Unit 3

BIO.1C.1 - Organelles and How They Work Together

Need to know

• Nucleus: stores the genetic information for making proteins.
• Ribosome: assembles proteins using that information.
• Endoplasmic reticulum: carries new proteins onward.
• Golgi apparatus: modifies and packages proteins for transport.
• Lysosome: breaks down waste and worn-out parts.
• Mitochondrion: releases energy from food.
• Chloroplast: captures light energy and is found only in autotrophs.
• Vacuole: stores water, wastes, and other materials.
• Cytoplasm: holds cell structures in place.
• Cell membrane: controls what moves in and out.
• Cell wall: supports and protects.
• Endosymbiotic theory states that mitochondria and chloroplasts began as separate cells taken inside a larger cell.

Be able to do

• Label a plant cell and match each structure to its primary function.
• Trace the protein pathway in order: ribosome → endoplasmic reticulum → Golgi apparatus → out of the cell.
• Split the protein job correctly: the nucleus stores the information and the ribosome uses it to build the protein.
• Predict which tissue has the most mitochondria from its energy demand, such as heart tissue compared with bone tissue.

BIO.1C.2 - Comparing Cell Types

Need to know

• Prokaryotic cells have no nucleus, have DNA in the cytoplasm, and have no membrane-bound organelles.
• Eukaryotic cells have a nucleus and membrane-bound organelles.
• Both prokaryotic and eukaryotic cells have a cell membrane and ribosomes.
• Plant cells are autotrophic; animal and fungal cells are heterotrophic.
• Fungal cells have a cell wall but no chloroplasts.

Be able to do

• Locate the nucleus on a eukaryotic cell model.
• Use the presence or absence of a nucleus to sort prokaryotic and eukaryotic cells.
• Use the presence or absence of chloroplasts to sort autotrophic and heterotrophic cells.
• Read a trait table for plant, animal, and fungal cells and conclude that all three share a cell membrane and organelles but differ in how they obtain energy.

Watch out for

• A cell wall does not automatically identify a plant cell. Fungi and bacteria also have cell walls.

BIO.1C.3 - Viruses vs. Cells

Need to know

• A virus has genetic material and a protein capsid.
• A bacterium has genetic material plus ribosomes, cytoplasm, a cell membrane, and a cell wall.
• Ribosomes are structures bacteria have and viruses lack. Viruses must borrow a host cell's ribosomes because ribosomes assemble proteins.
• Viruses also lack the organelles that supply energy and package materials, so they cannot carry out the work of reproduction on their own.

Be able to do

• Explain why a virus needs a host: it has no cellular machinery of its own and must use the host cell's machinery.
• Choose the organelle a virus must borrow by its function: the ribosome assembles proteins.
• Compare a virus and bacterium from a diagram and identify what each has and lacks.
• Sort traits into virus, cell, or both: genetic material belongs to both; obtaining and using energy belongs to cells; using a host to reproduce belongs to viruses; and maintaining homeostasis belongs to cells.

Watch out for

• Saying only that a virus needs a host cell is incomplete. Explain that it borrows cellular machinery such as ribosomes.
• Use organelle functions to eliminate structures that do not assemble proteins.