Biology Chapter 7 Flashcards
Who was first to find cells?
Anton van Leeuwenhoek
What is the structure that makes up all living things?
Cells
What did Robert Hooke describe cells as?
Tiny, empty rooms
Who concluded that all plants are made of cells? Animals?
Plants- Matthias Schleiden
Who concluded that cells divide to reproduce?
Rudolph Virchow
What makes up the cell theory?
- All living things have cells
- Cells are the basic unit of structure and function in living things.
- New cells are produced from existing cells
What makes electron microscopes able to scan in so much more detail?
Small wavelengths
What is a prokaryote? Give an example.
Organisms with no nuclei
Ex: Bacteria
What is a eukaryote?
Organisms with nuclei
What is an organelle?
Structures that are like specialized units in eukaryotic cells.
True or false: Only plant cells have chloroplasts and cell walls.
True
What does the nucleus contain that instructs how to make proteins and other important molecules?
DNA
What is chromatin?
Granular material visible in the nucleus.
What are chromosomes?
Condensed chromatin that forms a threadlike structure that contains genetic information that is passed through cells.
What is the small, dense region in the center of the nucleus?
Nucleolous
What is the nuclear envelope?
The two membranes that regulate what passes in and out of the nucleus.
What are ribosomes?
Small particles of RNA found throughout the cytoplasm.
What is the difference between smooth and rough endoplasmic reticulum?
Rough has ribosomes scattered across the surface.
What organelle modifies, sorts, and packages proteins?
Golgi apparatus
What organelle breaks down old organelles, lipids, carbs, and proteins?
Lysosomes
What kind of materials do vacuoles store?
Water, salts, proteins, and carbs
Why is there a central vacuole in plant cells?
To support heavy objects like leaves and flowers
How do contractile vacuoles help maintain homeostasis?
Consistently pumps out water
What function does a mitochondria organelle perform?
Convert chemical energy from food into compounds for the cell to use.
What is the support structure of a cell?
Cytoskeleton
What two structures make up the cytoskeleton? What do they do?
Microfilaments- Threadlike structures of actin, a protein, that maintain cell shape, form centrioles, and help build cilia and flagella
What does the cell membrane do?
Regulates what moves in and out of cells and provides protection and support
What is the core of nearly all cell membranes?
The lipid belayer
What do proteins and carbohydrates do in the cell membrane?
Proteins- move materials
Carbs- Identify other cells
Is the cell membrane inside or outside the cell wall?
Inside
What mostly makes up cell walls?
Fibers of carbs and proteins
What is concentration?
The mass of solute in a solution
What is diffusion?
When particles evenly fill a substance.
When does a substance reach equilibrium?
All of the solution has an equal amount of solute.
True or false: When equilibrium is reached, particles still move through the membrane but they move evenly.
True
What does it mean when a membrane is selectively permeable?
Some things can go through, some cannot
What is osmosis?
The diffusion of water through a selectively permeable membrane
What does it mean when a solution is isotonic?
Both solute are the same strength
When is a solute hypertonic? Hypotonic?
Hypertonic- solute is above strength
Hypotonic- solute is below strength
True or false: Osmosis exerts a pressure on the hypertonic side of a selectively permeable membrane.
True
What is facilitated diffusion?
When specific molecules move through protein channels in a cell membrane
What do protein channels do?
Allow materials through the cell membrane
True or false: Facilitated diffusion requires energy.
False
What process moves material across a cell membrane that requires energy?
Active transport
What are the three types of active transport? Briefly describe each.
Endocytosis- moves material using infoldings (pockets) of the cell membrane
Phagocytosis- extensions of cytoplasm surround a particle and package it within a food vacuole
Exocytosis- when vacuole membranes fuse with the cell membrane and release liquid into the cell membrane
What forms during endocytosis?
A vacuole
What is a group of cells that form a similar function called?
Tissue
