B4: It's a Green World Flashcards
Learn all about Plant Things!
What is a Pooter?
A simple technique in which gathering insects is easy and doesn’t cause any harm.
They are good for finding out which species are present but you have to be systematic about your sampling in order to get representative results and it is difficult to get ideas of numbers.
What are Sweepnets?
Sweepnets are used in long grass or moderately dense woodland where there are lots of shrubs.
It is difficult to get truly representative samples, particularly in terms of relative numbers of organisms.
What are Pitfall Traps?
Pitfall traps are set into the ground and used to catch small insects, e.g. beetles. Sometimes, water or ethanol are placed at the bottom of the hole to kill the insects. This prevents them from escaping.
This method can give an indication of relative numbers of organisms in a given area if enough are used to give a representative sample.
What are Quadrats?
Quadrats are square frames that typically have sides of length 0.5m. They provide excellent results as long as they are places randomly. The population of a certain species can then be estimated.
Example:
If an average of 4 dandelion plants are found in each 0.25m square quadrat, a scientist would estimate that 16 dandelion plants would be found in each 1m squared, and 16,000 dandelion plants in a 1000m square field.
What is the formula for working out the estimate of the total population size in a habitat?
Population Size = No. in first sample (all marked) x No. in second sample (marked and unmarked) divided by No. in second sample which were previously marked.
Example: If 56 mice are caught in woodland and a small section of fur is removed from their tail with clippers. The mice are released. The next evening, a further sample of 62 mice are caught. 25 of these mice have shaved tails. What is the total population size?
Answer:
Population Size = 52 x 62 divided by 25 = 139 Mice
What is a population?
A population is the number of individuals of a species in a defined area.
What is a community?
A community is a total number of individuals of all the different populations of organisms that live together in a habitat at any one time.
What is biodiversity?
Biodiversity is the variety of different species living in a habitat.
What is an ecosystem?
An ecosystem is a physical environment with a particular set of conditions, plus all the organisms that live in it.
The organisms interact through competition and predation. They are affected by the physical factors present in the ecosystem, e.g. soil type, light intensity.
Some ecosystems, such as Ocean depths, are still unexplored, with possible undiscovered species.
What is the scientific name for making food using energy from the Sun?
Green plants do not absorb food from the soil. They make their own using sunlight. This is called Photosynthesis (‘making through light’).
Word and Symbol equations for photosynthesis:
Word:
Carbon Dioxide + Water –Light Chlorophyll–> Glucose + Oxygen
Symbol: 6CO2 + 6H2O –Light Chlorophyll–> C6H12O6 + 6O2
Why do plants convert glucose into starch?
Because starch is an insoluble carbohydrate, which can be stored in cells.
Why do plants convert glucose into cellulose?
It is need for the cell walls. It is very similar to the structure of starch, but the long chains are cross-linked to form a meshwork.
