       25% gg

Incomplete Dominance

Phenotype of heterozygous individuals is intermediate between those of the two homozygous.


Phenotypes of both homozygotes produced in heterozygous individuals, both alleles are expressed equally.

What are multiple alleles and what are they used to determine?

The presence of more than two alleles for a genetic trait. The traits the offspring could recieve from the parents.

Sex- linked traits

They are characteristics determined by genes on sex chromosomes. Sex linked traits can be on the X and Y chromosomes. The X chromosome is more common.