Unit 3 IP Genetics (DNA, Mutations, Cell Division, Protein Synthesis)

Part IA

Completed Punnett Square

A o

A AA Ao

B AB Bo

1 . The possible blood types represent possible phenotypes for the genotypes produced by the pairing of the two genotypes . The possible blood types are A , B and AB in this case

2 . The Punnett Square shows that two out of four possible combinations have an A phenotype . AB and B blood types are each produced by one genotype out of four . Translated to percentages , this means that the offspring has a 50 chance of being born

as a blood type A and a 25 chance of being born as an AB or B

3 . The Punnett Squares show that the only bloodtype which is 'nt possible is an O blood type

PartIB

1st Punnett Square for AB and B

B O

A AB Ao

B BB Bo

2nd Punnett Square for AB and B

B B

A AB AB

B BB BB

1 . The there are three possible blood types - A , B , and AB

2 . From the two Punnett squares , we see that there are eight possible genotypes . Three out of these genotypes have a phenotype of an AB blood type . Four genotypes will produce a B phenotype and one genotype out will produce an A phenotype . B is the most likely phenotype with 50 followed by AB with 37 .5 probablilty and A is last with a probability of 12 .5

3 . The only impossible blood type in our genotype pairing is an O blood type

Part II-1

The genetic variation between members of a population is a special offshoot of sexual reproduction . Unlike asexual reproduction wherein the offspring is genetically similar or even completely alike to its parents , offspring borne out of sexual reproduction are inherently different genetically from their parents . This is firstly because the genetic material of the offspring is a result of the Mendelian combination of the genes of the mother and father

Meiosis is also another way of driving genetic diversity . Meiosis is a form of cellular division in which the organelles replicate and divide accordingly between two daughter cells . The main difference between meiosis and mitosis is the pesence of a crossover step in the replication of the DNA in meiosis . In crossover , the chromosomes (which are formed by long strands of genetic material ) exchange sections of their DNA . The result is that each haploid daughter cell is unique Meiosis is the method by which sexual organisms become gametes , the genetic material for each parent is unique even at the cellular level This means that no two gametes of the father and mother are genetically alike due to meiosis

Part II-2 . One particular kind of genetic dis is sickle cell anemia . Sickle cell anemia is a disease which results in the red blood cells of the affected person being out of shape . Instead of being normally round cells , the red blood cells of a sickle cell anemia patient are elongated and bent out of shape similar to a sickle - hence...