Honors Biology Lab Manual

Unit 6: Genetics

Name: ______

Teacher: ______

Period: ______

Unit 6 Portfolio: Grading Rubric (100 points)

Total
Item(s) / 4 / 3 / 2 / 1 / Score / Weight / Points
Format/Completion / Labs/Activities, Unit Reflection, Article & Reflection, Personal Choice Item / Student has all labs/activities complete and all other components completed. / Student is missing 1 lab data, or 1 of the other 4 components / Student is missing 2 lab data, or 2 of the other 4 components / Student is missing 2 lab data, and 2 or more of the other 4 components / 2 / /8
Conventions / 1 or fewer errors in spelling, punctuation & grammar, complete sentences / 2 -3 errors in spelling, punctuation & grammar, complete sentences / 4-5 spelling, punctuation, &/or grammar errors, complete sentences / Inclusions are sloppy: cross-outs, tears, &/or creases or >4 errors in spelling punctuation &/or grammar, complete sentences / 2 / /8
Labs/Activities/Article/Reflections / Labs/Activities ** / All data/calculations/analysis questions for labs are complete & correct / 1-2 Missing/Incorrect data/calculations/Analysis questions / 3-4 Missing/Incorrect data/calculations/Analysis questions / >4 Missing/Incorrect data/calculations/Analysis questions / 6 / /24
Unit Reflection / Reflection answers all 5 guiding questions and thoroughly shows areas of increased knowledge / Reflection answers all 5 guiding questions and shows areas of increased knowledge / Reflection answers all 3-4 guiding questions and thoroughly shows areas of increased knowledge / Reflection answers less than 3 guiding questions and shows little gained knowledge / 5 / /20
Article & Reflection / Article chosen relates to unit, is summarized, &rationale includes several examples of connections / Article chosen relates to unit, is summarized, &rationale includes 1-2 examples of connections / Article chosen relates to unit, is summarized, &rationale includes only one example of a connection / Article chosen barely relates to unit (is summarized) and no or weak connections shown in rationale / 5 / /20
Personal Choice Item / Item is complete with a complete explanation of concept included. Item/explanation illustrates an accurate and thorough understanding of every key idea within the concept(s) chosen. / Item is complete with a mostly complete explanation of concept included. Item/explanation illustrates an accurate understanding of most key ideas within the concept(s) chosen. / Item is complete with some explanation of concept included. Item/explanation illustrates an accurate understanding of a few to no key ideas within the concept(s) chosen. / Item is sloppy or incomplete. No explanation of the concept/key ideas is included or item/explanation of concept/key ideas is inaccurate. / 5 / /20
Total / / 100

**Please indicate the 3-4 labs you want graded for accuracy with an asterisk (*) in the upper right hand corner of the page!

If you do not indicate which labs you wanted graded for accuracy, I will grade the first 4 labs in the manual.

Unit 6: Genetics

Vocabulary

3 | Page

Allele

Amniocentesis

Carrier

Dominant

Genetically Modified Organism (GMO)

Heterozygous

Homozygous

Karyotype

Mode of Inheritance

Pedigree

Plasmid

Punnett square

Recessive

Recombinant DNA

Restriction enzymes

Sticky ends

Transgenic organisms

Vector

3 | Page

3 | Page

Objectives

I can:

