Download Modern Genetics - Solon City Schools

Modern Genetics
Chapter 4
1
Human Inheritance

Some human traits are
controlled by single
genes with two alleles,
and others by single
genes with multiple
alleles. Still other traits
are controlled by many
genes that act together.
2
The Sex Chromosomes



Sex chromosomes are
one of 23 pairs of
chromosomes in each
body.
The sex chromosomes
carry genes that
determine whether a
person is male or female.
They also carry genes
that determine other
traits.
3
Sex-Linked Genes


Genes on the X and Y
chromosomes are
often called sexlinked genes.
A carrier is a person
who has one
recessive allele for a
trait and one
dominant allele.
4
Sex-Linked Traits




Colorblindness
Male patterned
baldness.
Hemophilia.
Duchene Muscular
Dystrophy.
5
Environment

Many of a person’s
characteristics are
determined by an
interaction between
genes and the
environment.
6
Human Genetic Disorders

A genetic disorder is
an abnormal condition
that a person inherits
through genes or
chromosomes.
 Cystic
Fibrosis
 Sickle-Cell Disease
 Hemophilia
 Down Syndrome
7
Genetic Disorders


Some genetic
disorders are caused
by mutations in the
DNA of genes.
Other disorders are
caused by changes in
the overall structure
or number of
chromosomes.
8
Pedigrees

A pedigree is a chart
of “family tree” that
tracks which
members of a family
have a particular trait.
9
Managing Genetic Disorders


Karyotype is a picture of
all the chromosomes in a
cell.
Genetic counseling helps
couples understand their
chances of having a child
with a particular genetic
disorder.
10
Dealing with Genetic Disorders



Medical Care.
Education.
Job Training.
11
Advances in Genetics



Selective breeding.
Cloning.
Genetic engineering.
12
Selective Breeding


Inbreeding involves
crossing two
individuals that have
similar characteristics.
Hybridization is the
cross between two
genetically different
individuals.
13
Cloning

A clone is an
organism that has
exactly the same
genes as the
organism for which it
was produced.
14
Genetic Engineering

Genetic engineering is
when genes from one
organism are transferred
into the DNA of another
organism.




Bacteria.
Cows.
Gene therapy.
Genetically altered crops.
15
Education About Genetics


