Download Document

CAMPBELL BIOLOGY IN FOCUS
Urry • Cain • Wasserman • Minorsky • Jackson • Reece
11
Mendel and the
Gene Idea
Lecture Presentations by
Kathleen Fitzpatrick and Nicole Tunbridge
© 2014 Pearson Education, Inc.
© 2014 Pearson Education, Inc.
© 2014 Pearson Education, Inc.
Figure 11.1
© 2014 Pearson Education, Inc.
Concept 11.1: Mendel used the scientific approach
to identify two laws of inheritance
 _________________________________________
_________________________________________
© 2014 Pearson Education, Inc.
Figure 11.2
Technique
1
2
Parental
generation
(P)
3
Stamens
Carpel
4
Results
5
First filial
generation
offspring
(F1)
© 2014 Pearson Education, Inc.
 _________________________________________
_________________________________________
© 2014 Pearson Education, Inc.
 __________________________________________
________________________________________
 _________________________________________
 __________________________________________
________________________________________
 __________________________________________
________________________________________
© 2014 Pearson Education, Inc.
Figure 11.3-3
Experiment
P Generation
(true-breeding
parents)
Purple flowers
White flowers
F1 Generation
(hybrids)
All plants had purple flowers
Self- or cross-pollination
F2 Generation
705 purple-flowered 224 white-flowered
plants
plants
© 2014 Pearson Education, Inc.
Table 11.1
© 2014 Pearson Education, Inc.
Table 11.1a
© 2014 Pearson Education, Inc.
Table 11.1b
© 2014 Pearson Education, Inc.
Mendel’s Model
 _________________________________________
 _________________________________________
_________________________________________
 _________________________________________
_________________________________________
 _________________________________________
 _________________________________________
_________________________________________
(and end up in different gametes)

© 2014 Pearson Education, Inc.
Figure 11.5-3
P Generation
Purple flowers White flowers
Appearance:
PP
pp
Genetic makeup:
p
P
Gametes:
F1 Generation
Appearance:
Genetic makeup:
Gametes:
Purple flowers
Pp
½ p
½ P
Sperm from
F1 (Pp) plant
F2 Generation
P
p
PP
Pp
Pp
pp
P
Eggs from
F1 (Pp) plant
p
3
© 2014 Pearson Education, Inc.
:1
 _________________________________________
 _________________________________________
© 2014 Pearson Education, Inc.
Figure 11.6
3
Phenotype
Genotype
Purple
PP
(homozygous)
Purple
Pp
(heterozygous)
1
2
1
© 2014 Pearson Education, Inc.
Purple
Pp
(heterozygous)
White
pp
(homozygous)
Ratio 3:1
Ratio 1:2:1
1
Test Cross
• _____________________________________
_____________________________________
• _____________________________________
_____________________________________
© 2014 Pearson Education, Inc.
Figure 11.7
Technique
Dominant phenotype,
unknown genotype:
PP or Pp?
Recessive phenotype,
known genotype:
pp
Predictions
If purple-flowered
parent is PP
Sperm
p
p
If purple-flowered
parent is Pp
Sperm
p
p
or
P
P
Pp
Eggs
Pp
Eggs
P
Pp
pp
pp
p
Pp
Pp
Results
or
All offspring purple
© 2014 Pearson Education, Inc.
Pp
½ offspring purple and
½ offspring white
Figure 11.8
Experiment
YYRR
P Generation
yyrr
Gametes YR
yr
F1 Generation
YyRr
Hypothesis of
dependent assortment
Predictions
Hypothesis of
independent assortment
Sperm
or
Predicted
offspring in
F2 generation
¼ YR ¼ Yr ¼ yR ¼ yr
Sperm
½ YR ½ yr
¼ YR
½ YR
Eggs
½ yr
YYRR YyRr
YyRr
¾
yyrr
¼ Yr
Eggs
¼ yR
YYRR YYRr
YyRR YyRr
YYRr
YYrr
YyRr
Yyrr
YyRR YyRr
yyRR
yyRr
YyRr
yyRr
yyrr
¼
Phenotypic ratio 3:1
¼ yr
9
16
3
16
Yyrr
3
16
1
16
Phenotypic ratio 9:3:3:1
Results
315
© 2014 Pearson Education, Inc.
108
101
32
Phenotypic ratio approximately 9:3:3:1
 _________________________________________
 __________________________________________
________________________________________
 __________________________________________
__________________________________________
_______________________________________
© 2014 Pearson Education, Inc.
Degrees of Dominance
 _________________________________________
 _________________________________________
 _________________________________________
© 2014 Pearson Education, Inc.
Figure 11.10-3
P Generation
Red
CRCR
White
CWCW
Gametes
CR
CW
Pink
CRCW
F1 Generation
Gametes ½ CR ½ CW
Sperm
½ CR ½ CW
F2 Generation
½ CR
Eggs
CRCR
CRCW
CRCW
CWCW
½ CW
© 2014 Pearson Education, Inc.
Multiple Alleles
 Most genes exist in populations in more than two
allelic forms
 For example, the four phenotypes of the ABO blood
group in humans are determined by three alleles of
the gene: IA, IB, and i.
