Prokaryotes include smaller and simple cells like bacteria
The cytoplasm contains enzymes
Aerobic respiration takes place in the mitochondria
Bacteria cells contain loops of DNA called plasmids
Electron microscopes have higher magnification and resolution
magnification formula
magnification=image size/real size
Differentiation is the process by which a cell changes to become specialised for its job
6 types of specialised cells
Sperm, Muscle, Nerve, Root, Phloem, Xylem
Before a cell divides what does it first do
Cell has to grow and increase amount of mitochondria and ribosomes
After the increase in subcellular strucutres what happens next?
DNA duplicates
What does duplication of DNA form
X-Shaped Chromosomes
Describe the first stage of mitosis
Chromosomes line up at centre of the cell and cell fibres pull them apart, 2 arms of each chromosome go to opposite ends of the cell,
Describe the second stage of mitosis(after chromosomes have been pulled apart.
Membranes form around each set of chromosomes, these become the nuclei of 2 new cells
Describe the last part of mitosis
Cytopasm and membrane divide to form 2 new identical daughter cells.
Summarise Cell Cycle
Genetic material doubles then divides into 2 cells
Define Mitosis
Cell division forming 2 identical daughter cells
Prokaryotic Cells replicate using
Binary Fission
What happens in the first stage of Binary Fission
The circular DNA and plasmids replicate
Second Stage of Binary Fission
The cell gets bigger and the circular DNA strands move to opposite poles of the cell
Third Stage of Binary Fission
The cytoplasm begins to divide and the new cell wall begins to form
Fourth stage of Binary Fission
The cytoplasm divides and two daughter cells are produced. Each daughter cell has one copy of the circular DNA, but have different numbers of Plasmids.
Stems cells are found in
Humanembryos and Bonemarrow
Adultstemcells unlike embryonicstemcells can only turn into certain cells
In plants stem cells are found in the
Meristem
These plant stem cells have 3 main uses
To produce clones
To grow more plants of a rarespecies(prevent extinction)
To produce clones with desiredfeatures
Definition of Diffusion
Spreading out of particles from aan area of high concentration to an area of low concentration
Definition of Osmosis
The movement of water molecules across a partially permeable membrane from an region of high concentration to an region of lower concentration.
Definition of Active Transport
The process of moving molecules against a concentration gradient, from a region of lower concentration to a region of higher concentration, using energy.
Active transport is commonly used in
Root hair cells and the gut
Adaptations of Alveoli
Large surface area
Moist Lining for dissolving gases
Thin walls
Good blood supply
The strucutre of Leaves are adapted to let gasesdiffuseinandoutofcells