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IC
Geneticist’s Name: _________________________________ Class: 8__ Date: ______________
Mrs. Bouchard – 8th Grade Science
Chromosomes
The cell’s nucleus contains _________________________________________.
Chromosomes are made up of __________________________________.
The chromosome _______________________________________________________________.
The DNA is very long and would not fit into the nucleus if they were not tightly packed.
There are many parts of chromosome that _____________________________________.
In fact, about 97% of a chromosome of a human has no genes
These parts of the chromosomes between the 2 genes are called _________________________
______________________________________________________.
Directions: Read the following text and then raise your hand to map your chromosomes to
match the description in the text. You will then present your map to the class as a group.
Eukaryotic cells are more complex than prokaryotic cells are. The chromosomes of eukaryotic
cells contain more DNA than those of prokaryotic cells do. Different kinds of eukaryotes
have different numbers of chromosomes. More-complex eukaryotes do not necessarily
have more chromosomes than simpler eukaryotes do. For example, fruit flies have 8
chromosomes, potatoes have 46 chromosomes, and humans have 46. The chromosomes
are arranged in pairs, with similar chromosomes (containing the same genes) matching
together. These pairs are called homologous chromosomes. So how many chromosome
pairs do humans have? Both chromosomes of each pair carry genes controlling the same
inherited characteristics. For example, if a gene for eye color is situated at a particular
location (locus) on a certain chromosome, then the matching chrom0some will also have a
gene specifying eye color at the equivalent locus. However, the eye color code itself might
not be the same. For each homologous chromosome pair, one chromosome came from the
female sex cell, and one came from the male sex cell. This means that the chromosomes
will contain the same genes, but the specific DNA code for each of the genes will not match
exactly because they did not come from the same source. This is an important part of
genetic diversity among any species.
Work Hard. Get Smart.
HW-69
Geneticist’s Name: _________________________________ Class: 8__ Date: ______________
Mrs. Bouchard – 8th Grade Science
Homework: Chromosomes
Directions: Answer the multiple choice question below and then explain why you chose it and
what evidence you used to get to that answer.
Which of the following best describes the number of chromosomes in a normal human liver cell?
a.
23 pairs of chromosomes
c. 46 male chromosomes, 46 female chromosomes
b.
46 different types of chromosomes
d. 23 original chromosomes, 23 duplicate
chromomes
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