cell specialisation Flashcards
what is tissue
a collection of differentiated similar cells that have the same specialist function
Main animal tissues
Nervous tissue
epithelial tissue
muscle tissues
connective tissues
Main plant tissue
epidermal tissue
vascular tissue
what is a muscle
tissue made of specialized cells which are capable of contracting in order to effect movement.
What is an organ And give examples
a collection of tissue that carry out a particular function
e.g. heart, lungs, leaf
What is an organ system
And give examples
Interconnected organs that carry out major functions of organism
Eg digestive/cardiovascular system
in humans where are stem cells found
Early embryos, most in bone marrow, some everywhere, Umbilical cord
Where are stem cells found in plants
meristem (Root tips and shoot tips)
What are erythocytes cells:
- Red blood cells
- have a flattened biconcave shape to increases their surface area to volume ratio to transport more oxygen around the body
- they don’t have a nuclei which leaves space for more haemoglobin (molecule that binds to oxygen)
- they are very flexible so they are able to squeeze through the narrow capillaries
What are neutrophils cells
- Type of white blood cells that play a role in the immune system
- they have multi lobed nucleus which makes it easier for them to squeeze through small gaps to get to sites of infections
- the granular cytoplasm contains many lysosomes that contains digestive enzymes to attack pathogens
What are Sperm cells and how are they specialised to perform their function?
- Male gametes that deliver genetic information to the female gamete
- sperm have a tail or flagellum so they are able to move/ swim
- they contain many mitochondria to supply energy needed to move/swim
- the acrosome on the head contains Digestive enzymes which are released to digest the protective layers around the egg and allow the sperm to penetrate leading to fertilisation
what is the Squamous epithelium tissue
- Made up of squamous epithelial cells and known as pavement epithelium due to flat appearance
- it is very thin because there’s one cell thick
- Present where rapid diffusion across the surface is essential
- forms the lining of the lungs and allows rapid diffusion of oxygen into the blood
What is the ciliated epithelium tissue
- Made up of ciliated epithelial cells
- the cells have hair like structures called cilia on the surface
- goblet cells are also present releasing mucus to trap any unwanted particles in the air which prevents the particles (may be bacteria) from reaching the Alveoli
- it lines the trachea causing mucus to be swept away from the lungs
What is cartilage tissue
- Connective tissue found in outer ear nose and between bones
- contains fibres of the protein; elastin and collagen
- its firm and flexible
- composed of chondrocyte cells embedded in an extracellular matrix cartilage Which contains elastin
- prevents the ends of bones from rubbing together and causing damage
What is muscle tissue
- is responsible for the movements of bones
- Muscle tissue needs to be able to shorten in length in order to move bones which in turn moves the different parts of the body
- there are different types of muscle fibres; skeletal muscle fibres (muscles which are attached to the bone) contain myofibrils which contain contractile proteins
what are palisade cells
- Present in plant mesophyll
- contain chloroplasts Which can move within the cytoplasm to absorb large amounts of sunlight for photosynthesis
- can be closely packed to form a continuous layer
- have thin cell walls increasing rate of diffusion of carbon dioxide
- large vacuole to maintain turgor pressure
What are root hair cells
- Present at the surfaces of roots tips
- are long and thin which increases surface area And allows for faster uptake of water and minerals from soil
What are guard cells
- Pairs of cells on the surface of leaves forming small openings called stomata
- Allows water vapour and oxygen in and out
- necessary for carbon dioxide to enter plants for photosynthesis
- When guard cells loose water and become less swollen, they change shape and stoma closes to prevent further water loss
What is the epidermis tissue
- A single layer of closely packed cells covering the surface of plants
- Covered by waxy waterproof cuticle to reduce the loss of water
- guard sells a present in the epidermis allowing carbon dioxide in and out and water vapour and oxygen in and out
What is the xylem tissue
- a type of vascular tissue responsible for the transport of water and minerals throughout the plant
- Composed of vessel element which are elongated dead cells
- The walls of these cells are strengthened with a waterproof material called lignin providing structural support for plants
What is the phloem tissue
- Another type of vascular tissue responsible for transport of organic nutrients (particularly sucrose) from leaves and stems (where it is made by photosynthesis) to all parts of the plant where it is needed
- Composed of columns of sieve tube cells separated by perforated walls called sieve plates
What does Totipotent mean
stem Cells that can differentiate into any type of cell
What does pluripotent mean
stem cells that can differentiate into any type of human body cell
What does multipotent mean
stem Cells that can differentiate into some types of human cells
What does unipotent mean
stem Cells that can only differentiate into one type of cell
What are the two properties of stem cells?
They keep dividing and they can differentiate to a specialised cell.
What is cell therapy.
viable Cells injected grafted implanted into a patient
Get three possible uses of stem cells.
Growth repair research.
What is cell programming?
Changing with the cell does. by changing it back to a stem cell and then differentiating it.
What is therapeutic cloning.
Cloning an embryo for stem cells.
What is direct trans differentiation/ reprogramming?
Turning one specialised cell into another specialised cell without the stem cell step.
What is gene therapy?
Editing a mutation/genes
What are advantages and disadvantages of using embryonic stem cells for medical research?
Advantages;
We use embryos that would have been wasted, It would help the curing of disease, improves quality of life.
Disadvantages;
Not ethical, religious objections, are later on destroyed.
How stem cells are used in medicine?
If heart cells are damaged, body is unable to sufficiently replace the damaged cells.
With Alzheimer’s. nerve cells in the brain die resulting in memory loss. Stem cells could be used to regrow healthy nerve cells.
Patients with Parkinson’s face Uncontrollable tremors Due to a loss of certain type of brain’s nerve cell Which releases a chemical called dopamine, which is needed to control movement. transplanted stem cells can help to regenerate the dopamine producing cells.
