Question

1. What is the fitness (W) value?
   1. It determines how well an organism reproduces
   2. It determines how well an organism makes gametes of a particular genotype
   3. It indicates how strong an organism is
   4. All of the above

In a population of Austrians, the frequency of alleles determining the ABO blood type groups were estimated to be:

            I^A = 0.20

I^B = 0.15

I^O = 0.65

1. What is the expected genotypic frequency for AO?
   1. .26
   2. .85
   3. .13
   4. .50
2. If the fitness value (W) of I^OI^O was 1.0 and for all other genotypes W = 0.85, what would happen in future generations?
   1. The frequency of I^O would increase
   2. The frequency of I^O would decrease
   3. The frequency of I^A and I^B would increase
   4. None of the above

Answer 1

Question 1

ans:a

fitness value simply represent the rate of survival or rate of reproduction. only fittest organisam can produce viable progency. Their frequency will be more in the population.

ans: how well an organisam reproduce.

question 2

ans:a

Finding genotype frequency

The some of all allele in a population will be =1 or = 100%

consider if there was only 2 allele namely p and q in a human population , p+q = 1 (HARDY WEIINBERG formula)

the frequency = ( p+q )2 (since human hav dipolid chromosome its raised to power of 2, if triplloid raised to 3 etc)

on expanding p2 + q2+ 2pq

p2 represent frequency of haploid p ie PP

q2 represent frequency of haploid q ie QQ

2pq represent frequency of hetrozygus ie PQ

since there are 3 allele here the calculation is slightly different

Blood groups exhibit two main properties 1. complete dominance 2. co dominance

ie. if we are looking for the possible combination inallele : A B O

there will be 6 different combination : AA, AB, AO, BA, BB, BO, OO

but we knw we only have 4 blood groups this is because 1. A and B exhibit COMPLETE DOMIANCE over O

  2. A and B also exhibit CO DOMINANCE

ie we have ( 6 genotypes , 4 blood group, 3 allele )

on formulating equation : said before adding up all allele frequency raised to the power of 2 (diploid chromosome)

GENOTYPIC FREQUENCY = (A+B+O)2  

on expanding = A2+ B2 +O2 + 2AB + 2AO + 2BO ( Frequency A = A2,B=B2,O=O2,AO=2AO,AB=2AB,BO=2BO)

we are asked for frequency of AO

FREQUENCY of AO = 2AO = 2 * .2* .65 = .26

but if we require the frequency  of A blood group ,

pick up both AA and AO from equation which makes group blood group  A

frequency A = A2 + 2AO

on computing the values we get frequency of type AO.

Question 3

ans:a

since the fitness value of IO is high is more capable to produce viable progeny than the rest so

ans: Frequency of IO would increase.