Specialised Cell And Stem Cells Flashcards
(33 cards)
How are red blood cells (erythrocytes specialised?
Have flattened biconcave shape to increase SA:V ratio
No nuclei to increase space available for haemoglobin to carry the maximum load of oxygen.
Flexible so they can squeeze through capillaries
How big are erythrocytes?
7.5 micrometers from above
2 micrometers from the side view
How are neutrophils specialised?
Play an essential role in immune system.
Multi lobed nucleus to make it easier to squeeze through small gaps to get to the site of infections.
Granular cytoplasm which has many lysosomes that contains enzymes used to attack pathogens.
How large are neutrophils?
10-14 micrometers
How are sperm cells specialised?
Have a tail or flagellum so that they are capable of movement
Contain many mitochondria to provide the energy required for swimming.
Acrosome contains digestive enzymes which are released to digest the protective layers around the ovum and allow the sperm to penetrate leading to fertilisation.
How are palisade cells specialised?
Contain chloroplasts to absorb large amount of light for photosynthesis
Rectangular box shapes so that can be closely packed together to form a continuous layer.
Thin walls to increase the rate of diffusion of carbon dioxide.
Chloroplasts can move within the cytoplasm to absorb the maximum amount of light.
How are root hair cells specialised?
Long extensions called root hairs which increases the surface area of the cell to maximise water and mineral uptake from the soil.
How large are sperm cells?
3 micro meters wide and 4 micrometers long
How large are palisade cells?
25-75 micrometers
How large are root hair cells?
20-150 micrometers
How are pairs of guard cells specialised?
Control stomata opening.
Cell wall of the guard cell is thicker on one side so the cell does not change shape symmetrically as it’s volume changes.
What are the 4 main categories of tissues in animals?
Nervous tissue
Epithelial tissue
Muscle tissue
Connective tissue
How large are guard cells?
15-20 micrometers
How is squamous epithelial tissue specialised?
Very thin due to the squat or flat cells that make it up and it’s also one cell thick.
Present in tissues where rapid diffusion across surfaces is essential.
Forms the lining of the lungs to allow for rapid diffusion of oxygen into the blood.
What is ciliates epithelium and how is it specialised?
Cells have hair like structures called cilia that move in a rhythmic manner.
This lines the trachea, causing mucus to be swept away from the lungs.
Goblet cells also present to release the mucus to trap unwanted particles, preventing this bacteria from reaching the alveoli.
What is cartilage tissue and how is it specialised?
Connective tissue found in the outer ear, nose and at the ends of bones.
Contains fibres such as elastin and collagen. Cartilage is a firm, flexible connective tissue.
Prevents the ends of bones from rubbing together and causing damage.
What is muscle and how is it specialised?
A tissue that needs to be able to contract in order to move bones.
Different types of muscle fibres including skeletal muscles which are attached to bones.
Skeletal muscles contain myofibrils which contain contractile proteins.
Individual muscle fibres separated by connective tissue
Importance of the epidermis in plants?
Single layer of closely packed cells covering the surface of plants.
Usually covered by a thick waxy cuticle to prevent water loss by transpiration.
Stomata are present here, they allow CO2 in and out and water vapour and oxygen in and out.
Importance of Xylem tissue in plants?
Responsible for the transport of minerals and water throughout plants.
Composed of vessel elements which are elongated dead cells.
Walls are strengthened with lignin(pink rings on micro graphs) which provides structural support.
What is the importance of phloem tissue?
Vascular tissue in plants responsible for the transport of organic nutrients and sucrose.
Transport from leaves of plants where it is made by photosynthesis to all parts of the plant where it is needed.
Composed of sieve tube cells separated by perforated walls called sieve plates
What is an organ?
A collection of tissues which are adapted to perform a specific function in an organism.
Animal examples of coordinated organ systems?
Digestive system - takes in food, breaks it down, absorbs nutrients, retains water and removes waste.
Cardiovascular system - moves blood around the body to provide an effective transport system for the substances it carries.
Gaseous Exchange system - brings air into the body so that oxygen can be extracted for respiration and CO2 can be expelled
What are stem cells?
Undifferentiated cells which are not adapted to any particular function.
Why are stem cells good?
Are a source of new cells necessary for growth, development and tissue repair.