  1. Evaluate chromosome data (karyotype)
  2. Determine if the individual is male or female
  3. Determine if the individual is normal or abnormal
  4. Communicate syndrome diagnosis from data in karyotype
  5. Use mathematical data to support diagnosis
  1. Apply concepts of statistics and probability to explain the variation and distribution of expressed traits in a population.
  2. Setup and solve complete dominance Punnett squares
  3. Dimples, Fur color…
  4. Setup and solve incomplete dominance problems
  5. Knowing the heterozygous is a combination or mixture
  6. Set up and solve complete dominance problems
  7. Knowing the heterozygous has both parents characteristics present
  8. Set up and solve multiple allele problems
  9. Blood types
  10. Set up and solve sex-linked trait problems
  11. Hemophilia and color blindness
  12. Set up and solve polygenic traits
  13. Hair color and skin color
  14. Explain epigenetics and give examples of how this effects organisms
  1. Explain the role of genetic counseling for parents regarding their potential offspring
  2. Solve pedigree problems
  3. Determine genotypes of individuals in a pedigree
  4. Determine if the trait shown is dominant or recessive
  5. Determine if the trait shown is autosomal or sex-linked
  6. Explain genetic screening and why a person or family may decide to have this done
  1. Describe the various ways scientists/industry are using genetic engineering
  2. Explain the process used to create recombinant DNA
  3. Evaluate the uses of recombinant DNA
  4. Explain the benefits and harms of Genetically Modified Organisms (GMO)
  1. Explain various ways in which scientists are using gene technology to make advances in human health.

Chromosomal Mutations & Karyotyping

Purpose: to explain what a chromosomal mutation is and how a human karyotype is used to identify specific genetic disorders

Introduction

Each species has a characteristic number of chromosomes; for example, corn cells have 20 chromosomes, mouse cells have 40 chromosomes, and human cells have 46 chromosomes. In order to view the chromosomes so that they may be counted, a cell will be allowed to reproduce and colchicine is added to stop the cell division during metaphase. The resulting cells are placed in a hypotonic solution that causes the cell membranes to rupture. The chromosomes are stained and photographed. The chromosomes may then be cut out of the photograph and arranged by homologous pairs according to size, position of the centromere and the characteristic banding pattern. The resulting display is called a karyotype. See Figure I.

Figure I: Karyotyping Procedure

Part I - The Normal Human Karyotype

The normal human karyotype is composed of 46 total chromosomes. The first 22 pairs (chromosomes 1-22) are known as autosomes (code for general human traits); the 23rd pair is known as the sex chromosomes (X and Y). Females have two X chromosomes (XX) and males have one X chromosome and one Y chromosome (XY).

1. Observe the normal human karyotype chart found in FIGURE II (next page).

Figure II – Normal Human Karyotype Chart

Q1. What is the total number of chromosomes found in this cell? ______

Q2. How many autosomal chromosomal pairs are visible in the above karyotype? ______

Q3. What are the THREE chromosome characteristics used to organize the karyotype?

Q4. What is the sex of the above individual? ______

Q5. Could two individuals have the same karyotype? Explain.

Part II – Identifying Genetic Disorders

Karyotypes can be used to identify a number of chromosomal mutations. Chromosomal mutations can result in changes in the number of chromosomes in a cell or changes in the structure of a chromosome. Unlike a gene mutation which alters a single gene or larger segment of DNA on a chromosome, chromosome mutations change and impact the entire chromosome. Nondisjunction is the failure of chromosomes to separate properly during meiosis. This can result in monosomy (one chromosome instead of a pair) and trisomy (three chromosomes instead of a pair) conditions, as well as chromosomes with missing or extra segments. See Table I for some of the genetic conditions and clinical effects caused by chromosomal mutations.

Table I

Q6. What is the difference between monosomy and trisomy?

Q7. How could nondisjunction result in an individual with Down syndrome?

2. Observe the abnormal human karyotype chart found in FIGURE III.

FIGURE III – Abnormal Human Karyotype Chart

Q8. What is the sex of the individual? ______

Q9. What is the total chromosome count? ______Is this normal? ______

Q10. Using Table I, identify the condition present in this individual. ______

Part III – Internet Activity

The following site has an interactive karyotype activity. Go to the site and read the introduction, then click on the patient histories.

http://www.biology.arizona.edu/human_bio/activities/karyotyping/karyotyping.html

Start with Patient A and complete the karyotype. Answer the questions below and repeat for Patients B and C.

Q11. What notation would you use to characterize Patient A’s karyotype? ______

Q12. What diagnosis would you give Patient A? ______

Q13. What notation would you use to characterize Patient B’s karyotype? ______

Q14. What diagnosis would you give Patient B? ______

Q15. What notation would you use to characterize Patient C’s karyotype? ______

Q16. What diagnosis would you give Patient C? ______

Flower Color Genetics Lab

Objective

Apply concepts of statistics and probability to explain the variation and distribution of expressed traits in a population.

