Cells & Specialisation Flashcards
Cells
Tiny, microscopic units.
All living things are made up of them
Cells
Animal Cell Structures
Cell Membrane Chromosomes Cytoplasm Mitochondria Nuclear Membrane Nucleus
Plant Cell Structures
Cell Membrane Cellulose Cell Wall Chloroplasts Chromosomes Cytoplasm Large Permanent Vacuole Mitochondria Nuclear Membrane Nucleus
Nucleus
3 marks
Control centre of the cell - containing genetic material
- arranged in the chromosomes of most cells.
Chromosomes
Threadlike structure.
Found in Nucleus.
Made of DNA - contains genetic info of cell.
Usually occur in functional pairs in the nucleus of cells (except gametes and bacteria).
Cytoplasm
The living substance inside a cell (not including the nucleus).
Chemical reactions take place here.
Mitochondria
Power house of the cell.
Site of Cell Respiration.
Abundant in cells that need energy
(E.g Muscle Cells)
They are Structures in the cytoplasm of all cells where aerobic respiration takes place.
Singular; mitochondrion.
Cell Membrane
Selectively permeable (semi-permeable) barrier.
Surrounds cell.
Allows some substances to enter/leave the cell.
Prevents others.
Nuclear Membrane
Surrounds Nucleus.
Cellulose Cell Wall
Rigid structure outside the Cell Membrane.
Against Cell Wall.
Provides support.
Large Permanent Vacuole
Found within the Cytoplasm; contains Cell Sap.
When full pushes Cell Membrane against Cell Wall.
Provides support.
Chloroplasts
Found in Leaf Cells.
Part of a cell that carries out photosynthesis.
Contains Chlorophyll
Chlorophyll
Green pigment that traps (sun)light in order to convert:
Carbon Dioxide + Water
into —>
Glucose (Chemical Energy) + Oxygen
in a process known as Photosynthesis
Bacteria
Single-celled organisms
Lack a nucleus;
Prokaryotes
Bacteria Structure
Cell Membrane
Cytoplasm
Non-cellulose Cell Wall
Plasmids
Do not contain a nucleus (prokaryotes)
Where are plasmids found in Bacteria?
Floating in cytoplasm.
Plasmids
Extrachromosomal DNA molecule (rings of DNA)
Found (floating) in Cytoplasm.
Stem Cells
Unspecialised cells found in plants and animals.
Have the ability to divide; to form cells of the same type.
Can differentiate into a variety of specialised cells.
Can be harvested from embryonic umbilical cord/adult bone marrow.
Embryonic Stem Cells
Can form a full range of cell types but many at an early stage will have changed permanently into specialised cells;
which can’t specialise into anything else.
Stem Cells from Bone Marrow
Only form a limited range of cell types (blood cells)
Stem Cells in Plants
Found in apical meristems at the end of shoots and roots.
Cells produced here = able to divide until they’re in their final position in root/stem/leaf.
Specialisation can still be reversed under certain conditions - meaning scientists are able to produce large no.’s of genetically identical plants in a short period of time through cloning.
Differentiate
When a cell becomes different in order to carry out a (particular) function.