Genes

Key Vocabulary – Define these terms using your notes page 16.

1. External fertilization 6. Genotype2. Internal fertilization 7. Phenotype3. Gene 8. Dominant 4. Allele 9. Recessive5. Trait

So what is a gene?

Key Point #1

A gene is one section of a ______________ that contatins specific ____genetic________

information.

Do you remember chromosomes?!

this is a chromosome

this is a __________

this is a __________

gene

So what do genes do?Key Point# 2:

Genes code for (give us) a specific _______trait_______.

A trait is a characteristic or property of an organism.

What traits might Jay-Z and Beyonce’s Baby have?

How tall?

Hair color?

Color skin?

Ears?

Eyes?

Smile?

• These are all examples of _____________ traits.• Remember, the word “inherit” comes

from the word ____________________, which means “information is passed down from parent to offspring.”• What can we say about the relationship

between genes and inherited traits?• Genes DETERMINE our traits!

An example of an inherited trait is the ability to roll your tongue.

A ________ found in humans controls whether or not you can roll your tongue like the baby below.

Can you roll your tongue?

What would happen if…

Your mom can roll her tongue, and she passed that gene to you.

Your dad can not roll his tongue, and he passed that gene to you.

Will you be able to or not? You have two different forms of the same gene.

KP #3

A gene can have many different ________.

When these different forms match up on a pair of___________________, they

interact and code for a trait.

Where are gene pairs found on a chromosome?

this is a gene

this is a gene

Where is this gene’s pair?Circle it!

Two forms of a

______

Why is it important to have gene pairs located on the same place on each side of a chromosome?

Genes __________up.

Look at the stripes. They match up.

This chromosomecame from

___________

This chromosome came from

_________

Gene that controls hair

Widow’s peak (triangle-shaped hair line)

No widow’s peak (straight hair line)

Same _________(hairline) Different ______ (widow’s peak or no widow’s peak)

Gene that controls: texture of Hair

Form: A Form: a

Different forms of the same ___________

KP #4

When genes pairs match up on homologous ____________________, they code for a trait.

Practice!

• Complete the chromosome worksheet with a partner. •When you are done with that,

you are to work independently on your independent practice worksheet.