1. Cell Differentiation & Gene Expression

2. Test Yourself Q 1: Do you think living things have common genes?
Q2: Do you think humans have the same sets of genes?
Q3: Do you think different cells from the same organism have the same genes?
Q4: Do you think different cells from the same organism have different jobs/functions?

3. % of DNA Shared
The genetic information encoded in living things is similar.
Genes coding for:
Growth & development
Reproduction
Metabolism
Basic cell functions
Living things will retain parts of its original genome
key component of evolution

4. Write the name of the organism in the percentage circle to show shared DNA with humans
Try This!
chimp
mouse
98%
Baker’s yeast
cow
dog
Wine grape
Zebra-fish
platypus
chicken
roundworm
Fruit fly
honeybee

5. Cell differentiation
Cell differentiation: differentiation is the process by which a less specialized cell becomes a more specialized cell type.
Stem cells can differentiate to become all the different cell types through gene expression
Certain genes can be turned ON or OFF at different times
Example: early embryonic stem cells differentiate into liver cells or blood cells depending on the specific genes that are expressed

6. Cell differentiation is due to gene expression
Gene expression is the activation of a gene that results in a specific protein
specific proteins can dictate a specific cellular function
pancreatic cells produce the protein insulin that help in digestion whereas red blood cells have the protein hemoglobin that help in transporting O2 and CO2
Genes can be turned OFF and ON when specific proteins are needed
All somatic or body cells in an organism have the same genome- ALL 20,000 genes, but can selectively express the genes needed for it’s specific “job”

7. Scientists try and “alter” gene expression steps to cure diseases!
Gene expression is regulated throughout a cells life in order to control it’s functions
For example, you would not want the cells in your eyes to start producing the digestive enzymes that are produced by your cells in your digestive tract
Gene expression is regulated at different points “during” and “after” transcription and translation
Scientists try and “alter” gene expression steps to cure diseases!

8. Gene Regulation
Activators increase binding of RNA polymerase to the promoter gene and increases the rate of transcription
Repressors bind at or near the promoter and interfere with activity of RNA polymerase to stop transcription

9. Today’s Activity
We will be examining a variety of human cells and exploring the role of proteins in cellular functions
We will learn how the type and the amount of proteins produced by a cell are regulated

10. The Types of Cells
Beta cells are located in your pancreas and produce a hormone called insulin. Insulin regulates cellular uptake and metabolism of sugars and fats
Red blood cells produce hemoglobin. Hemoglobin is a protein which transports oxygen to every other cell in the body
Intestinal lining cells produce enzymes that contribute to steps in digestion
Smooth muscle cells are located in your digestive system and contract or relax in waves in order to help move food through the digestive tract

11. Chromosomes and Genes Expressed
We will be using chromosome 2 & 11 from the human genome
Each gene shown in the tables represent a segment of DNA on chromosome 2 and chromosome 11
- inactive gene
+ active gene
There are groups of genes which are
active in every cell
active in 1 type of cell
not active in any

12. Test Yourself Q 1: Do you think living things have common genes?
Q2: Do you think humans have the same sets of genes?
Q3: Do you think different cells from the same organism have the same genes?
Q4: Do you think different cells from the same organism have different jobs/functions?

13. State test question

14. State test question