Background

A certain species of plant produces either bright red flowers or pure white flowers. In working out the inheritance of a trait with contrasting forms such as flower color, it is important to determine which symbols will be assigned to the alternative forms (alleles) of the genes for the trait (in this case, red and white). The first letter for one of the alternative forms of the trait is generally used to represent the alleles for a trait. A capital letter is usually assigned to the dominant allele, and a lowercase letter is assigned to the recessive allele. For example, if R is used to represent red, then r would represent white. Or, if W is used to represent white, then w would represent red. The pair of genes that determines a trait is called a genotype. The genotype is represented by the pair of letters that symbolizes the alleles present. When both genes in the pair are the same, the genotype is said to be homozygous. When the genes in a pair are different, the genotype is said to be heterozygous.

Purpose

In this activity, you will perform simulated crosses between red-flowered plants and white-flowered plants. Based upon the preceding paragraph, identify and state the problem that needs to be solved before the inheritance of flower color in this plant can be studied further.

To recall how the results of a cross are predicted, complete the following exercise. In cats, black coat color, B, is dominant to white coat color, b. To predict the possible coat colors of the kittens that would result from a cross between two heterozygous black cats (Bb x Bb), complete the following Punnett square.


Procedure

In order to simulate crosses between plants with red or white flowers, you will use solutions to represent flower color. The pink solutions represent plants with red flowers. The clear solutions represent plants with white flowers. Assume that plants with a particular flower color may or may not be carrying a gene for alternate flower color. When you mix the two solutions, the color of the resulting mixture represents a flower color that could be observed among the offspring of two plants if you were to actually cross plants with flowers the same colors as the solutions.

Caution: The solutions you will use in the following experiment contain chemicals that could damage your skin, eyes or clothing. Follow the suggested safety precautions. Also, be aware that contamination will have adverse effects on your data, pay attention and only mix solutions in designated containers. If you feel that contamination has occurred, let your instructor know immediately. When you have finished your experiment, all solutions may be rinsed down the sink drain.

1.  Obtain 8 small test tubes from the materials table. Label them 1-8.

2.  Obtain 1 mL of each of the solutions in the table below. Be careful not to contaminate solutions!

3.  Record the “flower” color (red or white) of each to complete the table.

Color
Solution #1
Solution #2
Solution #4
Solution #5
Solution #7

4.  Perform Cross #1: pour solution #1 and solution #2 into test tube #3; invert to mix. Record the phenotypes (colors) of the parents and resulting offspring in the boxes below.

X

Parent #1 Parent #2 F1 offspring (#3)

5.  Perform Cross #2: pour solution # 4 and solution #5 into test tube #6; invert to mix. Record the phenotypes (colors) of the parents and resulting offspring in the boxes below.

X

Parent #4 Parent #5 F1 offspring (#6)

6.  Based on the background information and the results of cross #1 and cross #2, which flower color is dominant? Which flower color is recessive? Use the Punnett squares below to determine heredity of flower color.

Cross #1

Cross #2

7.  Fill in the boxes below with the genotype of each flower based on your prediction above. If you determined red to be the dominant flower color, use R/r to represent red/white flowers. If you determined white to be the dominant flower color, use W/w to represent white/red flowers. If a genotype cannot be determined with complete certainty, write both possible genotypes.

Cross #1

X

Parent #1 Parent #2 F1 offspring (#3)

Cross #2

X

Parent #4 Parent #5 F1 offspring (#6)

8.  Test your prediction of the dominant flower color by performing Cross #3: pour solution # 6 (test tube #6) and solution #7 into test tube #8; invert to mix. Record the phenotypes (colors) of the parents and resulting offspring in the boxes below.

X

Parent #6 Parent #7 F1 offspring (#8)

9.  Fill in the boxes below with the genotype for Cross #3. If a genotype cannot be determined with complete certainty, write both possible genotypes.

Cross #2