Please enable JavaScript.
Coggle requires JavaScript to display documents.
Biology- Unit 1 Cells, Stem Cells, Prokaryotic Cells, Bacterial Cells,…
-
Stem Cells
Adult Stem cells
- Adult stem cells can be found in certain areas such as the bone marrow
- However, they can't turn into any cell type
- For example bone marrow differentiate into different types of blood cells
- Found in differentiated tissue (bone, skin)
Their uses
-
- Potential growing new tissues that are genetically matched to the patient
Advantages
-
- Will not be rejected if stem cells came from own patient
- Replace faulty cell with healthy cell, so person is well again
Disadvantages
- Can only differentiate into certain cell types
- Invasive procedure to remove and requires consent
-
Embryonic Stem Cells
- Embryonic stem cells can differentiate into any type of cell
- They are taken from an embryo at every early stage of division
- Most animal cells lose their ability to differentiate into any cell type early on
Their uses
- Replacing or repairing brain cells to treat people with Parkinson disease
- Replacing damaged cells in the retina to treat someone with blindness
- Growing new tissues in the lab to use for transplants or drug testing
Advantages
- Can become many different types of cell
- Easy to extract from embryo
- Not an invasive procedure to remove
- Can be obtained from IVF clinics
Disadvantages
- Ethical issues with destroying potential life
-
- May be rejected by the new body
- May be infected by viruses in the lab
Plant Stem Cells
- Stem cells are found in the meristems
- Throughout the plant's life cells in the meristem tissues can differentiate into any type of plant cell
- Can be used to produce clones of whole plants quickly and cheaply
- Help preserve rare species and grow crops with specific desired features
- A meristem is the region of plant tissue which contains plant stem cells
All Stem Cells
- Stem cells are cells which are undifferentiated
- They can divide to produce more stem cells or undergo differentiation to produce different types of specialised cells depending on their environment
Uses
- Transfer stem cells from the bone marrow of a healthy person to replace faulty blood cells in a patient
- Differentiate embryonic stem cells to insulin producing stem cells for diabetic people or to nerve cells for people paralysed by spinal injuries
- Use therapeutic cloning to produce stem cells with the same genetic information as the patient so they are not rejected by the patient's immune system
-
Cloning
- Embryonic stem cells are produced with the same DNA as the patient so it is not rejected from their body this is theraputic cloning
- Reasons for cloning plants:
- cloning rare species to prevent extinction
- producing crop plants with special features such as disease resistance
-
Other info: Embryos from stem cell research are often obtained from fertility clinics where they would be thrown away anyway
Prokaryotic Cells
-
Prokaryotic cells do not have mitochondria, chloroplasts or a nucleus
-
-
-
-
Bacterial Cells
-
-
Instead they have a circular strand of DNA, floating freely in the cytoplasm
-
-
Eukaryotic Cells
They are found in animal, plant, fungi and protists
-
-
-
Plant cell
-
Plant cells have vacuoles, these are small and temporary
-
Microscopes
-
Electron Microscopes
-
-
-
used to see internal structure of mitochondria and chloroplasts, also small structures such as plasmids and ribosomes
-
-
Binary Fission
The process
- The circular DNA and the plasmids replicate
- The cell gets bigger and the circular DNA strands move to opposite poles of the cell
- The cell begins to divide and a new cell wall and membrane begins to form
- The cytoplasm divides and 2 new daughter cells are produced
-
-
Movement of Particles
Diffusion
- Diffusion is the movement of particles from a higher concentration to a lower concentration
- Increasing the temperature increases the rate of diffusion, as the particles have more kinetic energy and therefore move faster
- The shorter the diffusion distance, the faster the rate of diffusion
- The larger the surface area the faster the rate of diffusion as more particles can go through at once
Examples of Diffusion
- Carbon dioxide moving from the blood into the alveoli
- Oxygen moving from the alveoli into the blood
Osmosis
- In osmosis the water molecules move through a partially permeable membrane
Examples of Osmosis
- Root hair cells absorbing water
- Water being reabsorbed in the large intestine
Active Transport
-
-Active transport is the movement of molecules against the concentration gradient using energy transferred from respiration
-
-
-
-
-
-
-
Cell wall- made of cellulose, it provides strength and support
-
Chloroplasts- contains chlorophyll, where photosynthesis happens
-
-
-
