Links necessary for lab:
https://glencoe.mheducation.com/sites/dl/free/0078802849/383933/BL_23.html
Lab Exercise 10: Genetics
Purpose of the lab:
The purpose of these laboratory exercises is to introduce the student to the basic concepts of
Genetics: Cell cycle, Mitosis and Meiosis, and Karyotypes. These concepts will reinforce the
lecture material and will be demonstrated by doing dry labs.
Activity 1: Let us learn about DNA
First, let us make sure we understand what part of the cell we will be thinking about in today’s
lab. This is a diagram of an animal cell. Please label the organelle where the DNA would be
found and draw the DNA.
1) DNA stands for _____________________________________________________
2) DNA is a nucleic acid made up of the basic unit _________________________
3) This nucleotide is made up of _______________, _______________, and
_________________
4) The shape of the DNA model is a ______________________________
5) If you compare the shape of DNA to a helical ladder, then the side rails are made up of
alternating _______________ and ______________, and the steps are made up of four bases:
______________, ________________, _______________, and _______________
6) These bases are linked together by a ______________ bond.
7) The bases follow the complementary base pair rule where A bonds with __________, and G
bonds with _____________.
Draw the structure of DNA here:
2
2
Activity 2: Let’s learn about the cell cycle and the process of Mitosis
Let us also make sure we understand the phases of the cell’s life cycle:
Go to the “Mitosis Simulation” available in Canvas. Follow the on-screen instructions to work
through the simulation. Use the images from the simulation to help you with the following:
Phases of Mitosis: Please label the phases below:
http://anatomycorner.com/cell/cell_notes.html
3
3
Label the following: Mitosis
Activity 3: Meiosis activity
https://www.google.com/search?q=cell+cycle&espv=2&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj5-
pPKqNfSAhWIqlQKHYSXD_AQ_AUIBigB&biw=1366&bih=613#tbm=isch&q=meiosis&*&imgrc=JYB5DtvLNIeywM:
4
4
Practice: Name the different stages of meiosis and arrange the following in order:
Activity 5: Karyotype Reading
A karyotype is simply a picture of a person’s chromosomes. In order to get this picture, the
chromosomes are isolated, stained, and examined under the microscope. Most often, this is done
using the chromosomes in the white blood cells. A picture of the chromosomes is taken through
the microscope. Then, the picture of the chromosomes is cut up and rearranged by the
chromosome’s size. The chromosomes are lined up from largest to smallest. A trained
cytogeneticist can look for missing or extra pieces of chromosome.
There are 22 numbered pairs of chromosomes called autosomes. The 23rd (last) pair of
chromosomes are the sex chromosomes. They determine an individual’s gender. Females have
two X chromosomes, and males have an X and a Y chromosome.
Each chromosome has been assigned a number based on its size. The largest chromosome is
chromosome 1, and 21 is the smallest pair.
Read the following Karyotypes
5
5
Activity 6: Non-disjunction in Meiosis
Here are the results of non-disjunction of the sex chromosomes (Allosomes):
6
6
1. XXY
2. XXX
3. XO
4. YO
Here is a common example of non-disjunction of the autosomes:
1. Down’s syndrome (Trisomy 21)
Non-disjunction can happen in one of two ways:
1. Matched pairs of chromosomes fail to separate during ________________
2. Sister chromatids are not pulled apart during ________________________
Thought question: Work together to answer this question:
Nondisjunction results in an uneven distribution of chromosomes during cell replication. If
nondisjunction occurs during meiosis I, the homologous chromosomes do not separate. If
nondisjunction happens in meiosis II, sister chromatids do not separate. If a cell has a diploid
number of six (2N = 6) before meiosis, how many chromosomes will be in each of the four
daughter cells if one pair of chromosomes experiences nondisjunction during meiosis I?
A. Two cells will have 6 chromosomes, two cells will have none.
B. Two cells will have 4 chromosomes, two cells will have 2 chromosomes.
C. Two cells will have 5 chromosomes, two cells will have 1 chromosome.
D. All four cells will have 3 chromosomes.
Nondisjunction in a Human Female
Abnormal Gamete
(egg)
Normal Gamete
(sperm)
Zygote’s
Genotype
Expected
Sex
Name of
Syndrome
X
X
Y
Y
Nondisjunction in a Human Male
Normal Gamete
(egg)
Abnormal Gamete
(sperm)
Zygote’s
Genotype
Expected
Sex
Name of
Syndrome
Papers are written from scratch We have molded our writers to develop content for all assignments from scratch. This way, we promote originality and reduce cases of plagiarism that might affect your grades and hinder you from realizing your academic goals. We encourage our clients to indicate the deliverables that should be featured in the final paper. Our online help services allow one to make a clarification and even interact with the writer directly to help them understand the needs of the assignment. Many of our writers are professional tutors who understand the approaches that should be used to fulfill the specified instructions. Every time a client places an order on our system, we link them with the most qualified writer in the subject of interest.
YUnlike other writing companies, we encourage clients to draw back their money at any stage of the writing process if they experience any uncertainties with the quality of generated content. However, you will hardly have to make this decision because of our business approach that suits your needs.
We have an advanced plagiarism-detection system that flags any work that fails to meet the required academic expectations. Our company thrives in honesty, and as such, you will be guaranteed to achieve a paper that meets your expectations.
We encourage our clients to return papers for revision seven days after the last submission for free. Depending on the proposed changes, we will work on your article to achieve the desired expectations.
We uphold confidentiality and privacy through our interactions with clients, an aspect that has enhanced our relationship with prospective customers seeking for assignment help. We do not disclose your information with third-parties
We boast of a diverse pool of ENL and ESL professionals who respond with a personal touch to the needs of every client. Our focus is to become the best platform that offers specialized services to individuals to accomplish their academic goals.
