GENETICS

HO

W T

HA

T I

NF O

RM

AT

I ON

IN

SI D

E C

ON

TR

OL S

Y OU

BASICS

Cellular level• EVERY cell in your body (with a few exceptions) has the SAME EXACT

genetic code• Code held inside the nucleus• Code is in the form of 4 different chemicals strung together in

different orders

The letters• A, T, C, G• A always goes across from T• C always goes across from G

NEXT STEP

• 4 chemicals that make you who you are

• Chemical messages• Your body communicates by making different protein messages to send

around to tell your body what to do and when

• The order of the A, T, C, and G chemicals in your genetic code tells your cell how to make a message (what building block to put in next), which then tells your body what signal will be sent

• Each cell holds approximately 10,000-20,000 codes to make different signals

• Each set of instructions is called a GENE

MAKING THE MESSAGE

Two major steps

1. Read the genetic code, transfer to something that can leave the nucleus

2. Bring signal to ribosome where protein will be built

Step 1 = transcription (changing the code over)

Step 2= translation (making transcript into message that body can understand)

TRANSCRIPTION

• DNA is opened

• Sequence of A, T, C, and G for the gene being read is copied by RNA• In RNA, A pairs with U (T does not exist in RNA), other than that,

pairing is the same

• RNA leaves nucleus to go to ribosome

TRANSLATION

• RNA goes to ribosome

• Ribosome reads RNA in 3-letter sequences• Each 3-letter sequence tells the ribosome to add a specific amino

acid to the chain to make a protein

• At end, a code tells the ribosome to stop building and release the protein

OOPS!

Mistakes in the genetic code…• If there is a mistake in the code in your DNA

• Code brought to ribosome is incorrect

• Ribosome then told to make the wrong protein

• Called a MUTATION• Sometimes can have little or no effect on the protein• Sometimes can make the protein unable to do its job

QUESTION

What are some things that can lead to mutations?

Give an example of a mutation that would only effect a specific part of the body and give an example of one that could effect your entire body.

YOUR B

ODY’S F

UNCTIONS

A P

RE

VI E

W F

OR

TH

E R

ES

T O

F TH

E Y

EA

R

5 MAJOR FUNCTIONS TO BE STUDIED

• Respiration

• Communication

• Homeostasis

• Movement

• Reproduction

RESPIRATION

*Taking in oxygen and removing carbon dioxide

• Must then circulate the oxygen to the muscles and places it is needed

• Pick up carbon dioxide and remove it from the body• Where does carbon dioxide come from and why?

COMMUNICATION

• Brain must be able to tell rest of body what to do

• Through nervous signals and hormone signals

• What are some ways these pathways can be cut off or hindered?

HOMEOSTASIS

• Body must stay at a constant internal environment• Temperature• pH

• What allows this to happen?

• What are some ways this can be disrupted

MOVEMENT

• Both internal and external• Must be able to move materials around inside of body

• Must be able to respond to environment and move externally

REPRODUCTION

Evolutionarily, this is all that matters!

• Passing traits on to the next generation is the key to life• How are traits passed on?• How are these traits selected?• What systems must work together to allow a new individual to be

born?