1. Genetics Grade 7
Please note: Punnet squares have been removed from 7th grade and will be taught in Biology.
7th grade will lay the foundation for 8th/BIO by providing a strong understanding of genes, chromosomes and DNA; heredity; sexual vs. sexual reproduction; natural selection and selective breeding.
7th grade TEKS are:
(7.11C) Identify some changes in genetic traits that can have occurred over several generations through natural selection and selective breeding such as the Galapagos Medium Ground Finch (Geospiza fortis) or domestic animals.
(7.14A) Define heredity as the passage of genetic instructions from one generation to the next generation.
(7.14B) Compare the results of uniform or diverse offspring from sexual reproduction or asexual reproduction.
(7.14C) Recognize that inherited traits of individuals are governed in the genetic material found in the genes within chromosomes in the nucleus.

2. Heredity: The process in which characteristics or traits pass from parents to offspring. Think, Pair, Share some characteristics that you have in common with either parent 2

3. Traits
Genetics – study of how traits are passed from parent to offspring

4. Genes are Found in the Nucleus of Cells
Traits are determined by the genes on the chromosomes. A gene is a segment of DNA that determines a trait.
Help students make the connection between traits (they have just identified in the “Tracking Down Traits” activity) and genes- the genetic material responsible for traits.
Genes are Found in the Nucleus of Cells

5. What Genes Do in Your Body
Each cell in the human body contains about 25,000 to 35,000 genes,
that carry information to help determine your traits.
Traits are characteristics you inherit from your parents;
This means your parents pass some of their characteristics on to you through genes
TPS: what does the statement
“ You inherit traits from your parents” mean?
This statement means that traits ( like eye color, height, etc.) come from your parents through genetic material called genes.

6. Genes carry information that helps make you who you are
Genes are made of DNA
A gene is a section of DNA that
controls a trait ( ex. tall /short) that an
organism inherits
Genes – genetic material- are made from DNA, that is tightly wound into structures called chromosomes.
TPS: if genes are sections of DNA, where are genes located in the cell?

7. What do you know about DNA?
Where have you
heard the term?
What was the context
or situation?
DNA
Write this in your notebook and be ready to share with your class as your teacher records on the board.
Lead the class to create a circle map, listing all of the things they know about DNA and where they learned that information. ( Example: DNA testing- heard about on CSI)

8. What is DNA?
The genetic material that carries information about an organism passed from parent to offspring
A complete set of instructions necessary to make and maintain the human body.
A Blueprint of the human body
Don’t teach base pairs, or sugar-phosphate backbone- BIOLOGY will cover that.
Do help students understand that DNA is like a blueprint for the human body and that every cell contains all of the DNA to “make” a human body.

9. Chromosomes
DNA is too long to fit into a nucleus, it must be tightly wound-up to fit inside the cell.
Chromosomes are DNA wrapped around proteins to form an X-shaped structure.

10. Where is DNA? Found in Cells… inside the Nucleus , the Control Center.
DNA is wound tightly into structures called Chromosomes so it can fit into a tiny cell…
so, Chromosomes are made of DNA
Short sections of DNA in the chromosomes are called Genes

11. Each human Cell have 23 pairs of Chromosomes
Mother
Father

12. How important are chromosomes?
Humans need all 46 chromosomes for normal development and function.
Humans that are missing even one of the 46 chromosomes do not survive.
Humans with more than two copies of a chromosome will not develop properly.

13. Vocabulary
Natural occurrence is Natural Selection
Natural selection is the process by which certain heritable traits—those that make it more likely for an organism to survive and successfully reproduce —become more common in a population over successive generations.
Natural selection should be covered in all classes – Pre-AP and academic.

14. Vocabulary Selective breeding:
The method of breeding certain organisms together that have desirable traits.
The process of manipulating the phenotype of the offspring.

15. Example of Selective Breeding
Hardy – can thrive in hot climates, the beef is not as good
Tender, tasty beef
Does not thrive in hot climates
Heat resistant cattle with tender beef

16. Selective Breeding - Ancestry
American Bulldog
Bull Mastiff
American Pit Bull Terrier
Staffordshire Bull Terrier