3.3 Flashcards
What kind of structures do all land plants have?
structures below ground that absorb water and minerals, structures above ground that photosynthesize, and structures that link the two together
What system do vascular plants have for absorption?
Organ and organ systems
What systems do vascular plants have for transport and photosynthesis?
Roots, stems, and leaves
How are roots, stems, and leaves organized in two systems?
The shoot system: stems and leaves above ground
The root system (below ground)
What do shoot systems (stems and leaves) do?
Photosynthesize sugars, conserve water, provide aerial support at different levels
What do root systems do?
Anchor the plant in the soil, absorb water and minerals, store material produced in the shoot for later use
Plants use __, __, and __ ___ to absorb materials and move them over __ distances.
Diffusion, osmosis, active transport, short
What is only moved by diffusion over short distances?
O2 and CO2
What is only used to move water, sugar, and nutrients over long distances?
bulk transport
What do diffusion, osmosis, and bulk transport move?
water, minerals, and sugar into and out of cells
How do cells maintain equilibrium?
Molecules move from higher to lower concentration - down a concentration gradient
What is the definition of osmosis?
diffusion of water across a semi-permeable membrane (a membrane that prevents movement of non-water molecules)
What does the movement of water depend on?
Concentrations of the non-water molecule called solutes
Does water move into areas with more or fewer solutes?
More solutes, there is less water there and they are maintaining equilibrium
What does it mean to move against the concentration gradient?
Areas of lower concentration to higher
What is active transport?
Materials moving against the concentration gradient, concentrating materials in cells
Does active transport require energy?
yes
what is osmotic pressure or solute potential?
The osmotic pull on water across a membrane by hypertonic solutions
What is a hypertonic solution?
any external solution that has a high solute concentration and low water concentration
What happens when there is more hypertonic in a solution?
The greater the pull on water it will have
What does it mean when we say pure water has no osmotic pull?
It’s always hypotonic to other solutions
True or false: cells are made of pure water
False, they contain some solutes
What does a cells osmotic pull depend on?
Their solute concentration compared to the solution outside their membrane.
How can osmotic pulling pressure of a plant cell be counteracted?
Turgor pressure
What is turgor pressure?
A pushing pressure of the cells contents against the cell wall
What helps a cell keep upright?
Cell turgor pressure
What happens when a plant has low turgor pressure?
It wilts
Does water always move? How?
Water always moves by osmosis into and out of cells
How do organisms cause water to move and out of them?
organisms can manipulate the solute concentration of their cells
What is active transport?
Energy generated by the cell
What mechanism do organisms use to manipulate their solute concentration?
Active transport
Where does energy come from and how is it produced?
Energy comes from ATP produced by cellular respiration
What do guard cells do?
Regulate gas exchange and limit water loss
How many guard cells surround the central pore?
2
The guard cells can __ or __, changing the size of the __ and ___ or ___ the stoma
The guard cells can shrink or swell, changing the size of the pore and opening or closing the stoma
What mechanism do guard cells use to open stoma?
Active transport