Biology - Unknown Topics Flashcards
(23 cards)
What are the main structures of a leaf?
Upper epidermis, palisade layer, spongy layer, lower epidermis
What do chloroplasts do in a leaf?
They carry out photosynthesis by absorbing light
How can you use observations from the underside of a leaf to label a diagram?
By identifying structures such as stomata and guard cells
What is photosynthesis
How plants make their food using light, carbon dioxide and water
Where does photosynthesis occur in a plant?
The leaves - in the chloroplasts
What is the equation of photosynthesis?
Carbon dioxide + water = Glucose + oxygen
What are the reactants and products of photosynthesis?
Reactants: carbon dioxide + water
Products: glucose + oxygen
How do you test for the presence of oxygen?
Use a glowing splint; if it relights in the test tube where the plant was, oxygen is present
How do you test a leaf for starch?
- Boil the leaf
- Place it in ethanol to remove chlorophyll
- Rinse
- Add iodine
If the iodine goes blue/black there is starch
What factors affect the rate of photosynthesis?
Light intensity
Carbon dioxide concentration
Temperature
What are two experiments that prove photosynthesis has taken place?
- The starch test
- The light splint experiment
What minerals are required by plants?
Nitrates, phosphates, potassium and magnesium
Why are nitrates essential for plant growth?
They make proteins and promote heathy growth
How do survival rates differ for successful adaptation?
Animals that are better adapted to their environment, are more likely to survive and reproduce
How have organisms changed over time?
By adapting - such as giraffes necks
How do you create an evolutionary sequence?
You could arrange fossils of the same animal in order of adaptations
What’s peer review?
When other people in the same field review your work
What is natural selection?
The process by which all organisms evolve
What does extinct mean?
There are no more of that species
What is biodiversity?
The variety of different species in an ecosystem
What is an endangered species?
A species at risk of becoming extinct in the near future
What is one way of protecting endangered species?
Conservation programmes such as breeding in captivity or protecting habitats.
What is one way of protecting endangered species?
By analysing graphs or tables to spot trends, increases, decreases, or changes over time.
