Cells Test Definitions Flashcards
(24 cards)
What is an organelle?
A sub cellular structure that has one or more specific jobs to perform in the cell
What are unicellular organisms?
Is a one cell organism
What is a multicellular organism?
Is a multi cell organism
What is photosynthesis?
Is the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar
What is the cell membrane?
A thin covering which surrounds the organelles inside the cells. Controls the passage of materials in or out of the cell. Outer boundary of an animal cell.
What is the cell wall?
Rigid structure that surrounds the cell membrane. Provides strength and support. Materials pass in and out of the cell through pores in the cell wall.
What are vacuoles?
Sac-like organelles that store excess food, waste, and other substances. Animal cells have several small vacuoles.
What is mitochondria?
The powerhouses of the cell. Break down food particles and release their stored energy. The cell uses this energy to fuel all of its activities. Number of mitochondria varies according to the function of the cell.
What is Golgi apparatus?
A folded organelle that combines proteins made by the endoplasmic reticulum. Delivers proteins to the rest of the cell.
What is cellular transport?
The movement of substances into and out of a cell is called cellular transport. Diffusion and osmosis are two types of cellular transport processes.
What are ribosomes?
Tiny organelles that help make proteins. There are many ribosomes in the cytoplasm. Add to the endoplasmic reticulum.
What are lysosomes?
Organelles which break down food and digest waste.
What is the endoplasmic reticulum?
A folded organelle that makes proteins?
What is nucleus?
A large organelle. The brain of the cell. Controls the activities of the cell, such as growth.
What are chloroplasts?
Contain a substance called chlorophyll. During photosynthesis, chlorophyll uses the suns energy to convert carbon dioxide and water into sugar (food) and oxygen.
What is the cytoplasm?
Jelly-like material that fills the cell and surrounds the organelle. Food and oxygen move through the cytoplasm to the organelles.
What is permeability?
Materials that are permeable allow for movement. Example: water and air passing through cotton. Materials that do not allow for movement are said to be impermeable. Example: plastic raincoats do not allow for water to get through.
What is osmosis?
Osmosis is a special kind of diffusion that involves only the movement of water through a selectively permeable membrane.
What is diffusion?
Diffusion is the movement of particles form an area where there are many of them (a higher concentration) to an adjoining area where there are few of them (a lower concentration). Diffusion continues until both areas have the same number (concentration) of particles. Example: smell of pizza, perfume. This is how resources such as oxygen are moved in and out of a cell.
What are the four differences between a plant and animal cell?
Plant Cell Animal cell
-has a cell wall -no cell wall
-has chloroplasts -no chloroplasts
-is a rectangular shape -circular shape
-is one large vacuole -several small vacuoles
What are the three basic ideas of cell theory?
- The cell is the basic unit if life
- An organism can be as simple as one (unicellular), like paramecium, or can be made up of trillions of cells (multicellular) like an elephant
- All cells are created from existing cells through a process called cell division (mitosis) by which a cell divides into two new cells
What are the differences between unicellular and multicellular organisms?
Unicellular Multicellular
-one cell -many cells
-microscopic -larger in size
-short lifespan -larger lifespan
-if injured it dies -if injured, it creates new cells
What are the levels of organization in the body?
Organelles
Cells
Tissue
Organs
Organ systems
Organisms
What is the difference between osmosis and diffusion?
Diffusion involves the movement of any molecules and does not require membrane, while osmosis is the movement of water through a semi-permeable membrane
