Genetics Activity: Bloops Lab

The Genetics of Bloops

Performance Expectation: Develop and use a model to describe why asexual reproduction results in offspring with identical genetic information and sexual reproduction results in offspring with genetic variation.

Essential Question: Why does asexual reproduction result in offspring that are identical and sexual reproduction result in offspring with variation?

Genetics Background Information:

In this activity you will be building “Bloops” based on genetic information you have gathered. “What are Bloops?” Bloops are a friendly species that are excellent for studying genetics! Bloops are reproduced through sexual reproduction (two parents) so this assignment only focuses on variation of traits and not identical traits produced from asexual reproduction (one parent).

So what is genetics? Genetics is the scientific study of how physical and behavioral traits are passed from parents to their offspring. Gregor Mendel (1822-1884) was an Austrian-born botanist, teacher and monk. He created the principles of heredity in 1865. Heredity is how characteristics, or traits, are passed on from parents to offspring. Mendel studied pea plants which laid the groundwork for modern genetics. Between 1856 and 1863, Mendel cultivated and tested over 29,000 pea plants, focusing on just seven pairs of characteristics or traits such as plant stem height, flower color, seed color and pod texture. He created a system of inheritance by units, which we know today as genes. Inheritance introduced the idea that offspring inherit individual markers (traits) from their parents which is also known as Mendelism. Before Mendel, it was assumed that an offspring's traits were a blend of traits from their parents.

Mendel's work was supported by later scientific research and the discovery of chromosomes. Chromosomes are molecules made up of DNA. Genes are smaller segments of DNA. Mendel's work is further explained below using our understanding of inheritance today.

You inherit half of your genetic information from your biological mother and half from your biological father. Genes are passed as separate and distinct units from one generation to the next. Humans have 46 chromosomes which are sorted into 23 pairs. Each pair includes one chromosome passed from the mother and one chromosome passed from the father. Each chromosome contains one allele, or a different form (or version) of a gene (see the different colors on the chromosome pairs to the left) for each trait. For example, the mother’s chromosome can have an allele for blond hair while the father’s chromosome can have an allele for brown hair. The alleles code for the same trait – hair color. Remember genes are the instructions to make proteins and many genes can determine one or multiple traits.

Offspring can have different combinations of traits such as hair color or eye color. For example, an offspring could have blond hair and blue eyes or brown hair and brown eyes. Other mixtures of traits are also possible such as blond hair with brown eyes or brown hair with blue eyes. When alleles are passed from parent to offspring, one allele exerts greater influence over the other of the same gene and that trait will “show up” in the appearance. Mendel developed the concept of dominance from his experiments with pea plants. It was based on the uncertain belief that each plant carried two trait units (alleles), one of which dominated (covered up) the other. The allele that covers up the other allele is called the dominant allele and the allele that gets covered up is called therecessive allele.

A distinction is made between the appearance, or outward characteristic of an organism and the alleles it carries. The observable traits make up the organism's phenotype and the combination of alleles (genetic makeup) is called its genotype. An organism’s genotype is written as two letters for every gene, for example AA, Aa, and aa.

As a result of the interaction of dominant and recessive genes individuals can have a homozygous genotype (AA or aa) or a heterozygous genotype (Aa). “Homo” means the same and “hetero” means different.

If you know the genotype of the parents then it is possible to predict the likelihood of an offspring inheriting a particular phenotype. Predicting the likelihood of an offspring's phenotype involves the concept of probability, which simply means the chance that a given event will occur. Probability is usually expressed as either a fraction or a percent.

In genetics, the probability of a particular phenotype appearing in an offspring can be determined by visualizing how the genotypes of the parents might interact to generate the possible genotypes of the offspring. These interactions are called crosses. Punnett Square charts are used to show the possible genotypes for one offspring. One parent’s genotype is written across the top and the other parent’s genotype is written down the left side. You match each allele across or vertically to determine a POSSIBLE genotype for one offspring. See the example to the right → According to this example, an offspring would have a 50% chance of being born with a Gg genotype (green pod color) and a 50% chance of being born with a gg genotype (yellow pod color).

Background Questions:

1. What is the difference between asexual and sexual reproduction? 
2. What does the term genetics mean? 
3. Gregor Mendel is known as the “Father of Genetics.” His studies supported the principles of heredity. What type of organisms did he study? 
4. Gregor Mendel discovered “units” of hereditary information known today as _______________.
5. What is the relationship between DNA, genes and chromosomes? 
6. You inherit _____________ of your genetic information from your mother and ________________ from your father.
   
