2.2 Nutrient and Gas Requirements Flashcards
plant structure
What is a vascular system?
a network of transport system specifically for plants which allows the movement of substances around the plant
plant structure
list the main components of the vascular system
- leaf
- stem
- xylem
- phloem
- roots
plant structure
what the two main structures of the shoot system?
stem and leaves
plant structure
what does the stems do in the shoot system?
- provides both structural support and transport passagway between the roots and leaves
- at the tip their is a terminal bud which is the growing point of the plant
- internally, it contains the xylem and phloem which transports materials between the shoot and root system
plant structure
what does the leaves do in the shoot system?
- absorbs the sunlight for photosynthesis
- site of transpiration, aiding the movement of water from the roots to the leaves
plant structure
describe the function of the root system
- anchors the plant and abosrbs water/inorganic material from the soil
- very long for it to reach the water underground
- covered by fine hair roots increasing the surface area to absorb water
- water enters through osmosis
plant structure
explain in detail what the xylem is.
- made up of long tubular cells to join and make pipes
- forms the vascular system of gymnosperms (no flowers) and angiosperms (has flowers)
- only moves UPWARDS - one direction only
- uses passive transport
- has lignin, which is a major component of wood. it keeps the system open, even once it’s dead
- the lignin within the xylem provides the stem a firm and rigid structure
- uses the tension-cohesion theory
plant structure
explain in detail what the phloem is.
- transports more concentrated nutrients (e.g. sugars)
- formed by long, rigid columns
- at the bottom they have sieve plates which helps move material e.g. suagrs, amino acids, hormones through
- uses the source to sink theory
- moves things both up and down
plant structure
how was the movement of products in photosynthesis traced?
a radioactive tracer was used to show that sunlight acts upon the chlorophyll to begin the process of manufacturing organic compounds
* radioisotopes are forms of an element that emit radiation. this was used as a tracer to follow the pathway of molecules in photosynthesis
plant structure
who were the scientists who led to discovery of photosynthesis through their theories?
- Jan Baptista Val Helmont (1580- 1644)
- Joseph Preiestly (1733 - 1804)
- Jan Ingenhousz (1730 - 1799)
Plant Structure
What is the transpiration-cohesion-tension theory?
- the theory to how water moves up the xylem
the evidence includes: - the stems shrinkly very slightly
- water continues to move through the xylem even when the roots have been cut off
- plants which has been chilled/poisoned to remove all living cells continue to conduct water -> this rules out active transport as it’s not using energy to conduct this
Gas Exchange
What are the main parts of the leaf cross section?
- waxy cuticle and epidermis (reduces evaporation and prevent foreign material from entering e.g. bacteria)
- palisade and spongey mesophyll (contains the chloroplasts)
- stomates (found on the botton, each containing a guard cell
Mammalian Digestive System
What is the difference between physical and chemical digestion?
Physical digestion involves the manual process of breaking down food while chemical digestion involves enzymes and other chemicals in the body breaking it down into small molecules.
Mammalian Digestive System
List the main parts of the digestive system (both physical and chemical)
- Mouth (teeth to the esophagus)
- Stomach
- Small intestine (duodenum, jejunum, ileum)
- Large intestine (colon)
Mammalian Digestive System
Explain what occurs in the physical digestion of food.
starts with the teeth, specifically the molars which chews the food into smaller particles, increasing the surface area and making it easier to go down the esophagus.
