VRAAG 1 QUESTION 18

1
VRAAG 1 / QUESTION 1 8 A population of blesbok
(n234) contains 15 white blesbok. White
coloring is caused by the double recessive
genotype, "aa". Only one other allele is found at
this gene locus, and 31 of animals are
heterozygous. Do genotype frequencies in this
population conform to expected Hardy Weinberg
equilibrium? Assume that the critical value for
the X2test is 3.84. n Bevolking blesbokke
(n234) bevat 15 wit individue. Wit kleur in
blesbokke word veroorsaak deur die dubbele
resessiewe genotiepe aa. Net een alternatiewe
alleel kom by die geen voor, en 31 van diere is
heterosigote. Bepaal of die genotiep frekwensies
in hierdie bevolking aan verwagte Hardy Weinberg
ekwilibrium voldoen. Neem aan dat die kritieke
waarde vir die X2 toets 3.84 is.
2
AA 126 (0.538)
Genotypes
Aa 73 (0.312
aa 35 (0.149)
Allele frequencies
3
And actual expected numbers for each genotype
Expected frequency of genotype AA p²
(0.69)² 0.476 x 234 ½
111.41 ½
Expected frequency of genotype Aa 2pq
2(0.69)(0.31) 0.428 x 234 ½
100.11 ½
Expected frequency of genotype aa q²
(0.31)² 0.096 x 234 ½ 22.49 ½
4

