INQUIRY SCIENCE
THS
CH 7: Chromosomes, Genes, & Karyotypes
Name:
Per:
p351
1. Humans have ____ chromosomes ( ____ pairs).
2. Not every species! How many chromosomes in the cells of…
…an ant? ____ …a dog?____
…a cat?____ …a fern?____
3. Considering the 23 pairs of human chromosomes, the first 22 pairs are
called______________________ while pair #23 are the ______chromosomes.
Why are they (the 23rd pair) called this?
4. An individual is FEMALE if
5. An individual is MALE if
the sex chromosomes are
the sex chromosomes are
___&___
___&___
6. Got it? Let’s see! A KAROTYPE is a “map” of an organism’s complete set of
chromosomes, matching pairs, lined up from biggest-to-smallest (and numbered).
Turn to p366 to see a human karyotype. Locate the sex chromosomes (where the
23rd pair should be!).
This is the karyotype of a human____________because…
(gender)
7. Take out the karyotype provided by the teacher. This karyotype is more advanced
than the one on p366 as some of the colored bands (“genes”) have been “mapped”
by geneticists (they have discovered what that gene does for us…or in some cases
what its malfunction causes). Look at chromosome #1. Count the genes that
have been mapped; ____ This is a 1997 map.
According to p352 how many genes are actually on chromosome #1? about_____
Using the biological symbols for gender;
karyotype of a man or a woman?
♂ = male, ♀
= female, is this the
8. People with diabetes do not produce enough of a hormone called INSULIN.
Search the karyotype for the chromosome
that makes insulin. Which chromosome # is it? ____
9. There is a gene on this chromosome that, when activated, will prevent all skin
color genes from working.
This genetic DISORDER is called___________ISM. What do you call people
with this disorder (zero pigmentation in skin, hair, or eyes)?
10. People that have a mutation in another gene on
this (same) chromosome have a fatal blood
disorder (misshapen blood cells) called ____________ ______ ____________
11. For THOUSANDS of years we have seen people with these “disorders” (it is
incorrect to call them genetic “diseases” because a disease is contagious, you get
it from pathogens) but only in the last decade or so have we figured out exactly
what causes them…exactly which gene on which chromosome!! Consider how
fast this knowledge has grown…count the number of genes that were mapped on
chromosome number eleven back in 1997. What did you get? 7? 8? Now turn
the karyotype over and look at the map of chromosome eleven from only FIVE
years later (in 2002). What’s the difference?
12. Using the 1997 map, locate/record the chromosomes that have the gene/disorder
indicated below (if it is on the 23rd write which sex chromosome, X or Y it is on);
albinism 11 .
red hair____
breast cancer____
Rh blood____
Tourette’s____
Boy in the Bubble____
brown hair____
dwarfism____
sex-determining factor____
Lorenzo’s Oil____
*an IQ gene____
grn/blue eyes____
taste receptor____
male baldness____
color blindness____
smell receptor____
*a gene controlling height____
blonde hair____
ABO blood type____
*a gene for skin color____
[
]____
13. Look on the poster on the wall and pick a genetic disorder (that NO ONE ELSE in
class picked and fill in the last blanks on question #11.
14. Notice something about the genes marked with (*)? Some traits are determined
by ONE gene (they are turned on/off like a light switch like Rh factor), others are
controlled by a few genes (like hair/eye color) while others (like these * ) are
determined by MANY genes. Geneticists call these traits MONOGENIC,
OLIGOGENIC, and POLYGENIC, respectively. Think about human phenotypes
for these (*) traits. What “phenotypic evidence” supports the claim that these (*)
are indeed polygenic?
15. Read the top of p353. Imagine you have a sibling that complains, “It’s no fair!
You got more of dad’s genes than me! You have his dark hair, brown eyes and
you’re tall like him.” Use your growing knowledge of genetics to explain to your
imaginary sibling how/why they are wrong.
16. Turn to p333. The information in this assignment is supporting which TWO
Major Concepts? Copy them below;
 .
 .