Structure And Function In Living Organisms - Part 1 (T2) Flashcards
How does a root hair cell in a plant contains specialised structures to carry out specific functions?
- they posses a long ‘finger-like’ protrusion with a very thin wall and a large surface area
- this is to absorb both water and mineral ions from the soil
Explain how leaf cells in plants are specialised structures to carry out specific functions…
- leaf cells contain chloroplasts which are tightly packed and regular in shape
- these form a continuous layer to ensure that absorption of sunlight is efficient
- the function of this structure is to absorb energy from light so the plant can photosynthesise
How are sperm cells specialised to carry out specific functions?
- the head of the sperm cell contains DNA and an enzyme which helps the sperm cell to penetrate the cell membrane of the ovum
- the middle section is full of mitochondria, which give the sperm cell energy
- the tail helps to transport the sperm cell to the egg
How is a red blood cell specialised to carry out its specific functions?
- a thin outer membrane allows easy diffusion of oxygen
- the outer membrane is also flexible allowing easy transport through narrow blood vessels
- the donut shape means there is a large surface area that allows the efficient absorption of oxygen
- there are no organelles so the cell can contain lots of haemoglobin
If a collection of similar cells stay together, carrying out the same function, this is called a what?
Tissue
In animals how do different tissues connect?
With connective tissue
If different tissues are grouped together for a purpose, what does this create?
And organ
When organs work together they form an… ?
Organ system
What is the definition of a cell?
The basic and functional unit of a living organism
What is the definition of an organelle?
A cell structure that is specialised to carry out a specific function or job
What is the definition of a tissue?
A group of cells with similar structures working together to perform a shared function
What is the definition of an organ?
A structure made up of a group of tissues working together to perform specific functions
What is the definition of an organ system?
A group of organs with related functions working together to perform body functions
Bones, nerves, muscles and epithelium are……
Tissue
A nucleus, mitochondria and cytoplasm are….
Organelles
The stomach, the lungs, the brain are all…
Organs
The skeleton, heart and blood vessels and alimentary canal are….
Organ systems
By how much can modern light microscopes magnify images?
1500 x
By how much can electron microscopes magnify images?
Around 2,000,000 x
What is the formula for calculation magnification?
Measured size / actual size
What is the formula for calculating actual size?
Measured size / magnification
Bradley describe simple diffusion..
- particles move from a region of high concentration to a region of low concentration
- particles move down what is known as a concentration gradient
Gives two examples of diffusion is the human body…
Location - gut
Particles - digested food products
From - gut cavity
To - blood in capillaries of villus
Location - lungs
Particles - oxygen
From - alveolar air space in the lungs
To - blood circulating around the lungs
Particles will continue to move from a high to low concentration whenever there is a….
Concentration gradient
What factors affect the rate of diffusion?
- concentration gradient: the greater the gradient the faster the rate of diffusion
- temperature and pressure: the higher the temperature and pressure the faster the rate
- size of particles: smaller particles diffuse faster
- distance: shorter distance = faster rate
- surface area to volume ratio: the larger this is the faster the rate of diffusion
