Biology quiz Flashcards
Cell Theory
All living things are made up of one or more cells
The cell is the simplest unit that can carry out all life processes
All cells came from other cells and not non-living matter
Prokaryotic cells
Simplest type of cells
First type of cells to have evolved
Lack nucleus and membrane bound organelles
Eukaryotic cells
More complex than prokaryotic cells
Have many specialized parts called organelles
Cytoplasm
Plant and animal
Jelly like fluid
Provides an environment for chemical reactions to occur in the cell
Cell membrane
Plant and animal
Selective permeable phospholipid bilayer that isolates the cell interior from the exterior
Regulates what enters and exits the cell and has receptors that helps the cell communicate
Cell membrane diffusion moves particles from an are of high concentration to an area of low concentration until equal
Cell wall
Plant only
Rigid porous structure made of cellulose just outside the cell membrane in plant cells
Provides support and protection
Nucleus
Plant and animal
A roughly spherical organelle enclosed by a double membrane
Contains DNA which contains coded instructions for all cell proteins
Nucleolus
Plant and animal
Darker area inside the nucleus
Place where ribosomes are synthesized
Mitochondria
Double membrane bound organelle with a highly folded inner membrane
Power house of the cell where cellular respiration occurs
Cellular respiration: chemical process in which glucose is converted into carbon dioxide, water and energy
Chloroplast
Plant only
In plant cells that are exposed to light
Contains the green pigment - chlorophyll
Place where photosynthesis occurs
Golgi bodies
Plant and animal
A stack of membranes
Produces and packages substances for secretion out of the cell
Ribosomes
Plant and animal
Small structures(tiny little dots)
Protein synthesis occurs there
Vacuole
Plants and animals(larger in plants)
A membrane bound sac
Used for storage of water, waste, food etc
Plants have really large central vacuole full of water
Endoplasmic reticulum
Plants and animals
A system of membranes (like tubes and pockets)
Used for transport of material in the cell
Lysosome
Animal only
Small vesicle containing digestive enzymes
“Suicide sac”
Cilia
Animal only
Hair like structures
Used for movement
Flagellum
Animal only
Whip like “tail” used for movement
Centrioles
Animal only
Tubules at right angles to each other
Organize spindle fibre during cell division
Reasons for cell division not related to reproduction
Growth
Repair
Maintenance
Interphase
G1, S, G2
Part of cell cycle when cell performs its normal functions and DNA is copied for cell division
Mitosis
And 4 stages
Part of the cell cycle when the DNA in the nucleus is divided
- Prophase
- Metaphase
- Anaphase
- Telophase
Cytokinesis
The stage in the cell cycle when the cytoplasm divides to complete cell division
Daughter cells
2 genetically identical nee cells formed when one parent cell divides
Chromosomes
Every cell contains chromosomes(formed from chromatin)
Each chromosome is a long piece of coiled DNA and proteins
I.e. humans have 46 chromosomes,hermit crabs have 254
For mitosis to occur, each chromosome must be copied. The identical copies are called sister chromatids
Stages of mitosis
Early prophase
Late prophase
Metaphase
Anaphase
Telophase
Stage 1
Early prophase
Chromatin shortens and thickens (condenses) to make chromosomes
Nucleolus disappears
Spindle fibres form
Stage 2
Late prophase
Individual chromosomes can now be seen
Each consists of two identical sister chromatids
The nuclear membrane is breaking down
Stage 3
Metaphase
Chromosomes are connected to the spindle fibre at its centromere
Chromosomes line up at the equator of the cell
Stage 4
Anaphase
Centromere splits, and the sister chromatids separate and move to opposite poles of the cell
This pull occurs due to spindle fibres shortening
Stage 5
Telophase
Daughter chromosomes reach the poles and start to unravel(lose condensed form)
Nuclear membrane forms and spindles have disappeared
Stage 5ish
Cytokinesis
Occurs during telophase
Cell membrane pinches in and cytoplasm divides
After cytokinesis - two new daughter cells enter interphase
