Genetics

Question 1

What are Mendel’s 2 Laws?

Answer 1

1. Law of Segregation: alternative versions of genes cause variation in the inherited traits – organisms inherit 2 alleles (mom & dad)
2. Law of independent assortment: Genes are packaged into gametes with all possible combination of alleles

Question 2

What is the Monohybrid compare ratio for heterozygous crosses?

Answer 2

Aa x Aa
Ratio: 3 : 1

Question 3

What is the Dihybrid compare ratio for heterozygous crosses?

Answer 3

BbSs x BbSs
Ratio: 9 : 3 : 3 : 1

Question 4

What is the compare ratio for heterozygous crosses for Incomplete?

Answer 4

CwCw x CrCr
Cp (Cw Cr)
Ratio 1: 2 : 1

Question 5

Genetic Patterns: Simple Autosomal Recessive

Answer 5

• Only expressed by homozygous recessive individuals (aa)
• Carrier: keeps allele but doesn’t exhibit disease therefore can skip generations
  ie: sickle cell, albinism, CF, Tay Sach’s

Question 6

Genetic Patterns: Autosomal Dominant Inheritance

Answer 6

• Traits produces with at least 1 dominant allele (AA, Aa, Aa)
• Usually not fatal
• Disease: Dwarfism, Huntington’s
• Sometimes double dominance: deadly / miscarriage

Question 7

Genetic Patterns: Sex-linked Recessive Inheritance

Answer 7

• Only on the X or Y
  ie: Colour blindness, hemophilia

Question 8

What is CoDominance

Answer 8

Genes is a population that can exist in more than one form (more than 2 alleles)
ie: Blood Type