Mod 2 - Organisation of Living Things Flashcards
What is breathing?
mechanical process of organs working together
what is the action of respiring?
The molecular process to exchange CO2 for O2
Explain the process of transpiration in plants.
- process of moving fluid through xylem vessels to transport water and minerals from root to leaves
- initial absorption at the roots
- capillary action within the xylem vessels
- evaporation to the leaf.
Describe the function of plant roots.
The roots of plants absorb water and minerals through the initial active transport
describe what root pressure is.
- force that helps to drive fluids upwards into the xylem
- pressure moves from high water potential to low water potential with the water moving into the roots via osmosis.
what are some factors that affect plant transpiration
- light
- water availability
- temperature
- wind and humidity
- potassium ion concentration
explain the pressure-flow theory
- explain how movement of sap in a plant is from source to sink
- sugars begin at the source and is pumped into the phloem tube cells
- through osmosis, water is moved into cells causing a rise in pressure which eventually moves the sap (sugar molecules)
How do heterotrophs obtain energy?
heterotrophs obtain compounds by consuming other organisms/products
What occurs during photosynthesis
- Plants harvest light energy from the Sun and convert it into chemical energy via photosynthesis
- Photosynthesis is an endothermic reaction and undergo process of carbon fixation
- Photosynthesis occurs in the chloroplast
- In vascular plants chloroplasts are located in the mesophyll cells in the leaves and in the stem
- In non-vascular plants chloroplasts are in the leaves.
6CO2 + 6H2O → C6H12O6 + 6O2
Explain the gas exchange within humans.
- internal in order to keep the membrane moist and minimise water loss
- the alveoli, located in the lungs is the membrane responsible for gaseous exchange
- air travels from the nose or mouth to the trachea, which divides into the bronchi, moving the air to the lungs.
- The bronchi further divides into bronchioles with each bronchiole ending in clusters of tiny air sacs called alveoli.
- Oxygen diffuses into the bloodstream from the alveoli to be transported to all cells of the body.
Describe an open circulatory system?
- Insects possess an open circulatory system
- consists of a heart, lacks blood vessels and haemolymph (equivalent to blood) which is pumped by the heart or movement
describe a closed circulatory system
e.g. Vertebrates such as fish, birds and mammals possess a closed circulatory system
- consist of a heart that pumps blood around the body in sealed blood vessels
- Pulmonary circulation transports deoxygenated blood between the heart and lungs
- systematic circulation moves oxygenated blood from the heart to the rest of the body.
Describe the functions and properties of a heart.
- the heart pumps blood around the body and is made up of cardiac muscle, connective tissues and nerves
- consists of 2 sides with the right side pumping deoxygenating blood into lungs to receive oxygen and the left side pumping oxygenating blood from lungs to the rest of the body.
- 4 chambers; left atrium, right atrium, left ventricle and right ventricle.
transport in the phloem
- phloem are living cells joined end to end that transport sugar (sucrose) and amino acids around the plant via a process called translocation
- occurs from the source to the sink
e.g. sugar is transported from the leaves (source) to the roots (sink)
explain the transpiration-cohesion-tension theory
the transpiration-cohesion-tension theory is used to explain the movement of water and dissolved ion minerals in plants.
1) Firstly, water and ions from the soil diffuse into the root hairs through osmosis
2) the water and mineral ions move up the stem to the leaves in the xylem due to upward transpiration pull (tension).
therefore unidirectional movement of water and mineral ions in xylem due to capillary action of narrow xylem tubes, cohesion of water molecules and adhesion between water and xylem wall.
