NOTES & STATIONS: HUMAN CHROMOSOMES PERIOD: NAME: DATE:

BRAINSORM: How is human DNA similar to the DNA of other organisms? How is it different? CHROMOSOME NUMBER

• DNA’s basic __________________________________________ is the ________________ across all organisms.

• However, each species has ____________________________________________________________ as well as

___________________________________________________________________________________________.

• For example:

• In ______________________________________________________ organisms, chromosomes typically come in

______________________________ - one from ____________________ and one from ___________________.

• Homologous pair = ___________________________________________________________________________

__________________________________________________________________________________________.

HUMAN KARYOTYPE: HUMAN CHROMOSOMES:

• Humans have _______________________________________________________ chromosomes.

• There are _______ versions of each chromosome: one version from _______________________ and one from

___________________________.

• The 2 versions are called ________________________________________________________________.

• Because humans have 2 versions of each chromosome, they are called ___________________________________.

o The prefix “di-“ means _________________!

STATION 1: HOW CAN WE USE A KARYOTYPE TO DETERMINE A PERSON’S SEX? Please read the instructions at your station and the sections titled “Sex Determination” and “Figure 9” on pg 305 of your text. Then, use this information to answer the questions below.

1) Please define the following terms:

o Autosomes = ________________________________________________________________________.

§ How many pairs of autosomes do you have? ______________

o Sex chromosomes = __________________________________________________________________.

§ How many pairs of sex chromosomes do you have? _____________

§ Human females have _______ sex chromosomes. Human males have _______ sex chromosomes.

2) Please circle the sex chromosomes in each karyotype below. Then, please identify the sex as “male” or “female.” Individual A:

Sex: ______________________________________

Individual B:

Sex: ________________________________________

3) Infer: Do you think it would be more likely that a human could survive without an X chromosome or without a Y chromosome? Discuss this question first with your group and then write a short paragraph (4-5 sentences) in your own words. (Hint: Use evidence from the picture and diagram on pg 305 to support your inference.)

STATION 2: NORMAL KARYOTYPE AT EACH STAGE OF THE CELL CYCLE

Humans'Chromosomes'at'Each'Stage'of'the'Cell'Cycle:'

46'Chromosomes'in'the'human'cell'(2'versions'of'each'of'the'23)'

92'Chromosomes'a?er'replicaAon'(2'copies'of'each'of'the'46)'

DNA''REPLICATION'

CELL'DIVISION'

STATION 3: USING KARYOTYPES TO DIAGNOSE GENETIC DISORDERS For each patient below, please circle any chromosomal abnormalities and write the name of the genetic disorder they show.

Could you diagnose ANY genetic mutations using a karyotype? Why or why not? (Hint: Think about the different types of mutations we learned about this week.)

Pa#ent'A:'Pa#ent'B:'

Pa#ent'C:'Pa#ent'D:'

'''1'''''''''''''2''''''''''3'''''''''''''''''''''''''''''''''''4''''''''''5'

'''6'''''''''7'''''''''''8''''''''''9''''''''''10'''''''''11'''''''''''12'

13''''''''14''''''''15''''''''''''''''''''''16'''''''''''17'''''''18'

19''''''''20'''''''''''''''21'''''''''22'''''''''''''''''X'''''''''Y'

Pa#ent'E:'

STATION 4: DISCOVERY OF DNA

SCIENTISTS WHAT THEY DISCOVERED ABOUT THE STRUCTURE OF DNA

HOW THEY GATHERED EVIDENCE FOR THEIR CONCLUSIONS (THINK ABOUT THE STRATEGIES,

INVESTIGATIONS, ETC. THAT THEY DID)

CHARGAFF

FRANKLIN

WATSON & CRICK