Topic: Genetics:

How Genes are passed on?

 

 

Part One: Teacher Notes

 

Sate and National Standards:

Missouri Department of Elementary and Secondary Education:

Strand 3: Characteristics and Interactions of Living Organism

3. There is a genetic basis for the transfer of biological characteristics from one generation to the next through reproductive processes

E. The pattern of inheritance for many traits can be predicted by using the principles of Mendelian genetics

a. Explain how genotypes (heterozygous and homozygous) contribute to phenotypic variation within a species

b. Predict the probability of the occurrence of specific traits.

 

Concept:

The concept of this lesson is genes and how they are passed. This will be an easy concept to be comprehended by the students because it’s something they can relate to and can see in their families.

 

Exploration:

The activity I have chosen for the exploration part is a great activity that will force the students to search their prior knowledge and see what they already know about genes. The activity will be very simple. The students will work on their own on this part of the class activities.

 

Term Introduction:

This is one of my favorite lessons in biology because it can be easily related to the students. The students tend to understand and relate to this concept very well. The activities chosen for this lesson are very simple activities. This lesson includes an activity where the students are to work independently and will be forced to search for their prior knowledge and what they already know. The first application activity will be done in groups of two and the last activity; the second application activity will be done in groups of four. These activities tie in the concepts learned in class with their real life.

 

Term Introduction Notes:

We all know that children tend to resemble their parents in appearance. Parents and children generally have similar eye color, hair texture, height and other characteristics because children inherit genes that control specific characteristics from their parents.

Where are genes found in our bodies?

Researchers have shown that genes are parts of DNA molecules, and DNA molecules are packaged in chromosomes in the nucleus of each cell in our body.

How does a baby inherit genes from his or her mother and father?

When we talk about genes being inherited from one generation to the next, we are really talking about how the gene-carrying chromosomes behave during meiosis and fertilization. For example, the behavior of the mother's and father's chromosomes during meiosis and fertilization explains why each cell in a baby's body has two copies of each gene, one copy from his or her mother and one copy from his or her father.

The genotype refers to the genetic makeup of an individual.

The phenotype refers to the observable physical and physiological characteristics of an individual.

A gene might have different forms, called 'alleles,' that controlled the phenotype of the trait or character that it produced. Sometimes an allele could express it's phenotype over another allele for the trait that could otherwise produce a different phenotype. When two different alleles for a trait were together in an individual (a heterozygote) the allele who's phenotype was expressed was called "dominant" and the unexpressed allele was "recessive."

Many traits in humans are controlled by genes. Some of these traits are common features like eye color, straight or curly hair, baldness, attached vs. free ear lobes, the ability to taste certain substances, and even whether you have dry or sticky earwax! Other genes may actually cause disease. Sickle cell anemia, muscular dystrophy, cystic fibrosis are each caused by a specific allele of a human gene, and can therefore be inherited from one generation to the next.

 

Application 1:

The activity I have chosen for the application part is a great activity, which will be done in groups of two. This activity demonstrates the way genes behave by using a two sided coin. It is an easy activity that can be done in any classroom. I like this activity because it doesn’t require any materials and it does a great job of involving the students in the activity.

In this activity, tails will represent the recessive allele that controls pigment production (a), and heads represents the dominant allele (A). Each result of tossing the coin will represent the allele present in an egg or sperm produced by a parent who is heterozygous (Aa). In order to simulate the types of offspring produced by these parents, the students will need to find another person with whom to “mate”. Each person then tosses their coin to make a pair of genes. Each pair of genes represents the genotype of an individual offspring. Then, according to their results, they will fill out the table given and answer the questions.

 

Application 2:

The activity I have picked for this activity can get a little complicated. Therefore, I have chosen groups for the students to work in. The students will be put in groups of four and will be working together on this activity. In this activity a pedigree is given with some information and they have to fill in the blank genotypes.

 

Material List:

This lesson will not require any materials. Most of the activities in this lesson will be group activities and responding to their results. They will need a coin per group for the application 1 activity.

 

History of Concepts:

In 1865-1910, Mendel discovered that the gene was a "particle" that could not be divided. Mendel figured out that each parent contributes one of each kind a gene to an offspring. In each mature individual these were sorted and redistributed to gametes.

In 1903, Morgan discovered that genes are located on chromosomes and that genes occupy certain "loci" on the chromosomes and are sometimes were so closely linked together that they tend to "go together" into a common gamete.

 

Related Websites:

Miller, levine. Biology. Pearson Education, Inc., New Jersey:2002.

http://www.sbs.utexas.edu/genetics/1oldgenehistory.htm

http://ology.amnh.org/genetics/

http://www.stats.gla.ac.uk/undergraduate/Projects/genes.htm

http://www.ncbi.nlm.nih.gov/disease/

 

References:

http://216.83.169.90/kid/talk/qa/what_is_gene.html

http://www.sbs.utexas.edu/genetics/1oldgenehistory.htm

http://serendip.brynmawr.edu/sci_edu/waldron/genetics.html

Miller, levine. Biology. Pearson Education, Inc., New Jersey:2002.

 

 

 

Part Two: Students Pages

 

Exploration:

Answer the following questions:

What are genes?

 

 

 

Where are genes found in our bodies?

 

 

 

How does a baby inherit genes from his or her mother and father?

 

 

 

Given the Punnett square below, answer the following questions as a group: