Cell Structure & Cell Diversity (chpt. 7 & 8) Flashcards
Protoplasm
All the living parts of a cell
Ultrastructure
The detail of a structure as seen using an electron microscope
Cell / plasma membrane
Controls passage of substances in and out of cell
Is semi - permeable
No definite shape
Composed of proteins and lipids - phospholipid bilayer
Phospholipid bilayer
Said to be fluid
Phospholipids and proteins
Nucleus
Control centre of cell
Contains chromosomes
Double membrane (nuclear pores)
Makes ribosomes
Cytoplasm
Where organelles are suspended
Location of metabolic activities
Cell wall
Only in plants
Gives shape and rigidity
Tough cellulose fibres
Vacuole
Large and permanent
Stores cell sap, a solution of salt & sugar
Mitochondria
Site of respiration
Chloroplasts
Plants only
Contains chlorophyll (photosynthesis)
Prokaryotic cells
Do not possess a membrane bound nucleus but contain a mass of DNA in cytoplasm (found as loops)
Do not have membrane bound organelles
E.g. bacteria
Eukaryotic cells
Have membrane around their DNA and possess a true nucleus. Have membrane bound organelles
Tissue
A group of similar cells that are adapted to carry out the same function
Plant tissues
Dermal tissue
A single later of cells that surrounds the outer surface of all plants
Protection
Waxy cuticle
Vascular tissue
Transports material around the plant
Xylem: water & minerals
Phloem: food from leaves to other areas
Animal tissues
Muscle
Found in muscles + many internal organs
Contracts
Contains mitochondria for respiration
Nervous tissue
Composed of nerve cells called neurons
Carry electrical impulses from the brain to the spinal cord
Covered by myelin sheath
Tissue culture
The growth of tissues in or on an artificial sterile medium outside an organism
Uses of tissue culture
Skin grafts, cancer research, micro propagation
Clone
A cluster of identical offspring
Organ
A structure composed of a number of tissues that work together to carry out one or more functions
Plants e.g. root, stem, leaf, flower
Animals e.g. heart, stomach, skin, liver, brain
System
A number of organs working together to carry out one or more functions
E.g. digestive, urinary, endocrine, skeletal, reproductive
DRAW plant cell, animal cell, active & inactive mitochondria, nucleus, phospholipid bilayer, chloroplast
Stain used for plant cells
Iodine
Stain used for animal cells
Methylene blue
What term is used to describe organisms that do not have nuclei?
Prokaryotes (prokaryotic)
What term is used to describe organisms whose cells contain a nucleus?
Eukaryotes (eukaryotic)
What type of microscope shows the most detail
Electron microscope
Selective permeability
Only certain substances allowed through
Where are ribosomes made?
Nucleus
Is a plant cell an example of a prokaryotic or eukaryotic cell? Why?
Eukaryotic
Contains membrane bound organelles (nucleus, mitochondria)
Name the most detailed microscope
Electron microscope