A genome is all the DNA
in one cell of an
organism.
The main goal of the
Human Genome Project
has been to identify the
DNA sequence of every
gene in the human
genome.
16
Paramecia usually reproduce asexually. Fish reproduce
sexually. Suppose the environmental conditions in the
lagoon change. What advantage will the fish population
have over the paramecium population?
1
2
3
4
5
6
7
8
9
10
21
22
23
24
25
26
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30
du
ct
io
n
Se
xu
al
re
pr
o
du
ct
io
n
pr
o
re
Se
xu
al
0%
...
0%
...
0%
du
ct
io
n.
..
re
3.
Se
xu
al
2.
1.
Se
xu
al
re
pr
o
pr
o
du
ct
io
n.
..
0%
4.
1. Sexual reproduction produces
offspring that are identical to the
parents.
2. Sexual reproduction decreases the
genetic variability in the fish
populations.
3. Sexual reproduction limits the
spread of harmful characteristics in
fish populations.
4. Sexual reproduction allows
populations to adapt to new
conditions over fewer generations.
:10
11
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20
17
What is one advantage of sexual
reproduction?
4.
1
2
3
4
5
6
7
8
9
10
21
22
23
24
25
26
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qu
i..
...
w
re
lo
sn
ot
do
e
do
e
all
0%
al
sf
or
ow
sn
ot
.
qu
i..
0%
.
0%
di
v.
..
0%
re
3.
sn
ot
2.
does not require a
lot of calories
allows for diversity
does not allow for
diversity
does not require
two organisms
do
e
1.
:10
11
12
13
14
15
16
17
18
19
20
18
What is one advantage of asexual
reproduction?
0%
...
o
w
w
lo
re
q
ui
re
st
al
do
es
no
t
sf
or
ow
0%
d.
..
0%
di
v.
..
lo
t..
.
all
4.
0%
sa
3.
ui
re
2.
requires a lot of
calories
allows for diversity
does not allow for
diversity
requires two different
organisms
re
q
1.
:10
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2
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8
9
10
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19
Which of the following is not an example of
asexual reproduction?
0%
0%
0%
g
di
sp
er
sa
l
Bu
dd
in
g
of
s. .
.
0%
at
in
4.
m
3.
n
2.
Budding
dispersal of spores
fission
mating
fis
sio
1.
:10
1
2
3
4
5
6
7
8
9
10
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29
30
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12
13
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17
18
19
20
20
How has sexual reproduction enhanced a
species’ chance for survival?
Se
x
ua
l
re
p
ro
du
. ..
0%
ro
du
. ..
ua
l
Se
x
Se
x
ua
l
0%
re
p
ro
du
. ..
0%
re
p
ro
du
. ..
4.
0%
re
p
3.
ua
l
2.
Sexual reproduction produces
offspring with unique traits.
Sexual reproduction always
produces offspring that are
identical.
Sexual reproduction does not
allow for genetic variation.
Sexual reproduction between
two different species produces
offspring that can not
reproduce.
Se
x
1.
:10
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5
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8
9
10
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19
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21
From whom does an offspring get its traits?
1.
2.
3.
4.
Mom
Dad
both a and b
neither a nor b
:10
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5
6
7
8
9
10
21
22
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29
30
11
12
13
14
15
nd
b
or
...
0%
16
17
an
ne
ith
er
3
bo
th
2
0%
aa
M
om
1
0%
Da
d
0%
18
19
20
22
Which of the following terms describe the
appearance of the organism?
1
2
3
4
5
6
7
8
9
10
21
22
23
24
25
26
27
28
29
30
11
12
13
14
0%
15
16
yp
e
he
t
er
no
t
ph
e
0%
oz
yg
ou
s
0%
us
:10
0%
ho
m
oz
yg
o
5.
0%
yp
e
4.
Ge
no
t
3.
le
2.
Allele
Genotype
homozygous
phenotype
heterozygous
Al
le
1.
17
18
19
20
23
Which term describes a trait that is always
expressed when present?
2
3
4
5
6
7
8
9
10
21
22
23
24
25
26
27
28
29
30
11
12
13
14
ge
n
15
16
17
0%
es
pe
ot
y
in
an
do
m
1
0%
siv
e
0%
re
c
0%
t
4.
:10
yp
e
3.
no
t
2.
dominant
genotype
phenotype
recessive
ph
e
1.
18
19
20
24
Which term describes two of the same
allele?
:10
4
5
6
7
8
9
10
21
22
23
24
25
26
27
28
29
30
11
12
13
14
15
0%
16
17
0%
siv
e
oz
yg
ou
s
3
er
2
0%
he
t
1
do
m
in
an
t
0%
es
4.
18
re
c
3.
us
2.
dominant
heterozygous
homozygous
recessive
ho
m
oz
yg
o
1.
19
20
25
Given the genotype Bb, B is dominant for
brown eyes and b is recessive for blue eye, what
is the genotype and phenotype?
1
2
3
4
5
6
7
8
9
10
21
22
23
24
25
26
27
28
29
30
11
12
13
14
15
16
17
sb
ro
...
Ho
m
oz
yg
ou
sb
lu
oz
yg
ou
0%
...
0%
...
0%
oz
yg
ou
sb
...
0%
Ho
m
4.
:10
He
te
r
3.
oz
yg
ou
sb
2.
Heterozygous blue
eyes
Heterozygous brown
eyes
Homozygous blue
eyes
Homozygous brown
eyes
He
te
r
1.
18
19
20
26
Two adults decide to have a baby. If one parent
has brown eyes (BB), which is a dominant trait and
the other parent has blue eyes (bb), which is a
recessive trait, what is the probability that they will
have a baby with blue eyes?
100%
75%
50%
25%
0%
0%
10
0%
5.
1
2
3
4
5
6
7
8
9
10
21
22
23
24
25
26
27
28
29
30
11
12
13
14
0%
15
0%
16
0%
17
18
0%
0%
4.
:10
25
%
3.
50
%
2.
75
%
1.
19
20
27
A red four o’clock flower was crossed with a white
four o’clock flower. With Incomplete dominance
as a factor, what is the phenotype of the offspring?
1.
2.
3.
4.
100% red
100% white
50% red, 50% white
100% pink
:10
0%
0%
d
0%
10
re
0%
10
w
hi
te
d
%
50
1
2
3
4
5
6
7
8
9
10
21
22
23
24
25
26
27
28
29
30
11
12
13
14
15
0%
16
re
0%
,5
w
0%
...
17
0%
10
18
pi
nk
19
20
28
What is the phenotype of the F1 generation from
the Punnett square?
%
75
50
T
ta
l
l,
25
%
...
l,
10
0%
0%
50
%
ta
10
0%
0%
...
0%
T
ll
T
0%
ta
l
4.
%
3.
t
2.
:10
100% tall
100% short
50 % tall, 50% short
75 % tall, 25% short
sh
or
1.
t
1
2
3
4
5
6
7
8
9
10
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22
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25
26
27
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29
30
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20
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