Observation

Some candidates performed poorly in this question because they were trying to merge the two laws of Mendel rather than separate them as first law and second law.
In (a) (ii), candidates were giving general applications of genetics rather than in medicine only.
In (a) (iii), candidates could not give correct answers to the disadvantages of inbreeding and were writing things that did not correspond to the question asked.
Some candidates could define evolution but could not distinguish between convergent and divergent evolution may be because it is always taught at the tail end hence, this aspect of the syllabus is hardly covered by the teacher.

The expected answers are:

(a) (i) Mendel’s laws of inheritance
First law/law of segregation                                                                                       
States that a pair of alleles/genes of contrasting character; segregates during gamete formation so that only one allele/gene enters a single gamete.                 

Second law/law of independent assortment                                                              
States that of a pair of alleles/genes of contrasting character; segregates independently; and combines randomly/distribute itself; with either of another pair of alleles/ genes.                                                                                                                                                                                
(ii) Applications of genetics in medicine

• Screening blood for transfusion;
• Determining paternity/ parentage;
• Marriage counselling for genetic disorders;
• Production of certain drugs/insulin;
• Sex selection in babies;
• Cloning of cells;
• Test-tube babies/ in-vitro fertilization;
• Organ transplant.
• Analysis of blood in crime detection.

                                                                                                                 
(iii) Disadvantages of inbreeding

• Loss of reproductive vigour/potency;
• Susceptibility to disease;
• Limited gene pool/lack of varieties;
• Inability to withstand environmental changes;
• Replication /retention of undesirable traits.                                      

(b) (i) Evolution
The process of development of complex organisms; from simple forms; over a long period of time; and results in the origin of new species.                                      

      (ii)  Convergent and divergent evolution
Convergent evolution produces similar structures in organisms; that have evolved from different unrelated ancestors; while divergent evolution produces modification of structures in organisms that have evolved from a common ancestor; due to adaptation to environmental changes.