Biology 4, 5, 6 Questions Flashcards
What do A C G and T stand for?
Adenine, Cytosine, Guanine and Thymine
Who were the first two scientists who worked out the structure of DNA?
Watson and Crick
How do plants use glucose to make protein?
Glucose is combined with nitrate ions from the soil to make amino acids, which are made into proteins
Why are insoluble substances (like starch)used for storage in plants?
- They don’t affect water concentration in cells
- They dissolve in water, so they cant move away from storage areas in solution.
What is the definition of ENVIRONMENT?
All the conditions that surround a living organism
What is the definition of HABITAT?
The place where an organism lives
What is the definition of POPULATION?
All the members of a single species that live in a habitat.
What is the definition of COMMUNITY?
All the populations of different organisms that live together in a habitat
What is the definition of ECOSYSTEM?
A community and the habitat in which it lives
How do you estimate population size?
Number in 1st sample x number in 2nd sample / number in 2nd sample previously marked
What other substances can glucose be used for or stored for?
- For respiration to release energy
- Stored in seeds and turned into lipids
- Making proteins for growth and repair
- Turned to cellulose for making cell walls
- Stored as starch when photosynthesis is not happening (at night)
What did Priestley’s experiments show?
Plants restore something to the air that burning and breathing take out. This substance is oxygen.
What did Van Helmont’s experiments show?
The tree must have gained mass from another source. Plants also gain mass using CO2 from the air and not just from taking in minerals from the soil.
What three limiting factors control the rate of photosynthesis?
Light intensity, carbon dioxide levels and temperature
What is diffusion and where does it happen?
The net movement of particles from an area of high concentrations to an area of low.
This happens in liquids and gases.
What does the rate of diffusion depend on?
The distance, the concentration of the particles and the surface area.
What are the 6 different ways of preserving food?
Canning, Cooling, Freezing, Drying, Adding Salt and Sugar and Adding Vinegar
What is Hydroponics?
Growing plants in mineral solutions without the need for soil
What is Biological Control?
The use of living organisms to control pests
What is transpiration?
The loss of water from a plant caused by evaporation and diffusion in the leaves.
What are the benefits of the transpiration system?
- It keeps the plant cool
- The plant has a constant supply of water for photosynthesis
- Water creates turgor pressure in the plant cells, which give it support and stops it from wilting.
What is Xylem?
They take water and minerals from the roots up the shoot to the leaves in the transpiration stream.
What is a Phloem tube?
They transport food substances up and down the stem to growing and supporting tissues.
What is osmosis?
The net movement of water particles across a semi permeable membrane from a region of high concentration to a low.
What four minerals do plants need?
Nitrates (for making amino acids and proteins for cell growth), Phosphates (for respiration and growth), Potassium (for photosynthesis and respiration) and Magnesium ( for making chlorophyll)