Human Genetics 6 & 7

Question 1

why is there diversity and patterns across globe of genetics

Answer 1

1. Most variation in Africa
2. Most other pops= subset of Africa
   - Migration out of Africa
3. // diversity= reflection of early migration history out of Africa

Question 2

describe genotypes of Rhesus blood groups

Answer 2

2 alleles
- D d
-D antigen = Rh+
d= null allele = Rh-

Question 3

what happens for detection of D antigen

Answer 3

A. Antibody > specifically target D protein on cell + sticks to surface
• Protein
• Anti-D
Agglutination (antibody sticking together=
• Lock and key mechanism structure
• Not coagulation

Question 4

describe haemolytic disease of newborn

Answer 4

child Rh+ but mother not, > mother produces immune response creating antibodies that destroy feats blood

Question 5

important genetic principals (4)

Answer 5

• Genes have multiple effects (pleiotropy)
• Effect of a gene varies in individuals (variable expression)
• Effect of gene depend on enviro (genotype-environment interaction)
• Several different genes have same effect (genetic heterogeneity)

Question 6

describe o a and b at dna level

Answer 6

• O group caused by deletion
• No sugars on surface on cell
• Like Rh but sugars instead of protein
• A + B = (genetic variations) single changes at nucleotide level= correspond to amino acids

Question 7

what typeof antibodies does abo have

Answer 7

naturally occurring

• A= anti B
• B= anti A
• o= anti a and b

Question 8

universal donor and receive

Answer 8

• Universal donor= O

* Universal receivers = AB

Question 9

2 reasons for different alleles in ABO blood groups

Answer 9

• reflect migration

- favourable for certain diseases

Question 10

whats HLA

Answer 10

Human Leucocyte antigens)

Antigens on white blood cells

Question 11

WHY ARE hla so diverse

Answer 11

• They differentiate ‘self’ and ‘non-self’
• Places beacon to kill invaded cells
• People present different forms of virus
• // harder for virus to escape if ca present all parts of virus