Structure and Functions of Living Organisms Flashcards
What gas do plants need to take in for aerobic respiration?
Oxygen (O2)
What gas to plants need to remove from respiration?
Carbon dioxide (CO2)
What gas do plants need to take in for photosynthesis?
Carbon dioxide (CO2)
What gas do plants need to remove from photosynthesis?
Oxygen (O2)
What gas do plants need to remove from photosynthesis?
Oxygen (O2)
Give 3 adaptations of leaf tissue for gas exchange
- Stomata (pores) allow diffusion of gases in and out of the plant
- Thin to shorten the diffusion distance
- Air spaces in the spongy mesophyll layer allow gases to diffuse
Why don’t plants keep the stomata open permanently?
Plants need to close the stomata to reduce water loss
Draw a graph to show how photosynthesis and respiration are affected by light intensity
Why do plants release more CO2 compared to O2 at night?
- Respiration continues during the night whereas photosynthesis does not
- Respiration releases CO2 and photosynthesis releases O2
Describe the general structure of the lungs
- Trachea branches into two bronchi
- Bronchi branch into bronchioles
- Bronchioles carry air to the alveoli
Describe the structure of an alveolus
- Small sacs with capillaries around them
- Contain a surfactant so walls don’t stick together and so gases can dissolve to help diffusion
What is the purpose of the pleural membrane?
The pleural membrane covers the lungs, reduces friction and keeps the lungs moist
What are the intercostal muscles?
They are a group of muscles found between the ribs that are involved in breathing by changing the size of the thorax
How do the diaphragm and intercostal muscles work together during expiration (breathing out)?
Expiration:
- Diaphragm relaxes and moves up
- External intercostal muscles relax
- Volume in the thorax decreases and air moves out
How do the diaphragm and intercostal muscles work together during inspiration (breathing in)?
Inspiration:
- Diaphragm contracts and moves down
- External intercostal muscles contract
- Volume in the thorax increases and air moves in
Give 3 health issues caused by smoking
- Cancer
- Bronchitis
- Coronary heart disease
How does smoker’s cough arise?
- Cilia on cells lining the trachea waft mucus containing dirt out of the lungs
- Smoking can kill cells lining the trachea
- A build-up of mucus in the lungs can cause people to develop smoker’s cough
What is the definition of
Diffusion?
The spreading out of particles from an area of higher concentration to an area of lower concentration.
What is the definition of Osmosis?
The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane.
The larger the surface area of the membrane, does the diffusion rate get faster or slower?
Faster
What is the definition of Active Transport?
The movement of substances from more dilute solution to a more concentrated soltion (against the concentration gradient) using energy from respiration.
What is the definition of Cellular Respiration?
The process by which cells break down nutrients like Glucose etc into useable energy
What is the photosynthesis equation?
Carbon dioxide + water → Glucose + oxygen
6CO2 + 6H2O →
C6H12O6 + 6O2.
What is definition of phtosynthesis?
the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar.