Multi-Trait Inheritance (lesson six)

Question 1

true or false: many traits are inherited through only one gene!

Answer 1

False

Question 2

discontinuous variation

Answer 2

• the traits Mendel looked at in pea plants, one characteristic didn’t interact with any others
• I.e. pea colour did not interact or effect if it was wrinkled

Question 3

Inheritance of Traits

Answer 3

• Most traits that are inherited are actually controlled by groups of genes, not one single gene

Question 4

continuous variation

Answer 4

• Because in nature most traits are controlled by multiple genes, many times the phenotype is a result of a group of genes
• This means the trait may be affected by genes around it that may have an additive or a negating effect on the gene
• Examples would include skin colour, hair colour, eye colour and height
  This is called continuous variation

Question 5

Mendel’s Experiments Expanded

Answer 5

• Mendel looked at the inheritance of multiple traits with discontinuous variation
• When you look at how individuals inherited two pair of alleles you are performing a dihybrid cross
• You can still look at inheritance patterns of the P, F1 and F2 generations in the same way we did for monohybrid crosses

Question 6

Multi-Trait Inheritance

Answer 6

• An individual who is heterozygous for two characteristics can produce 4 possible types of gametes
• For example a RrYy individual can generate gametes of RY, Ry, rY or ry

Question 7

why is the FOIL method used?

Answer 7

the FOIL method on the parent genotype to see the potential gametes:

Question 8

FOIL

Answer 8

-F = first
-O = outside
-I = inside
-L = last

Question 9

Mendel’s Law of Independent Assortment

Answer 9

• It was concluded that each allele is inherited independent of each other as long as they are on different chromosomes
• In other words, inheriting one allele has no impact on the inheritance of another
• This means parents are just as likely to produce any of the four gametes

Question 10

Calculating Probabilities

Answer 10

• We can use the product law to determine the probability of two or more events occurring given that the events are independent of one another
• You simply multiply the two probabilities
• Like the “And Rule” you learn in grade 7/8 math