7. Humans have _______ chromosomes which are sorted into __________ pairs.
8. What is an allele? 
9. What is the difference between a dominant and recessive allele? 
10. Genotype or Phenotype? Blue is an example of a __________________________________ and Bb is an example of a _________________________________.
11. Genotypes can be homozygous or heterozygous. What is the difference? 
12. What is the purpose of a Punnett Square? 

Bloops Traits:

In this assignment, you will create your own Bloop based on the genetic traits (characteristics) of the Bloop’s parents.

All Bloops will have the following traits:

• Egg shaped head
• Plastic cup body (optional)
• Two antennae
• Nose
• Tail
• Eyes
• Wings

Bloops have also inherited several traits that may vary from Bloop to Bloop:

• Eye color
• Antenna color
• Tail shape
• Spotted or Striped Wings

Procedure:

Part I: Determining Your Bloop’s Genotype:

1. Without looking into the bags, pick one bead from each of the four bags marked “paternal genes.” Paternal means father.
2. Connect these four beads in the following order to make a simple bloop chromosome: eye color bead, antennae color bead, tail shape bead, wing bead. This represents a chromosome that your bloop would have inherited from its father.
3. Again, without looking into the bags, pick one bead from each of the four bags marked “maternal genes.” Maternal means mother.
4. Connect these four beads in the same order as you did previously to make another simple bloop chromosome. This represents a chromosome that your bloop would have inherited from its mother.
5. Place the two chromosomes side by side making sure that the beads for each trait line up next to each other. These lined up colors represent alleles. Refer to the data table on page 4 to determine the genotype for each of the four traits represented by the various bead color combinations. Leave the chromosomes on the table until you complete the next step.
6. Fill in the first three columns in the first data table on page 6 and the chromosome model.
7. Please return your chromosomes back to the front table when you are finished with them so they can be reused. Mrs. Gormley will take them apart and put them back in the correct bags.

Part II: Determining Your Bloop’s Phenotype & Materials

1. Based on the genotypes that you generated for each trait determine the phenotype for each trait. Fill in the phenotype information for your Bloop in the last column of the data table on page 6. You’ll need to use the data table on page 4 to know what the traits are.
2. Based on the Bloop’s phenotype, gather the appropriate materials for your Bloop and begin building your Bloop model.
   1. Eyes: Use red or green beads or markers (to draw on eyes)
   2. Nose: Use a colored push pin (your choice of color)
   3. Antennae: Use the blue or yellow toothpicks
   4. Tail: Use a pipe cleaner (If your Bloop’s tail shape is curly, wrap the pipe cleaner around a pen or your finger to produce the curly effect. If your Bloop’s tail is zig zag, bend the pipe cleaner back and forth to create a zig zag shape. )
   5. Wings: Cut wings (any shape and size) out of the cardstock. Use a sharpie marker or pen to draw spots or stripes on the wings. Next, push them into the side or back of your bloop. (You may have to slice narrow grooves on each side of the body with scissors so the wings can be attached.)
3. If you would like your Bloop to have a “body” you can use the hot glue gun to glue the Bloop to an upside down plastic cup. You may decorate and name your Bloop with markers if you would like to. You can take your Bloop home with you on Tuesday!

Data Table:

Chromosome Model:

Label the 4 genotypes on the model of the chromosome pair below. Please refer to page 1 for an example.

Bloop Model:

After you build your Bloop, please draw a model of your Bloop below. Please use colored pencils and be sure to draw the correct phenotype.

EXTRA CREDIT! (This is optional if you want to challenge your science skills!)

Punnett Square Challenge:

Find a “mate” in class and complete the 4 Punnett squares below to determine the probability of the offspring’s genotype and phenotype for the 4 different traits.

Eye Color: Antennae Color:

Green Eyes: _____________% Blue Antennae: _____________%

Red Eyes: _______________ % Yellow Antennae: _____________%

Tail Shape: Wings:

Curly: _____________% Striped Wings: _____________%

Zig Zag: _______________ % Spotted Wings: _____________ %

GOOGLE DOC LINK:  Copy of The Genetics of Bloops Engagement Lab - Google Docs

REFERENCE: FACEBOOK -- MIDDLE SCHOOL SCIENCE TEACHERS