Introduction to Gentetics

Genotype

Genotypes are allele set that determines the expression of a trait or characteristics and is a gene combination of at least two letters.


Examples

  • TT, Tt, tt
  • DD, Dd, dd
  • RR, Rr, rr

Phenotype

Phenotype is the physical appearance of an organism through the expression of its genes.


Examples

  • genotype- Ee / phenotype- green eyes
  • genotype- ff / phenotype- blonde hair
  • genotype- YY / phenotype- widows peak

Homozygous

Homozygous means to code for two identical alleles with the same trait.


Examples

  • HH
  • DD
  • rr

Heterozygous

Heterozygous is a pair of genes where one allele is dominant and one is recessive.


Examples

  • Hh
  • Ll
  • Tt

Dominant

Dominant allele is the trait that hides or masks the recessive gene and is represented through a capital letter.


Examples


  • TT
  • ZZ
  • LL

Recessive

Recessive allele is the trait that is taken over by a dominant gene. The trait can still show if paired with another recessive allele.


Examples

  • kk
  • rr
  • ee

Questions

“How can someone predict the traits of offspring?”

  • You can predict the traits of an offspring by using a punnet square and inputting what the parent traits are.
“Why is it important to study the principles of inheritance (how traits are passed on to offspring)?”

  • It is important to study this to understand how traits are given to offspring and what determines how they get those traits.