Specialised Cells And Tissues Flashcards
What happens in complex multicellular organisms
Eukaryotic cells become specialised for specific functions
What do specialised cells have
Specific adaptations to help them carry out their functions
E.g the structure of a cell is adapted to carry out its function
What can structural adaptations include
The shape of the cell
The organelles that the cell contains (or doesn’t contain)
What is the function of erythrocytes
They transport oxygen around the body and carbon dioxide to the lungs
What is the 1st adaptation of erythrocytes
They are biconcave in shape increasing the SA over which oxygen can be absorbed
What is an adaption of erythrocytes 2
The cytoplasm contains high amounts of the pigment haemoglobin which readily binds to oxygen
What is an adaption of erythrocytes 3
No nucleus is present which makes more space inside the cell for haemoglobin molecules for maximum oxygen carrying capacity
What is an adaption of erythrocytes 4
Elastic membrane allows the cell to be flexible and change shape as it squeezes through narrow capillaries
What is the function for neutrophils
Destroy pathogens by phagocytosis and the secretion of enzymes
What is an adaption of neutrophils 1
Neutrophils have a very flexible shape that allows them to squeeze through cell junctions in the capillary wall
What is an adaption of neutrophils 2
Their flexibility also allows them to form pseudopodia - which engulf microorganisms
What is an adaption of neutrophils 3
Large number of lysosomes present in the cell. These digestive enzymes help to destroy invading cells.
What is an adaption of neutrophils 4
Flexible nuclear membrane helps the cell to penetrate cell junctions. This flexibility causes the characteristic of the lobed nucleus.
What is the function for stem cells
Reproduction - to fuse with an egg, initiating the development of an embryo and pass on the fathers genes
What is an adaption of sperm cells 1
The head contains a nucleus that contains half the normal number of chromosomes (haploid)
What is an adaption of sperm cells 2
The acrosome in the head contains digestive enzymes that can break down the outer layer of an egg cell, so that the haploid nucleus can enter to fuse with the egg’s nucleus.
What is an adaption of sperm cells 3
Mid-piece is packed with mitochondria to release energy from the tail movement
What is an adaption of sperm cells 4
The tail rotates, propelling the sperm cell forwards and allowing it to move towards the egg
What is the function of root hair cells
Absorption of water and mineral ions from soil
What is an adaption of root hair cells 1
Root hair to increase the surface area so the rate of uptake by osmosis is greater
What is an adaption of root hair cells 2
Thinner walls than other plant cells so that water can move through easily (short diffusion distance)
What is an adaption of root hair cells 3
Permanent vacuole contains cell sap which is more concentrated than soil water (maintaining a water potential gradient)
What is an adaption of root hair cells 4 & 5
Mitochondria for active transport of mineral ions
Chloroplast not found in these cells
What is the function of ciliates epithelium
Moving substances across the surface of a tissue
What is an adaption of ciliated epithelium 2
Have cilia, which beat in a coordinated way to shift material along the surface of the epithelium tissue
What is an adaption of ciliated epithelium 2
Goblet cells secrete mucus, which traps dust, dirt and microorganisms - preventing them entering vital organs where they can cause infection
What is the function for the squamous epithelial
Prove a surface covering or outer layer. Found on a verity of organs and structures (e.g alveoli. And blood vessels).
What is an adaption of squamous epithelial cells 1
Consists of a single layer of flattened cells on a basement membrane
What is an adaption of squamous epithelial cells 2
The layer of cells forms a thin cross-section which reduces the distance that the substance has to move to pass through - shorter diffusion distance
What is an adaption of squamous epithelial cells 3
Permeable - allowing for easy diffusion of gases
What is the function of palisade cells
Carry out photosynthesis producing oxygen and glucose
What is an adaption of palisade cells 1
A large number of chloroplasts are present in the cytoplasm to maximise the absorption of light for photosynthesis
What is an adaption of palisade cells 2
The tall and thin shape of the cells allows light to penetrate deeper before encountering another cell wall (cell walls absorb/reflect light) and for many cells to be densely packed together.
What is the function of guard cells
Control the opening of the stomata to regulate water loss and gaseous exchange
What is an adaption of guard cells 1
Inner cell walls are thicker (those that free the air outside the leaf) while the outer cell walls are thinner. The difference in thickness of the cell walls allows the cell to bend when turgid.
What is an adaption of guard cells 2
Cytoplasm has a high density of chloroplasts and mitochondria. These organelles may play a role in the opening of the stomata.
What do specialised cells of the same type group together to do
To form tissue
What is a tissue and an example
Is a group of cells that work together to perform a particular function:
For example (epithelial cells group together to form epithelial tissue (in the small intestine is to absorb food))
What do different tissues work together to form
Organs
What do organs work together to form
Organ systems
What is the function of xylem vessel cells (xylem tissue)
Transport tissue for water and dissolved ions
What are the adaptations of xylem cells in the tissue (1)
No top and bottom walls between cells to form continuous hollow tubes through which water is drawn upwards through the leaves by transpiration.
What are the adaptations of xylem cells in the tissue (2)
Cells don’t have organelles or cytoplasm to allow free movement of water
What are the adaptations of xylem cells in the tissue (3)
Outer cell walls are thickened with lignin, strengthening the tubes helping to support the plant
What is the function of phloem vessel cells
Transport of dissolved sugars and amino acids
What are the adaptations of the phloem vessel cells (1)
They are made up of living cells which are supported by companion cells
What are the adaptations of the phloem vessel cells (2)
Cells are joined end to end and contain holes in the end cell walls forming tubes that allow sugars and amino acids to flow easily through (by translocation)
What are the adaptations of the phloem vessel cells (3)
Cells have very few sub-cellular structures to aid the flow of materials
What is the function of muscle cells in the muscle tissue
Contraction for movement
What are the adaptations of muscle cells (1)
All muscle cells have layers of protective filaments in them, these layers can slide one each other causing muscle contraction
What are the adaptations of muscle cells (2)
Muscle cells have a high density of mitochondria to provide sufficient energy for muscle contraction
What are the adaptations of muscle cells (3)
Skeletal muscle cells fuse together during development to form multinucleated cells that contract in unison
What is the function of cartilage
To provide support
What are adaptions of the cartilage cells in cartilage tissue (1)
Cartilage is a strong and flexible tissue found in various places around the body
Where is cartilage found and what does it do there
Along the trachea in tracheal rings.
These help to support the trachea and ensure it stays open allowing it to move and flex while we breathe.