 The enzyme (I) adds specific carbohydrates to the
surface of blood cells
 The enzyme encoded by IA adds the A carbohydrate,
and the enzyme encoded by IB adds the B
carbohydrate; the enzyme encoded by the i allele
adds neither
© 2014 Pearson Education, Inc.
Figure 11.11
(a) The three alleles for the ABO blood groups and their
carbohydrates
Allele
Carbohydrate
IB
IA
i
none
B
A
(b) Blood group genotypes and phenotypes
Genotype
IAIA or IAi
IBIB or IBi
IAIB
ii
A
B
AB
O
Red blood cell
appearance
Phenotype
(blood group)
© 2014 Pearson Education, Inc.
Extending Mendelian Genetics for Two or More
Genes
 ________________________________________
________________________________________
© 2014 Pearson Education, Inc.
Figure 11.12
BbEe
BbEe
Sperm
¼ bE
¼ BE
¼ Be
¼ be
Eggs
¼ BE
BBEE
BbEE
BBEe
BbEe
BbEE
bbEE
BbEe
bbEe
BBEe
BbEe
BBee
Bbee
BbEe
bbEe
Bbee
bbee
¼ bE
¼ Be
¼ be
9
© 2014 Pearson Education, Inc.
:
3
: 4
Polygenic Inheritance
 _________________________________________
_________________________________________,
 _________________________________________
_________________________________________
© 2014 Pearson Education, Inc.
Figure 11.13
AaBbCc
AaBbCc
Sperm
1
1
1
1
1
Eggs
1
1
1
1
8
1
8
1
1
8
8
1
8
1
1
8
8
8
8
8
8
8
8
8
8
Phenotypes:
Number of
dark-skin alleles:
© 2014 Pearson Education, Inc.
1
8
1
64
0
6
64
1
15
64
2
20
64
3
15
64
4
6
64
5
1
64
6
1
64
Describing
Continuous
Variation
© 2014 Pearson Education, Inc.
Fig. 11-20, p.181
Nature and Nurture: The Environmental Impact
on Phenotype
 ________________________________________
________________________________________
© 2014 Pearson Education, Inc.
Temperature Effects
on Phenotype
• This Rabbit is homozygous for
allele producing heat-sensitive
version of an enzyme in
melanin-producing pathway
• Melanin is produced in cooler
areas of body
Figure 11.16
Page
179
© 2014 Pearson Education, Inc.
© 2014 Pearson Education, Inc.
This Siamese cat, raised in a cold
environment in Moscow in the
late 20s, developed a relatively
dark coat. An area on his
shoulder was shaved, and the cat
wore a warm jacket while the fur
was growing back. When the
shaved hair grew back in, it was
white, the same color as the cat's
belly, due to the increased
temperature under the jacket.
This was not due to scarring, as
the hair grew in normally colored
later.
© 2014 Pearson Education, Inc.
Figure 11.14
Key
Male
Female
1st generation
(grandparents)
Affected
male
Affected
female
Mating
Offspring, in
birth order
(first-born on left)
Ff
Ww
ww
2nd generation
(parents,
aunts, and
uncles)
Ww ww ww Ww
ww
Widow’s peak
Ww
ww
FF or ff
Ff
ww
No widow’s peak
(a) Is a widow’s peak a dominant or recessive trait?
© 2014 Pearson Education, Inc.
ff
Ff
Ww
3rd generation
(two sisters)
WW
or
Ww
Ff
Attached
earlobe
ff
Ff
Ff
ff
FF
or
Ff
ff
Free
earlobe
(b) Is an attached earlobe a dominant
or recessive trait?
Figure 11.15
Parents
Normal
Normal
Aa
Aa
Sperm
A
a
A
AA
Normal
Aa
Normal
(carrier)
a
Aa
Normal
(carrier)
aa
Albino
Eggs
© 2014 Pearson Education, Inc.
Sickle-Cell Disease: A Genetic Disorder with
Evolutionary Implications
 ___________________affects one out of 400
African-Americans
 __________________________________________
________________________________________
Symptoms include physical weakness, pain, organ
damage, and even paralysis
 _________________________________________,
© 2014 Pearson Education, Inc.
Autosomal
Dominant
Inheritance
example…
Achondroplasia
© 2014 Pearson Education, Inc.
Fig. 12-5, p.190
Achondroplasia
 _________________________________________
 _________________________________________
 _________________________________________
 _________________________________________
© 2014 Pearson Education, Inc.
Huntington
Disorder
 _______________
_______________
 _______________
_______________
_______________
_______________
 _______________
_______________
 _______________
_______________
_______________
_______________
© 2014 Pearson Education, Inc.
Hutchinson-Gilford Progeria
 _________________________________________
 No evidence of it running in families
 _________________________________________
 _________________________________________
 Usually causes death in early teens
© 2014 Pearson Education, Inc.
Hutchinson-Gilford Progeria
© 2014 Pearson Education, Inc.
Fig. 12-7, p.191
The Y Chromosome
 _________________________________________
 _________________________________________
_________________________________________
© 2014 Pearson Education, Inc.
© 2014 Pearson Education, Inc.
Fig. 11-21, p.183
© 2014 Pearson Education, Inc.
Fig. 11-21, p.183