Complex Genetics: Extensions to Mendel

Question 1

3 ways complex genetics is different than Mendelian genetics

Answer 1

• More than 2 alleles are possible
• Dominance amount can be variable
• Sex chromosomes alter rates

Question 2

Probabilities can still be calculated using complex genetics it’s just….

Answer 2

the interpretation is different

Question 3

Explain what an allele is

Answer 3

An allele is one of a pair of genes that appear at a particular location on a particular chromosome and control the same characteristic, such as blood type or colorblindness.
ASK ABBY

Question 4

What are 5 different types of dominance used in complex genetics

Answer 4

co-dominance, incomplete dominance, epistasis, sex-linked, polygenetic

Question 5

Does dominance affect the transmission of alleles?? aka HOW punnet squares are formed??

Answer 5

NO

Question 6

Complete dominance

Answer 6

Hybrid resembles one of the two parents, depending on which was the dominant trait. All of mendel’s traits show complete dominance
Example-you have dominant R for a white mouse and r for a black mouse. When mixed together if you get Rr it’s going to be white. The mouse fully resembles only ONE of two parents

Question 7

Incomplete dominance

Answer 7

Hybrid resembles neither parent
Ex. So let’s say AA-equals red and aa-equals white cross breed with each other and you get 100% Aa’s which are Pink. That’s incomplete dominance.

Question 8

Codominance

Answer 8

Hybrid shows traits from both parents

Question 9

Codominance Example

Answer 9

Hybrid shows traits from both parents
Example:
Let’s say A controls those with A sugar and B is for B sugar. If you cross these two you’ll have an individual with both A AND B. COOOOODOMINANCE WOOOO

Question 10

There are six different genotypes that produce four blood types

Answer 10

I^A I^A A
I^A i

I^B I^B B
I^B i

I^A I^B AB

ii O

Question 11

Why do we care about blood types?

Answer 11

Because successful blood transfusions can only be made with matching blood types. The reason being is the body automatically makes antibodies for the sugars that are NOT present on their own red blood cells

Question 12

Polygenetic

Answer 12

two or more genes control a single phenotype

Question 13

Polygenetic Example

Answer 13

two or more genes control a single phenotype.

There’s this picture of an example. There are purple and white flowers. And for the flower to be purple it not only has to have a capital A, but a capital B as well to exhibit the color purple, OTHERWISE KNOWN AS, a single phenotype.

Question 14

Complementary Polygenetics

Answer 14

Basically what happens is for a particular phenotype to be expressed the enzymes like AA or Aa or some other letters have to be working, along with another enzyme, it’s partner, BB or Bb or some other letter in order to code for a particular phenotype. If the A’s aren’t working there’s no pigment. If the B’s aren’t working there’s no pigment. It doesn’t matter WHAT order. If one doesn’t work NEITHER DOES THE OTHER. AND you need at least one dominant allele of both genes in order for the pigment to work. That’s why I said AA or Aa, not aa. That results in a non-functional enzyme.

Question 15

Sex-linked traits

Answer 15

traits associated with X and Y chromosomes

Question 16

Would a woman ever have a trait on a Y chromosome?

Answer 16

No, because women have two XX’s they never deal with Y’s in general

Question 17

What’s the most prominent pattern of inheritance in sex-linked traits?

Answer 17

X-linked recessive

Question 18

why would X-linked dominant traits be more common in women?

Answer 18

Because if their father had a trait it automatically gets passed onto his offspring because he only has one X to contribute which is the contaminated one

Question 19

X-linked recessive traits are more common in?

Answer 19

MORE COMMON IN MEN

Question 20

X-linked dominant traits are more common in?

Answer 20

MORE COMMON IN WOMEN

Question 21

Epistasis

Answer 21

An allele at one gene masking the effects of another gene

A gene modifies another gene or multiple other genes

Question 22

Recessive Epistasis

Answer 22

Epistatic gene must be homozygous recessive to mask the other gene Example: Genotype ee masks the effect of all B genotypes

Question 23

Dominant Epistasis

Answer 23

Epistatic gene can be homozygous dominant or heterozygous to mask the other gene
Example:

Question 24

An interaction between non-allelic genes that results in the masking of expression of a phenotype is

Answer 24

epistasis