specialised cells + tissues Flashcards
How are erythrocytes specialised for carrying oxygen? (3)
Biconcave shape increases surface area for gas exchange
No nucleus allows more space for haemoglobin to carry oxygen
Flexible to fit through narrow capillaries
How are neutrophils specialised to fight infections? (3)
Multi-lobed nucleus helps them squeeze through gaps to reach infection sites
Flexible shape allows them to engulf foreign pathogens
Granular cytoplasm contains lysosomes with digestive enzymes to break down engulfed particles
What is the function of epithelial cells? (2)
Epithelial cells cover organ surfaces
Are joined by interlinking cell membranes with a base membrane
How are squamous epithelial cells specialised? (3)
Found in lungs
They are very thin
Providing a short diffusion pathway for gas exchange
How are ciliated epithelial cells specialised? (2)
Found in airways
They have cilia that beat to move particles away from the lungs
How are sperm cells specialised for delivering genetic information to the female gamete? (3)
Flagellum: Enables swimming towards the egg
Lots of mitochondria: Provides energy to swim
Acrosome: Contains digestive enzymes to penetrate the egg’s surface for fertilisation
How are palisade cells specialised for photosynthesis? (4)
Many chloroplasts: for maximise sunlight absorption
Chloroplasts can move: to absorb more light as needed
Rectangular shape: allows close packing to form a continuous layer
Thin walls: has a short diffusion distance for carbon dioxide
How are root hair cells specialised for absorbing water and minerals? (3)
Long extensions: Large surface area for absorption.
Thin, permeable cell walls: Allows easy entry of water and ions.
Lots of mitochondria: Provides ATP for active transport of minerals.
How are guard cells specialised for regulating gas exchange? (3)
Found in pairs: Form a stoma (gap between them).
Become turgid in light: Opens stomata for gas exchange
Thin outer walls and thick inner walls: Cause bending outward, opening the stomata to allow gas exchange for photosynthesis.
How are cells organised into tissues, organs, and organ systems? (4)
Specialised cells group together to form tissues.
A tissue is a group of cells working together to perform a particular function
Different tissues work together to form organs
Different organs make up an organ system.
What is squamous epithelium? (2)
A single layer of flat cells lining a surface
Found in places where rapid exchange is essential, such as the alveoli in the lungs
What is ciliated epithelium? (3)
A layer of cells covered in cilia
Found in places where substances need to be moved
Such as the trachea to move mucus away from the lungs.
What are muscle tissues made of? (1)
Bundles of elongated cells called muscle fibres
What are three different types of muscle tissues? (3)
Smooth (e.g., stomach wall)
Cardiac (found in the heart)
Skeletal (used for movement)
What is cartilage? (3)
A type of connective tissue found in joints, firm and flexible
It also shapes and supports the ears, nose, and windpipe
Formed when chondroblasts secrete an extracellular matrix and become trapped inside
What is xylem tissue? (3)
A type of vascular tissue that transports water and supports the plant
Contains dead, hollow xylem vessels and living parenchyma cells
Xylem walls are strengthened with lignin, making them waterproof.
What is phloem tissue? (3)
A type of vascular tissue that transports sugars around the plant
Consists of sieve cells and companion cells
Sieve cells have end walls called sieve plates to allow sap to move through easily