1 or ½
16.211
5
X2 critical 3.84 X2 calculated
16.211 16.211 is larger than 3.84 1
The null-hypothesis - observed genotypic
frequencies do not differ from expected genotypic
frequencies is rejected.
Conclusion
The population is not in Hardy-Weinberg
equilibrium 1
6
VRAAG 2 / QUESTION 2 10 You are on an
airplane with 299 other passengers and crew
(5050 males and females). After an emergency,
the plane crash land (safely) on a deserted
island. No one finds you and you start a new
population totally isolated from the rest of the
world. Fifteen of the passengers carry (i.e. are
heterozygous for) the recessive allele for colour
blindness (c). S 0.4. The pilot is totally
colour blind, possibly explaining the crash. What
will be the frequency of this recessive allele
c - on your island in the next generation?
(Assuming everybody contributes to the next
generation). What will the frequency be 4
generations after the latter generation? Jy is
op n vliegtuig saam met 299 ander passasiers en
bemanningslede (5050 manlik en vroulik). Na n
insident doen die vliegtuig n noodlanding op n
eiland en almal oorleef. Julle word nooit weer
opgespoor nie en n nuwe bevolking ontstaan,
totaal geïsoleerd van die res van die wêreld.
Vyftien passasiers dra die resessiewe alleel vir
kleurblindheid (c). S 0.4. Die loods is
kleurblind, wat moontlik die ongeluk verklaar.Wat
sal die frekwensie van die resessiewe alleel c
wees in die volgende generasie? (Neem aan dat
almal tot die volgende generasie bydra). Wat sal
die frekwensie van c wees, 4 generasie na hierdie
generasie?
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Initial genotype frequencies n 300 CC
284/300 0.947 1 Cc 15/300 0.050 cc
1/300 0.003 1 Initial allele
frequencies C (CC) ½(Cc) 0.947 ½(0.05)
0.972 1 c (cc) ½(Cc) 0.003 ½(0.05)
0.028 1 Allele frequencies in next
generation p1 po / (1- sqo2) q1 1
p1 0.972 / 1 (0.4)(0.003) 1 1
0.973 0.973 1 0.027 1
8
p10 1 (t 1) qo / (1 tqo) 1
(4-1)(0.027) / 1 (4)(0.27) 1/1
0.976 1 OR use original p value 1 (t
1) qo / (1 tqo) 1 (5-1)(0.028) / 1
(5)(0.28) 0.976
Formula?
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VRAAG 3 / QUESTION 3 5 Explain what is
meant by correlated response, during selection
programs. Verduidelik wat bedoel word met
gekorroleerde reaksie tydens seleksie
programme. A change in one trait after selecting
for another trait. 1 Reasons - Pleiotropic
genes (every gene effects every trait) 1 -
Linkage disequilibrium 1 Negative outcome
weakening of selection response 1 Positive
outcome unexpected advantage, e.g. larger body
size larger litter size 1 (last 2 optional,
marks given for alternative explanations)
10
VRAAG 4 / QUESTION 4 5 Explain why a
plateau is often reached during selection
programs. Verduidelik waarom n plato soms
tydens seleksie programme bereik
word. Exhaustion of additive genetic
variance 1 all alleles affecting trait
fixed, lost or in eqwilibrium 1 No variation
no progress on selection 1 Artificial
selection opposed by natural selection (body size
vs. litter size) 1 Additive variation may
still be present (reverse selection.) 1
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VRAAG 5 / QUESTION 5 10 Consider two zoo
populations of zebra. In the one population,
allele frequencies at a given locus are A0.33,
B0.42 and C0.25. The second population has been
subjected to intensive but misguided management.
Allele B has disappeared from this population,
and all remaining individuals are heterozygous.
What is the genetic distance between these two
populations? Gestel daar is twee zebra
bevolkings in dieretuine. In die een bevolking is
die allele frekwensies A0.33, B0.42 en C0.25
by n gegewe lokus. Die tweede bevolking was
onderhewig aan intense maar swak beplande
bestuur. Alleel B het verdwyn en al die
oorblywende diere is heterosigote. Wat is die
genetiese afstand tussen die 2 bevolkings?
12
?
Genetic distance between populations 1 and
2 For Pop1 ?pix2 (0.33)2 (0.42)2 (0.25)2
0.348 1/1 For Pop2 ?pix2 (0.5)2
(0.5)2 0.5 1/1 And ?(pixpiy)
(0.33x0.5) (0x0.42) (0.25x0.25)
0.29 1/1
13
For Pop1 ?pix2 (0.33)2 (0.42)2 (0.25)2
0.348 For Pop2 ?pix2 (0.5)2 (0.5)2
0.5 And ?(pixpiy) (0.33x0.5) (0x0.42)
(0.25x0.25) 0.29
IN ?(pixpiy) / v (?pix2 )(?piy2) 0.29
/ v (0.348 x 0.5) 0.695 1/1 And genetic
distance -ln(IN) 1 -ln(0.695)
0.364 1
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VRAAG 6 / QUESTION 6 4 Explain why
deletions are a particularly harmful form of
mutation. Verduidelik waarom weglatings n
besonder skadelike vorm van mutasie is. Shifts
reading frame of the triplet code 1/1 Example
TAC-AAC-CAT becomes TCA ACC CA- 1 Different
Animo Acid(s) coded for 1 Malfunctioning
protein 1 Passed to next generation depending
on site of mutation 1
15
VRAAG 7 / QUESTION 7 9 Consider a
scenario with two islands. The sizes of two
populations on the two islands are Pop120,189
and Pop233,753 respectively. At a locus with 2
alleles, allele A occurs at a frequency of 0.35
in Pop1 and 0.71 in Pop2. a. Describe what will
happen to the frequency of allele A in Pop1 if,
in a once-off event, 3,256 animals move from Pop2
to Pop1. b. A number of individuals migrate
between the two populations, in line with the
island model of migration. Assume that these
population sizes are large enough to act as
infinitely large, and m0.12. What will be the
frequency of A in Pop1 after 9 generations? Geste
l daar is twee eilande. Die bevolkingsgroottes is
onderskeidelik Bev120,189 en Bev233,753. By n
locus met twee allele, kom alleel A voor teen n
frekwensie van 0.35 in Bev1 en 0.71 in Bev2. a.
Wat sal gebeur met die frekwensie van allele A in
Bev1 as 3,256 diere eenmalig van Bev2 na Bev1
migreer? b. n Aantal individue migreer tussen
die twee bevolkings, volgens die eiland model van
migrasie. Neem aan dat die bevolkingsgroottes
groot genoeg is om as oneindig groot beskou te
word, en m0.12. Wat sal die frekwensie van
alleel A in Bev 1 wees na 9 generasies?
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A. For given Pop 1, n 20,189 3,256 animals
from Pop 2 emigrates to Pop 1 q1 was 0.35 q2
0.71 m n2 / (n1 n2) 3,256 / (20,189
3,256) 1 0.139 1 The new frequency of q
after migration (qm) is qm m(q2 - q1)
q1 0.139 (0.71 0.35) 0.35 1/1
0.40 1
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B. With movement of migrants in both directions,
the frequency of A in migrants (0.71 0.35) /
2 0.53 1/1 For Pop that started with A
0.35 P9 0.53 (0.35 0.53)(1 - 0.12)9
1 0.483 1
pt p (po p)(1 m)t
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VRAAG 8 / QUESTION 8 5 Briefly discuss the
similarities and differences between natural
selection, artificial selection and mutation.
Beskryf kortliks die ooreenkomste en verskille
tussen natuurlike seleksie, kunsmatige seleksie
en mutasie.
Natural selection Natural process, selection
for fittest in given environment, based on
naturally occurring genetic diversity. 2 Artifi
cial selection Manmade, for desirable character
state, based on naturally occurring genetic
diversity. 2 Mutation NEW variation. 1
But.
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• VRAAG 9 / QUESTION 9 9
• Briefly define the following terms / Verklaar die
  volgende terme
• Knock out techniques / uitklop tegnieke(3)
• Delete/inactivate a region of DNA 1, to prevent
  it from being expressed (transcribed) 1. Reason
  to target specific genes and determine
  function. 1
• b. Disruptive selection / Diversifiserende
  seleksie(2)
• Selection for extremes (homozygostes) 1
• against heterozygote. 1

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VRAAG 9 / QUESTION 9 continued.. Briefly
define the following terms / Verklaar die
volgende terme c. Selection response /
seleksie respons (2) Difference between - the
mean of the parental geberation and 1 - mean
of the offspring from selected parents 1 d.
Assortative mating (positive) / Assortatiewe
paring (positief) (2) When same phenotypes
attract, e.g. human mate choice based on similar
IQ. 1/1