Transcript Ch. 4. Modern Genetics

Cells and Heredity
Chapter 4 Modern Genetics
Section 1 Human Inheritance
Section 1 Human Inheritance:
Objectives





To explain what multiple alleles are.
To explain why some human traits show
a large variety of phenotypes.
To explain how environmental factors can alter the
effects of a gene.
To explain what determines sex and why some sex
linked traits are more common in males than in
females.
To describe how geneticists use pedigrees.
Section 1 Human Genetics Vocab
 1.
multiple alleles
Three or more forms of a gene that
code for a single trait.
 2.
sex-linked gene
A gene that is carried on the X or Y
chromosome
 3.
carrier
A person who has one recessive allele
for a trait and one dominant allele, but
does not have the trait.
 4.
pedigree
A chart or “family tree” that tracks
which members of a family have a
particular trait.
Notes
 1.
Chromosomes
____________ exists in pairs.
 2.
Two traits controlled by many genes
are:
– A.
height
– B.
skin color
 3.
Three environmental factors that can
effect height are:
–A
Lack of protein
–B
Lack of minerals
–C
Lack of vitamins
 4.
23 pairs of
There are __________
chromosomes in each body cell.
XY
Males have the ______
combination
of chromosomes, while females have the
XX
_______
combination
 5.
sperm
The _________
determines the
gender of the offspring.
 6.
 7.
Males
________ are more likely to have a
sex-linked trait that is controlled by a
recessive
______________ allele.
Cells and Heredity
Chapter 4 Modern Genetics
Section 2 Human Genetic
Disorders
Section 2 Human Genetic
Disorders: Objectives
 To
describe the causes and symptoms
of four human genetic disorders
 To explain how genetic disorders are
diagnosed.
Vocab
 5.
genetic disorder
An abnormal condition that a person
inherits through genes or chromosomes.
 6.
amniocentesis
A technique by which a small amount of
the fluid that surrounds a developing
baby is removed; the fluid is analyzed to
determine whether the baby will have a
genetic disorder.
 7.
karyotype
A picture of all the chromosomes in a
cell arranged in pairs.
Notes
Genetic Disorders
______________________
are
mutations
caused by _____________________,
or changes in a person’s
DNA
______________.
 1.
 2.
 A.
Describe each order and its cause
Cystic Fibrosis
– Affect-
Causes think mucus to build up in a
person’s lungs and intestines
– Cause-
A mutation that is carried on a
recessive allele.
 B.
Sickle-Cell
– Affect- Sickle shaped red blood cells that
can not carry as much oxygen as
normal blood cells
– Cause-
A mutation that affects the
production of hemoglobin, a protein
in red blood cells that carries
oxygen
 C.
Hemophilia
– Affect- A disorder in which a person’s blood
clots very slowly or not at all
– Cause- People with the disorder do not
produce one of the proteins needed
for normal blood clotting
 D.
Down Syndrome
A distinctive physical appearance, some
– Affect- degree of mental retardation, heart defects.
Many people with down syndrome lead
full lives.
– Cause-
A person’s cells have an extra copy
of chromosome 21.
Cells and Heredity
Chapter 4 Modern Genetics
Section 3 Advances in
Genetics
Section 3 Advances in Genetics:
Objectives
 To
describe three ways in which people
have developed organisms with desired
traits.
 To explain how DNA fingerprinting is
used
 To state the goal of the Human Genome
Project.
Vocab
 8.
Selective breeding
The process of selecting a few
organisms with desired traits to serve
as parents of the next generation.
 9.
Inbreeding
A selective breeding method in which
two individuals with identical or similar
sets of alleles are crossed.
 10.
Hybridization
A selective breeding method in which
two genetically different individuals are
crossed.
 11.
Clone
An organism that is genetically identical
to the organism from which it was
produced.
 12.
Genetic engineering
The transfer of a gene from the DNA
of one organism into another organism,
in order to produce an organism with
desired traits.
 13.
Gene therapy
The insertion of working copies of a
gene into the cells of a person with a
genetic disorder in an attempt to
correct the disorder.
 14.
Genome
All of the DNA in one cell of an
organism.
Notes
 1.
Two examples of selective breeding
– A.
Dairy cows are bred to produce larger
quantities of milk
– B. Varieties of fruits and vegetables that are
bred to resist diseases
 2.
Two examples of inbreeding
–A
–B
Some purebred horses
Purebred dogs, such as Labrador retrievers
and German sheperds
 3.
One problem with inbreeding is:
Increases the chances of inheriting alleles
that lead to genetic disorders.
 4.
Two examples of hybridization
– A. Crossing corn that produces many kernels
With corn that is resistant to diseases
– B.
A mule coming from the cross of a mare and
a donkey. The mule has the courage, stamina,
and surefootedness of the donkey
with the strength of a horse
 5.
A common example of cloning is
*To make a “cutting” from a plant. The cutting can
grow into a new plant
hair
DNA samples from _______,
skin
blood can be used to
______,
and _____
identify a person.
 6.
 7.
No two people, except
Identical twins
_______________
have the same
DNA.