Misc Flashcards
Which blood vessel allows for the exchange of food and oxygen?
Capillaries
Where does photosynthesis occur?
Chloroplasts in the leaves of a plant
What is the name of the green pigment in the leaves?
Chlorophyll
What type of reaction is photosynthesis?
Endothermic
What type of energy is used in photosynthesis?
light energy
Give the word equation for photosynthesis
Carbon dioxide + water -> glucose + oxygen
Give the balanced symbol equation for photosynthesis
6CO2 + 6H2O → C6H12O6 + 6O2
Define the term limiting factor
anything that limits the rate of a reaction when it is in short supply
Give the limiting factors of photosynthesis
- temperature
- carbon dioxide concentration
- light intensity
- amount of chlorophyll
Describe how light intensity affects the rate of photosynthesis.
increasing light intensity increases the rate of photosynthesis until another factor becomes limiting
Describe how carbon dioxide concentration affects the rate of photosynthesis
increasing carbon dioxide concentration increases the rate of photosynthesis until another factor becomes limiting
Describe how temperature affects the rate of photosynthesis
increasing temperature increases the rate of photosynthesis as the reaction rate increases- at high temperatures enzymes are denatured so the rate of photosynthesis quickly decreases
Give the equation for the inverse square law for light intensity
light intensity ∝ 1
————
distance2
Why are limiting factors important in the economics of growing plants in greenhouses?
greenhouses need to produce the maximum rate of photosynthesis whilst making profit
How do plants use the glucose produced in photosynthesis?
- Respiration
- Convert it into insoluble starch for storage
- produced fat or oil for storage
- produce cellulose to strengthen cell walls
- produce amino acids for protein synthesis
Why is a leaf an organ?
there are many tissues inside the leaf that work together to perform photosynthesis
How is the upper epidermis adapted for its function?
- single layer of transparent cells allow light to pass through
- cells secrete a waxy substance that makes leaves waterproof
How is the palisade mesophyll adapted for its function?
tightly packed cells with lots of chloroplasts to absorb as much light as possible for photosynthesis
How is the spongy mesophyll adapted for its function?
air spaces increase the surface area and allow gases to diffuse quickly
What is the function of the guard cells?
control the opening and closing of the stomata
What is the function of the xylem?
transport water and mineral ions from the roots to the rest of the plant
Give three adaptations of the xylem
- made of dead cells
- no end wall between cells
- walls strengthened by a chemical called lignin to withstand the pressure of the water
What is the function of the phloem?
transport dissolved sugars from the leaves to the rest of the plant
What is the purpose of translocation?
transport dissolved sugars from the leaves to other parts of the plant for respiration, growth and storage
Define the term transpiration
movement of water from the roots to the leaves through the xylem
What is the purpose of transpiration?
- Provide water to keep cells turgid
- provide water to cells for photosynthesis
- transport mineral ions to leaves
Name four factors that affect the rate of transpiration
temperature, light intensity, humidity, and wind speed
What effect does temperature have on the rate of transpiration?
higher temperatures increase the rate of transpiration
What effect does humidity have on the rate of transpiration?
higher levels of humidity decrease the rate of transpiration
Why does increased light intensity increase the rate of transpiration?
stomata open wider to let more carbon dioxide into the leaf for photosynthesis
What is the function of the stomata?
allow diffusion of gases into and out of the plant
Where are most stomata found?
underside of leaves
What is the advantage to the plant of having a high number of stomata at this location?
reduces the amount of water loss through evaporation
How does pollution cause a decrease in biodiversity?
- It kills plants and animals
Name the level of organisation which best describes the interaction of living organisms with the non-living parts of their environment
- Ecosystem
Which term describes the community of living organisms interacting with the abiotic factors of a specific area?
- An ecosystem
Which risk factors are associated with an increased rate of non-communicable diseases?
- Lifestyle
- Alcohol
- Carcinogens
- Lack of exercise
- Smoking
- Diet
- Ionising radiation
The human body’s first line of defence against pathogens is the non-specific defence system. Describe TWO non- specific defence systems of the human body
Any TWO from:
- Skin- physical barrier
- Nose- hair/mucus trap pathogens
- Trachea/ Bronchi (cilia)/Ciliated cells wafting moving pathogens up and out of the airway
- Stomach- acidic environment kills pathogens
- Tears
- Phagocytes