Specialised cells 2.1.6 (h,i) Flashcards
What is an erythrocyte?
They are red blood cells which carry oxygen around the body.
- They have a biconcave disc shape which gives it a larger surface area
- no nucleus and a lack of organelles in order to have more space for haemoglobin.
What is a neutrophil?
They have a flexible shape which allows them to engulf foreign pathogens.
-They contain many lysosomes in their cytoplasm which break down engulfed pathogens.
What are sperm cells?
They are male gametes. They deliver genetic information to the female egg.
- They have a flagellum which allows them to move.
- It contains a lot of mitochondria in order to power movement.
- It’s head contains acrosome which contains digestive enzymes which allow the sperm cell to penetrate the egg.
What are palisade cells?
They are found in the mesophyll.
- Contain a lot of chloroplast in order to absorb as much light as possible for photosynthesis.
- They have thin cell walls to increase the rate of diffusion of carbon dioxide
- They have a large vacuole to maintain turgor pressure
What are root hair cells?
They are found at the surface of roots
- They have root hairs which increase the surface are of the cell to maximise uptake of water and minerals
What are guard cells?
Found on surfaces of leaves. They form small openings called stomata which allow for carbon dioxide to enter the plant for photosynthesis.
- They can lose water to become less swollen which closes to prevent water loss
What is a tissue?
A collection of specialised cells
What are the 4 main tissue categories in animals?
- nervous tissue
- epithelial tissue
- muscle tissue
- connective tissue
What is the squamous epithelial tissue?
Made up of squamous epithelial cells.
- has a flat appearance
- very thin (one cell thick) which provides rapid diffusion
Forms the lining of the lungs which allows for rapid diffusion of oxygen into the blood.
What is the ciliated epithelium tissue?
Made up of ciliated epithelial cells
- cells have cilia which push mucus down the throat
- lines the trachea which prevents the mucus from reaching the lungs
- contains goblet cells which release mucus to trap unwanted particles in the air
What is the cartilage tissue?
Found in the outer ear, nose and between bones. It contains elastin and collagen.
- cartilage is a firm and connective tissue made up of chondrocyte cells
Prevents bones from rubbing together and causing damage
What is the muscle tissue?
Function is to contract and retract to move bones.
- contain contractile myofibrils which contain contractile proteins
What are the 2 types of plant tissue?
- Epidermis tissue
- Vascular tissue
What is the xylem tissue?
A vascular tissue responsible for water and minerals in plants
- tissue composed of vessel elements which are elongated dead cells
- the walls are strengthened by lignin which is waterproof and provides structural support for plants
What is the phloem tissue?
A vascular tissue in plants which transports organic nutrients from leaves and stems (where it is made) to the rest of the plant.
- composed of columns of sieve tube cells separated by perforated walls called sieve plates
