6.1: Exchange between organisms and their environment Flashcards
The external environment is different from the internal environment found within what?
The external environment is different from the internal environment found:
- Within an organism
- Within its cells
The external environment is different from the internal environment found within an organism and within its cells.
To survive, organisms transfer materials between the 2 environments.
This transfer takes place at exchange surfaces and always involves what?
This transfer:
- Takes place at exchange surfaces
- Always involves crossing cell plasma membranes
Tissue fluid
Tissue fluid is the environment around the cells of multicellular organisms
Tissue fluid
Tissue fluid is the environment around the cells of multicellular organisms
The external environment is different from the internal environment found within an organism and within its cells.
To survive, organisms transfer materials between the 2 environments.
This transfer takes place at exchange surfaces and always involves crossing cell plasma membranes.
The majority of cells are too far from exchange surfaces for diffusion alone to supply or remove their tissue fluid with the various materials needed to keep its composition relatively constant.
Therefore, once absorbed, materials are rapidly distributed to the tissue fluid and the waste products returned to the exchange surface for removal.
This involves a mass transport system.
It is this mass transport system that maintains the diffusion gradients that do what?
It is this mass transport system that maintains the diffusion gradients that bring materials:
1. To
2. From
the cell-surface membranes
In a mass transport system, what do all the substances do?
In a mass transport system, all the substances move in the same direction at the same speed
In a mass transport system, all the substances move in the same direction at the same speed.
Example
For example, the:
- Mammalian circulatory system
- Vascular system of a plant
In a mass transport system, all the substances move in the same direction at the same speed.
Mass transport systems are just as important for what as they are for supplies?
Mass transport systems are just as important for the rapid removal of waste as they are for supplies
In a mass transport system, all the substances move in the same direction at the same speed.
Mass transport systems are just as important for the rapid removal of waste as they are for supplies.
Even what can take place via a mass transport system?
Even communication from one cell to another can take place via a mass transport system
In a mass transport system, all the substances move in the same direction at the same speed.
Mass transport systems are just as important for the rapid removal of waste as they are for supplies.
Even communication from one cell to another can take place via a mass transport system.
Example
For example, hormones in a blood stream
In a mass transport system, all the substances move in the same direction at the same speed.
Mass transport systems are just as important for the rapid removal of waste as they are for supplies.
Even communication from one cell to another can take place via a mass transport system.
The greater the what of an organism, the greater the demands on its mass transport system?
The greater the metabolic rate of an organism, the greater the demands on its mass transport system
The what of an organism will affect the amount of each material that is exchanged?
The:
1. Size
2. Metabolic rate
of an organism will affect the amount of each material that is exchanged
The size and metabolic rate of an organism will affect the amount of each material that is exchanged.
Example
For example, organisms with a high metabolic rate:
- Exchange more materials
- So require a larger SA:V ratio
The size and metabolic rate of an organism will affect the amount of each material that is exchanged.
For example, organisms with a high metabolic rate exchange more materials and so require a larger SA:V ratio.
In turn, this is reflected in what?
In turn, this is reflected in the type of:
1. Exchange surface
2. Transport system
that evolved to meet the requirements of each organism
Examples of things that need to be interchanged between an organism and its environment include what?
Examples of things that need to be interchanged between an organism and its environment include:
- Respiratory gases
- Nutrients
- Excretory products
- Heat
Examples of things that need to be interchanged between an organism and its environment include respiratory gases (what), nutrients, excretory products and heat?
Examples of things that need to be interchanged between an organism and its environment include:
- Respiratory gases (oxygen and carbon dioxide)
- Nutrients
- Excretory products
- Heat
Examples of things that need to be interchanged between an organism and its environment include respiratory gases (oxygen and carbon dioxide), nutrients (what), excretory products and heat?
Examples of things that need to be interchanged between an organism and its environment include:
- Respiratory gases (oxygen and carbon dioxide)
- Nutrients (glucose, fatty acids, amino acids, vitamins and minerals)
- Excretory products
- Heat
Examples of things that need to be interchanged between an organism and its environment include respiratory gases (oxygen and carbon dioxide), nutrients (glucose, fatty acids, amino acids, vitamins and minerals), excretory products (what) and heat?
Examples of things that need to be interchanged between an organism and its environment include:
- Respiratory gases (oxygen and carbon dioxide)
- Nutrients (glucose, fatty acids, amino acids, vitamins and minerals)
- Excretory products (urea and carbon dioxide)
- Heat
Examples of things that need to be interchanged between an organism and its environment include respiratory gases (oxygen and carbon dioxide), nutrients (glucose, fatty acids, amino acids, vitamins and minerals), excretory products (urea and carbon dioxide) and heat.
Except for heat, these exchanges can take place in how many ways?
Except for heat, these exchanges can take place in 2 ways:
1. Passively
Or,
2. Actively
Examples of things that need to be interchanged between an organism and its environment include respiratory gases (oxygen and carbon dioxide), nutrients (glucose, fatty acids, amino acids, vitamins and minerals), excretory products (urea and carbon dioxide) and heat.
Except for heat, these exchanges can take place in 2 ways - Passively (no what is required) or actively?
Except for heat, these exchanges can take place in 2 ways:
1. Passively (no metabolic energy is required)
Or,
2. Actively