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BIOL 100L

Laboratory Module 5

Cell Cycle, Mitosis and Meiosis

Name Date

Part 1 – Introduction to DNA, Chromosomes and Cell Division:

Objective – What do you think is the objective of Part 1 of this laboratory module? Write the objective in bullet form bellow. (1 points)

· Identify how DNA, genes, alleles, and chromosomes relate to inherited traits and cell division

Did you complete the On Line Quiz for Part 1 of this Lab Module? __X__ Yes or _____ No

The Quiz is worth 10 points of the Lab and it will be graded directly in your Gradebook in Blackboard.

Part 2 – Karyotyping:

Objective – What do you think is the objective of Part 2 of this laboratory module? Write the objective in bullet form bellow. (1 points)

· Explain how a karyotype organizes chromosomes and can identify changes in chromosome number

Paste the Screen shot of your Karyotype here. You can post a scan or Phone pic of the Old School Karyotype if you had to do it manually. (5 points)

Part 3 – Cell Cycle and Mitosis:

Objective – What do you think are the objectives of Part 3 of this laboratory module? Write the objective in bullet form bellow. (2 points)

· Objective 1 –

· Objective 2 -

Did you complete the Lab Module 5 Part 3 Quiz? _X____ Yes or _____No. The Quiz is worth 5 points of the Lab and it will be graded directly in your Gradebook in Blackboard.

Onion Root Tip Cell Activity (10 points) - After watching the videos, follow the instructions on the Onion Root tip cell experience and count up the cells found in each phase and use those numbers to predict how much time a dividing cell spends in each phase. You can base your calculation on a total cell cycle of 24 hours.

First Calculate what percentage of the cells were in each phase. For example if you counted 11 cells in Prophase and there are 36 total cells that means that (11/36)x100 = 30% of the cells were in prophase. That means that the cells in this onion spend 30% of the time in prophase. So you can calculate what is 30% of 24 hrs and find out what amount of time the cells spend in this phase of the cell cycle. Now do the same for each phase using the actual numbers you recorded from the on-line experience.

Table 1. Number of cells on each phase of the cell cycle.

	Interphase	Prophase	Metaphase	Anaphase	Telophase	Total
number of cells						36%
percent of cells						100%

Part 4 - Meiosis

Objectives – What do you think is the objective of Part 4 of this laboratory module? Write the objectives in bullet form bellow. (2 points)

· Objective 1.

· Objective 2.

Did you complete the On Line Quiz for Part 4 of this Lab Module?

____ Yes or _____ No

The Quiz is worth 10 points of the Lab and it will be graded directly in your Gradebook in Blackboard.

Part 5 – Meiosis and Disease in Humans

Sometimes during Meiosis, a chromosome or a sister chromatid fail to separate during Anaphase I or Anaphase II. This problem is called NON-DISJUNCTION.

If this happens, it can result in a sperm (or egg) with 2 copies of Chromosome 21 for example. If that sperm with two copies of Chromosome 21 fertilizes an egg with that caries the expected 1 copy of Chromosome 21, the Zygote formed will have 3 copies of Chromosome 21 instead of the 2 expected copies. This is called a TRISOMY. In the example I am giving you, a Trisomy of Chromosome 21 results in a baby with Down Syndrome.

Do an internet search and Identify another condition in humans that results from a NON-DISJUNCTION. (4 points)

Name of the condition: ______________________________________________

Cause of the condition: ______________________________________________

Describe the symptoms: ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________