Here’s What they (OGT) has asked Here’s What they (OGT) has asked in the last 4 years………in the last 4 years………

Cell TheoryCell Theory

1. All organisms are 1. All organisms are composed of one or more composed of one or more cellscells

2. The cell is the basic unit of 2. The cell is the basic unit of organization of organismsorganization of organisms

3.All cells come from 3.All cells come from preexisting cellspreexisting cells

ProkaryoteProkaryote

1. Prokaryotes: No membrane 1. Prokaryotes: No membrane bound organelles (especially bound organelles (especially nucleus)nucleus)a. Bacteria (Kingdom Monera)a. Bacteria (Kingdom Monera)b. DNA is just “floating” around b. DNA is just “floating” around

along with ribosomesalong with ribosomesc. Mostly unicellular organismsc. Mostly unicellular organisms

EukaryoteEukaryote

1. Eukaryotic: cells containing 1. Eukaryotic: cells containing membrane-bound organellesmembrane-bound organellesa. mostly multicellulara. mostly multicellularb. some unicellular (algae, yeast)b. some unicellular (algae, yeast)C. have organelles: structures C. have organelles: structures

with special functions in the cellwith special functions in the cellD. Nucleus: largest in animal cellsD. Nucleus: largest in animal cells

Has Nucleus No Nuclear

Membrane

Ribosomes

and DNA

Cell StructureCell Structure

Cell StructuresCell Structures

1. Cell wall: rigid layer of 1. Cell wall: rigid layer of nonliving material that nonliving material that surrounds the cells of plantssurrounds the cells of plantsMade of celluloseMade of celluloseProtects and supports the cellsProtects and supports the cells

2. Cell membrane: Boundary 2. Cell membrane: Boundary that protects the cell from that protects the cell from the environment & controls the environment & controls what comes in and outwhat comes in and outAll cells haveAll cells haveLike a screen doorLike a screen door

3. Nucleus: control center for the 3. Nucleus: control center for the cellcell

4. Ribosomes: grain like 4. Ribosomes: grain like bodies on the ER & in the bodies on the ER & in the

cytoplasmcytoplasm

5.Endoplasmic Reticulum: (called ER) 5.Endoplasmic Reticulum: (called ER) carry proteins and materials within the carry proteins and materials within the

cellcell

6. Golgi Body: receives and 6. Golgi Body: receives and packages proteins from ER and packages proteins from ER and distributes around cell and body distributes around cell and body

(mailroom)(mailroom)

7. Cytoplasm: clear gelatinous 7. Cytoplasm: clear gelatinous fluid inside a cellfluid inside a cell

8. Vacuoles: storage area of the cell8. Vacuoles: storage area of the cellPlant has one large vacuolePlant has one large vacuole

Stores food, waste, & enzymesStores food, waste, & enzymes

9. Mitochondria = powerhouse of the cell; 9. Mitochondria = powerhouse of the cell; where cell energy comes from.where cell energy comes from.

10. Chloroplasts: ONLY IN PLANTS 10. Chloroplasts: ONLY IN PLANTS captures sunlight and produces captures sunlight and produces

food for the cellfood for the cell

11. Flagella = used for movement11. Flagella = used for movement

12. Cilia = used for movement; tiny 12. Cilia = used for movement; tiny hair-like structures; found on cells hair-like structures; found on cells

that need to move mucusthat need to move mucus

D. Absence of a nuclear membraneD. Absence of a nuclear membrane

B. Viruses require a host cell to B. Viruses require a host cell to reproduce.reproduce.

C. flagellumC. flagellum

B. flagellaB. flagella

Questions they (OGT) has asked Questions they (OGT) has asked the last 4 years.the last 4 years.

D. Place the rabbit in a cage with a D. Place the rabbit in a cage with a heated floor.heated floor.

EvolutionEvolution

Charles Darwin (1809-1882)Charles Darwin (1809-1882)

1.1. Natural SelectionNatural Selectiona.a. ““Only the strongest survive”Only the strongest survive”

2.2. Darwin hypothesized that when animals Darwin hypothesized that when animals had traits that helped them live, they had traits that helped them live, they would pass them on to their offspring.would pass them on to their offspring.

3.3. Animals who did not possess these traits Animals who did not possess these traits died.died.

Darwin’s ExampleDarwin’s Example

1.1. Darwin noted the different beak Darwin noted the different beak structures of finches depended on the structures of finches depended on the island they came from.island they came from.

2.2. Finches who lived on islands plentiful in Finches who lived on islands plentiful in nuts and berries had different beaks than nuts and berries had different beaks than finches who lived on islands plentiful in finches who lived on islands plentiful in insects.insects.

Even though all these birds are finches they developed different beaks depending on the

plentiful food source of specific islands.

Examples of Natural SelectionExamples of Natural Selection

1.1. Galapagos IguanasGalapagos Iguanasa.a. Some iguanas have Some iguanas have

evolved to eat algae.evolved to eat algae.b.b. Some iguanas have Some iguanas have

developed large claws to developed large claws to help them cling to rock.help them cling to rock.

c.c. These iguanas evolved These iguanas evolved from other iguanas from other iguanas because they need those because they need those two traits to survive.two traits to survive.

d.d. The algae eating, long The algae eating, long clawed iguanas passed clawed iguanas passed these trait on to their these trait on to their young.young.

e.e. Iguanas not having that Iguanas not having that trait.trait.

Everyday green iguana

Galapagos marine iguana

Other adaptationsOther adaptations

1.1. CamaflougeCamaflougea. Enables species to a. Enables species to

blend in with their blend in with their surroundings.surroundings.

Can you find the snake’s head?

2. Mimicry – enables a 2. Mimicry – enables a species to look like species to look like other speciesother species

What part of the plant is this?It’s not part of the plant at all, it’s an insect.

Darwin HypotheticalDarwin Hypothetical

1.1. Let’s say there was a new “killer” virus that affected Let’s say there was a new “killer” virus that affected dogs.dogs.

2.2. This flu bug only affected dogs with long hair. So, if a This flu bug only affected dogs with long hair. So, if a dog had long hair (more than ¾ inch long) it would get dog had long hair (more than ¾ inch long) it would get the virus and die.the virus and die.

3.3. In 20 years, will all dogs have long or short hair? In 20 years, will all dogs have long or short hair? WHY?WHY?

All dogs would have short hair because all the long All dogs would have short hair because all the long hair dogs have died from the virus. There would only hair dogs have died from the virus. There would only be short haired dogs mating with short hair dogs. be short haired dogs mating with short hair dogs.

You could say all dogs with short hair were “naturally You could say all dogs with short hair were “naturally selected” to live. The dog species has evolved from selected” to live. The dog species has evolved from having both short and long hair to having only short having both short and long hair to having only short hair.hair.

1.1. Populations evolve not individuals.Populations evolve not individuals.

B. B.

C. Had a higher survival rate than C. Had a higher survival rate than light moths in the same arealight moths in the same area

One last thing the OGT might get One last thing the OGT might get you on……you on……

Jean Baptiste Lamarck (1744-1821)Jean Baptiste Lamarck (1744-1821)Came before DarwinCame before DarwinHad some of the same ideas as Darwin Had some of the same ideas as Darwin No one ever believed him.No one ever believed him.Died in obscurity and poverty.Died in obscurity and poverty.