Module 10

Question 1

In seed shape what does the R gene make?

Answer 1

Makes starch branching enzyme

If it is a Dominant R allele —–> the enzyme turns glucose into branched starches

Question 2

How is the r allele different then the dominant R allele in seed shape?

Answer 2

R allele: Functional gene therefore proper starch production
r allele: Nonfunctional enzyme due to insertion of TE

Question 3

Why do r Allele seed shaped wrinkled?

Answer 3

Because a TE has inserted itself and disabled the gene that is able to turn glucose into branched starch, if the seed is unable to do that, seeds with too much glucose swell with water snd then wrinkle

Question 4

What is a truncated enzyme?

Answer 4

An enzyme that is nonfunctional, (there is no pigment production in this case)

Question 5

what is incomplete dominance?

Answer 5

heterozygote phenotype falls in between the phenotypes of the two homozygotes
Exx: A1A1 = red A1A2 = pink
A2A2 = white

Question 6

with incomplete dominance if the P generation is PP (dark purple) x pp (white) what would the offsprings be in f1?

Answer 6

All Pp (All light purple)
F2
1/4 PP = Dark purple
1/2 Pp = light purple
1/4 pp = white
1: 2 : 1 ratio

Question 7

What is codominance and how does it differ from incomplete dominance?

Answer 7

Heterozygote simultaneously expresses the phenotypes of both homozygotes (its not a mix of two colours into pink it would be white and brown spots in cattle)

Question 8

What is pleiotropy?

Answer 8

Where one gene affects several phenotypes

Question 9

What is an example of a pleiotropy in pea plants?

Answer 9

Anthocyanin pigment affects several phenotypes
Ex: R/_ controls the flower colour, leaf axil colour and seed colour

Question 10

What is antagonistic pleiotrophy?

Answer 10

one gene creates Alleles that can be both good and bad (think sickle cell)

Question 11

What is incomplete penetrance?

Answer 11

The genotype does not always produce the expected phenotype
-Due to effects of other genes and environmental factors

Question 12

What is polydactyly?

Answer 12

A condition caused by a dominat gene which makes you have an extra finger

Question 13

If polydactyly is caused by a dominant gene why do some people with the gene not have it?

Answer 13

If 38 of 42 humans with this allele are polydactylous, the gene has 38/40 x 100% = 90% penetrance (rate of expression of the gene)

Question 14

what is pentrance?

Answer 14

The rate of expression of the gene
Ex:
If 38/42 humans with this allele have the condition then 38/40 x 100% = 90% penetrance

Question 15

When do lethal alleles usually cause death?

Answer 15

Cause death in early development, often before birth
-Often recessive and rare in population

Question 16

Okay if
YY = lethal
Yy = live, be yellow
yy = live, be white
What is the ratio of the f1 gen?

Answer 16

1/4 YY (dead)
1/2 Yy (yellow)
1/4 yy (white)
So Y is domiannt for coat colour and recessive for causing death (meaning you need two of them YY)

Question 17

True or False: Many loci have > 2 alleles within a population

Answer 17

True but each diploid organism still has only 2

Question 18

What does IA and IB and i encode in human blood?

Answer 18

IA = encodes A antigen
IB = encodes B antigen
i = doesnt encode an antigen

Question 19

Where are antigens found?

Answer 19

Found on RBC surface

Question 20

What can patients not receive during a blood transfusion?

Answer 20

Patients can’t receive RBCS with new antigens

Question 21

What gene is responsible for determining which antigens are on your RBCs?

Answer 21

the ABO gene
-It attaches monosaccharides onto oligosaccarides on RBCS
Sugar (antigen) type —-> blood type

Question 22

True or False: IA and IB differ by a large amount of bps

Answer 22

False! They only differ by 7bp
i is the exact same as IA except it has 1 Bp deletion

Question 23

Who is dominant over whom for antigen alleles?

Answer 23

IA is dominant to i
IB is dominant to i
IA is codominant to IB

Question 24

If someone had both IA and IB genotype what would their blood type be?

Answer 24

AB blood because there codominant, they are both expressed together

Question 25

If you have A blood what is your potential genotype?

Answer 25

IAIA or IAi

Question 26

If you have a blood type of A what is your antigen tyoe and what is the antibodies made by the body?

Answer 26

Antigen type = A Antibodies made by body = Anti-B

Question 27

What do Antibodies in plasma do?

Answer 27

Attacks other antigens that is not the antigen that resides on the RBCS A = Blood Type A= Antigen Anti-B = antibodies in plasma -The body senses the B antigens as foreign and makes anti-B antibodies

Question 28

What blood type are universal recipients?

Answer 28

Type AB because they have both A and B antigens on their RBCS their body doesnt make any antibodies

Question 29

What is the genotype of type o?

Answer 29

ii -This means it has no antigens -It has both Anti-A and Anti-B They can donate to any recipient because they have no antigens that would make the other blood attack them

Question 30

If someone is type o who can they receive blood from?

Answer 30

Only from other type o -Because it has both Anti-A and Anti-B it would attack any other blood

Question 31

If the mother is Type A and the Father is Type O could they make a Type B baby?

Answer 31

NO! because the father is ii we could only create IAi or ii depending on the mothers genotype (IAIA or IAi) -If the mother had IB she would express codomaince and be type AB

Question 32

What is the Rhesus factor?

Answer 32

Additional blood factor that encodes a membrane protein RHD D allele encodes the D antigen on RBCS D/_ Rh+ D antigen present d/d Rh- D antigen absent

Question 33

If someone with AB blood type also had a D/d genotype what would happen?

Answer 33

It would be AB + If it had a d/d genotype is would be AB-