BIOLOGYUnit 2 Notes:

Plants, Animals & The Endosymbiotic Theory

(1) Plant vs Animal Cells

• Both plants and animals are made of cells.

• Because they complete different life processes + live in different environments, they require different things.

• Plants and Animals have unique, individual structures, to help them stay living and healthy.– These “structures” are called ORGANELLES.

(2) Only Plant Cells Have…

• Enlarged Vacuole:– Stores extra water for photosynthesis.– Helps increase rigidity of plant structure.

• Chloroplasts:– Converts sunlight + CO2 + water into sugars and

O2.

• Cell Wall:– Extra barrier around the whole cell.– Helps increase rigidity of plant structure.

(3) Only Animal Cells Have…

• Peroxisomes:– Used to break down Hydrogen Peroxide using

catalase.– Hydrogen Peroxide is a by-product of lipid

metabolism in animals.

(4) Both Plants & Animals Have…

• Cell Membrane

• Nucleus

• Endoplasmic Reticulum

• Golgi Body

• Lysosomes

• Ribosomes

(5) The Endosymbiotic Theory

• States:Modern eukaryotic cells evolved from free-living prokaryotic cells living symbiotically with larger unicellular organisms.

• Evidence:Mitochondria & Chloroplasts have…– DNA– Cell Membranes– Ability to Reproduce– Ability to Produce Proteins