cell specialisation Flashcards
1
Q
what is tissue
A
a collection of differentiated similar cells that have the same specialist function
2
Q
Main animal tissues
A
Nervous tissue
epithelial tissue
muscle tissues
connective tissues
3
Q
Main plant tissue
A
epidermal tissue
vascular tissue
4
Q
what is a muscle
A
tissue made of specialized cells which are capable of contracting in order to effect movement.
5
Q
What is an organ And give examples
A
a collection of tissue that carry out a particular function
e.g. heart, lungs, leaf
6
Q
What is an organ system
And give examples
A
Interconnected organs that carry out major functions of organism
Eg digestive/cardiovascular system
7
Q
in humans where are stem cells found
A
Early embryos, most in bone marrow, some everywhere, Umbilical cord
8
Q
Where are stem cells found in plants
A
meristem (Root tips and shoot tips)
9
Q
What are erythocytes cells And how they adapted to their function:
A
- Red blood cells
- have a flattened biconcave shape to increases their surface area to volume ratio to increase rate of diffusion
- they don’t have a nuclei which leaves space for more haemoglobin (molecule that binds to oxygen)
- no nucleus means it has a short life span
- Not many other organelles resulting in more space, but meaning no protein synthesis limited respiration and no reproduction
- flexible to squeeze through narrow capillaries
10
Q
What are neutrophils cells
A
- 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
11
Q
What are Sperm cells and how are they specialised to perform their function?
A
- 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
12
Q
what is the Squamous epithelium tissue
A
- 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
13
Q
What is the ciliated epithelium tissue
A
- Made up of ciliated epithelial cells (Which are also used to move egg from ovary to uterus)
- the cells have hair like structures called cilia on the surface Which beat to move mucus
- 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
14
Q
What is cartilage tissue
A
- 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
15
Q
What is muscle tissue
A
- 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
16
Q
what are palisade cells
A
- 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
17
Q
What are root hair cells
A
- 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
18
Q
What are guard cells
A
- 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
- the wall is thicker in the inner part close to the stoma
19
Q
What is the epidermis tissue
A
- 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
20
Q
What is the xylem tissue
A
- vascular tissue responsible for the transport of water and minerals from roots throughout the plant
- Composed of vessel made of elongated dead cells
- The walls of these cells are strengthened with a waterproof material called lignin providing structural support for plants
21
Q
What is the phloem tissue
A
- vascular tissue responsible for transport of 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 With companion cells next to them
22
Q
What does Totipotent mean
A
stem Cells that can differentiate into any type of cell
23
Q
What does pluripotent mean
A
stem cells that can differentiate into any type of human body cell
Embryonic stem cells are pluripotent
24
Q
What does multipotent mean
A
stem Cells that can differentiate into some types of human cells
Adult stem cells are multipotent
25
What does unipotent mean
stem Cells that can only differentiate into one type of cell
26
What are the two properties of stem cells?
They keep dividing (Go through mitosis) and they can differentiate to specialised cells.
27
What is cell therapy.
viable Cells injected/grafted/implanted into a patient with unviable cells
28
Get three possible uses of stem cells.
Growth repair research.
29
What is cell programming?
Changing what the cell does. by changing it back to a stem cell and then differentiating it.
30
What is therapeutic cloning.
Cloning an embryo for stem cells.
31
What is direct trans differentiation/ reprogramming?
Turning one specialised cell into another specialised cell without the stem cell step.
32
What is gene therapy?
Editing a mutation/genes
33
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.
34
What are the ethical issues with using embryonic stem cells for research
The embryo is destroyed and is discarded after use
the Embryo may have come from assisted fertilisation ivf
there is debate about when life begins
embryo cannot give consent
35
How stem cells are used in heart 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.
36
How can we use stem cells in research to gain biological knowledge
- They can be grown into different tissues to test how effective new medical drugs are Or how toxic and what their side effects are
- Or they can be studied to see how they Differentiate into different cell types And how cells function or what makes it fail to function properly due to certain diseases or cancer
