By Chrissy, Matthew, Louise, and Savannah
Pre-assessment
Define gene and allele.
2. What does homologous chromosome
mean?
3. What is one thing eukaryote
chromosomes are made of?
4. Define gene mutation.
5. What is sickle cell anemia?
6. What is the purpose of meiosis?
1.
4.1.1

Eukaryote chromosomes are made of
DNA and protein.
 This is because chromosomes in a
Eukaryote are found in a nucleus.
 Chromosomes contain DNA and protein.
4.1.2 Genes

Definition- a unit of heredity in a living
organism
 Located in DNA
 Controls a specific characteristic (example-
eye color)
 Occupies a location on the chromosomes
called a locus
4.1.2 Allele

Definition- a specific form of a gene
 Differs from other alleles by one or a few
bases only
 Occupies the same gene locus as other
alleles of the gene
4.1.2 Genome

Definition- the total genetic material of
an organism
 Cell or organism
 Human genome project
4.2.1 Gene Mutation

Definition- a permanent change in the
genetic makeup of an organism
 Can affect only one nucleotide or multiples
 Occur in two ways
○ Inherited from a parent
○ Acquired during a person’s lifetime
 Ex. Manx cat
4.1.4 Sickle Cell Anemia

Sickle Cell Anemia is a disease passed
down through heredity that is caused by
a base substitution mutation in DNA
 Mutation occurs during transcription and
translation
 Glutamic acid is replaced by Valine
 GAG mutates to GTG causing sickly, sickle
shaped red blood cells
4.2.1 Meiosis

Meiosis is a reduction division of a
diploid nucleus to form haploid nuclei
 The product is 4 identical sex cells
 Haploid: Cells used in sexual reproduction.
Contain 1 set of chromosomes.
 Diploid: Cells used as skin, blood, or muscle
cells. Contain 2 sets of chromosomes
4.2.2 Homologous Chromosomes

Definition- 2 chromosomes, one from
each parent, that look the same
 Same size
 Same banding pattern in a karyotype
 Carry the same genes but not necessarily
allelles
 Ex. 2 chromosomes for eye color that look
the same, but one may be brown and the
other may be blue
4.2.2 (cont.)
 Chromosomes will pair up and split during
meiosis
Activity
Each person will receive a balloon and a
slip of paper with a question on it
 Take a sharpie and write your question
on your balloon
 When we begin, pass the balloons
around and choose a person to answer
a question
 If you answer correctly you may pop
your balloon. If not we will continue to
pass it.

Works Cited

Free Homework Help Videos from
Brightstorm - Math, Science, Test Prep Brightstorm. Web. 10 Feb. 2012.
<http://www.brightstorm.com/>.