nutrients and gas requirments Flashcards
what is an autotroph
is an organism that can make its own food e.g. plants
outline the root systems
transpiration stream: plants obtain water through branching networks of fine roots and root hairs, water is absorbed from the soil via root hairs of plants, water then travels from the roots to all parts of the plant through xylem
what is the purpose of plants having finer and finer roots
this results in a large surface area to volume ratio, increasing absorption of nutrients
what is the transpiration stream
a process that draws the water up the stem and helps pull more water from the soil into the plant
what is xylem
carries water and mineral ions in one direction (roots to leaves)
what is the stems role in the shoot system
the stem provides structural support and a transport pathway between the roots and leaves
what is vascular tissues and where is it found
found in the stem, they are groups of tubes conduction material comprised of phloem (sucrose), xylem (water), and cambium
what is cambium
area of cell division, where new xylem and phloem are formed
In plants have a vascular system, describe how water (CATT) is moved throughout the plant.
C= cohesion (water molecules are attracted to each other, sticking together)
A= adhesion (when the water sticks to the sides of the tube)
T= tension caused in the lead by the water lost during transpiration causes water to move up and replace lost water
T= transpiration (water is pulled up the xylem cells, by the evaporative pull of transpiration)
draw the structure of a leaf
look at notes
describe the function of waxy cuticle in a leaf structure
a waxy cuticle minimises water loss from the leaf (reflect sunlight → not too much absorption)
describe the function of palisade cells in a leaf structure
palisade cells containing many chloroplasts are lined up vertically near the upper surface of the leaf to absorb sunlight they are at the top to increase photosynthesis
describe the function of spongy mesophyll in a leaf structure
spongy mesophyll cells are loosely and irregularly organised to all easy movement of gases through the leaf (help with gas exchange)
describe the function of transport tissue in a leaf structure
transport tissue in the leaf is organised into vein. This provides support as well as a pathway for the movement of water and the products of photosynthesis (vascular bundle)
describe the function of guard cells in a leaf structure
guard cells, which are often more numerous on the underside of the leaf, change shape to open and close ‘pores’ known as stomata
describe the function of stomata in a leaf structure
the gases oxygen and carbon dioxide are exchanged between the inside and outside of the leaf through stomata. if in a dry environment, stomata is closed to preserve water for photosynthesis
In plants have a vascular system, describe how glucose (translocation) is moved throughout the plant.
sugars (glucose and sucrose) are made by photosynthesis in the source (leaf). the transported to phloem by active transport, sugars move to the next phloem cell through the sieve and reach the sink (their destination) to then undergo respiration
what is phloem comprised of
sieve cells joined end to end to form a series of connecting tube
sieve plate joins each sieve cell -> no cell wall at plate just membrane
the major metabolic functions are carried out by companion cell next to sieve cell
what is phloem
transport sugars (glucose and sucrose), amino acids and hormones in any direction around the plant
how does an MRI determine plant structure
Magnetic resonance imaging (MRI) is a medical imaging technique that uses a magnetic field and computer generated ration waves to create detailed 3D images of organs (leaf) and tissues
how does an PET determine plant structure
Positron emission tomography (PET) scan is an imaging test that uses a special dye containing radioactive tracers
how does an x-ray computed micrograph determine plant structure
A sample of plant tissue positioned in and x-ray beam is rotated and hundreds of images are recorded and converted into a 3D image
where is gas exchange in a leaf
stomates are the sight of gas exchange in a leaf, carbon dioxide enters the stomates and oxygen leaves the leaf
what is the function of alveoli in mammals
most important part of the respiratory system, their function is to exchange oxygen and carbon dioxide gas molecules to and from the bloodstream
