genetics Flashcards
How are traits determined?
Traits are determined by genes on chromosomes
What causes dominant traits?
Dominant traits mask, hide or over ride recessive traits
What causes recessive traits to be visible? (phenotypically)
recessive traits are only shown if there are 2 recessive traits (homozygous recessive)
Define Homozygous
Homozygous refers to 2 of the same trait (Ex. AA or aa)
Define Heterozygous
Heterozygous means having 1 of each allele. (Ex. Aa)
What is a phenotype?
A phenotype is a physical trait, or physical apperence (Ex. eye colour being brown or blue)
What is a genotype?
A genotype is the genetic code for a Phenotype, its the genetic makeup of an organisam (Ex. B-Brown, b-blue; genotype for Heterozygous Brown= Bb)
What is a Punnett square? What are they used for?
A Punnett square is a visual representation of the maternal and paternal genetics. They are used to display the possible outcomes from the offspring
Who is Gregor Mandel?
Gregor Mandel is the father of genetics
What are Alleles?
Alleles are different forms of a trait (Ex. A a )
Define Segregation
Segregation is the separation of Alleles
How many traits and gametes in a monohybrid cross?
In a monohybrid cross there is 1 trait and 2 gametes
How many traits and gametes in a Dihybrid cross?
In a dihybrid cross there is 2 trait and 4 gametes
How many traits and gametes in a trihybrid cross?
In a trihybrid cross there is 3 trait and 8 gametes
Define gametes
Sex cells hold a trait for the alleles (Ex. A, a)
Define offspring
Offspring is the results of crossing 2 sets of gametes
Where are genes found?
Genes are part of the DNA, which is found on the chromosomes
What is the ratio of a completely heterozygous dihybrid cross?
The ratio is 9-3-3-1
Dominate both- 9
dominant 1st- 3
dominant 2nd- 3
Recessive both- 1
What does completely Heterozygous mean?
Completely heterozygous means both Traits are heterozygous/different (Ex. AaBb)
What does completely dominant mean?
Completely dominant means both traits are Dominant
What does maternal mean?
Maternal refers to the mothers genotype
What does paternal mean?
Paternal refers toe the fathers Genotype
What was Gregor Mandel’s theories?
Gregor Mandel had the theories for physical traits, he thought genes would be found on the same spot of homologous chromosomes
