Biology 3 - Core Flashcards
Define species
a group of organisms that can breed together to produce fertile offspring
Define adaptation
a feature that helps an organism survive in the environment it lives in
What is a food web?
simply a number of food chains joined together
What can we learn from food chains?
how the loss of ONE organism affects the lives of MULTIPLE others - called the Independence of Living Things
Define extinction
the disappearance of a species from the earth
What happens to organisms when the environment changes?
they are likely to be less adapted to it and may struggle to survive
Which organisms are most likely to reproduce?
those that are best adapted to their environment
What are some factors that can lead to extinction?
rapid changes to the environment - such as climate etc.
new diseases
new predators
new competitors
What is one thing we learn from the fossil record?
that since the beginning of the earth, some species may have become extinct
What are the two ways in which extinction can be caused?
direct human activity
indirect human activity
What is the main importance of the sun in the survival of organisms?
they rely on the light and heat energy it produces
How is light energy used?
to drive food production
Which process leads to food production?
photosynthesis
What does photosynthesis lead to?
the production of organic compounds such as glucose - from carbon dioxide and water
Where is the light energy absorbed in a plant?
through the chemicals that make up their cells
What is energy transfer?
the energy that is carried between levels of a food chain
What percentage of energy is passed on through a food chain?
around 10%
What happens as less energy is passed on?
the number of organisms at that level get smaller
Why do all cells contain carbon?
because they all contain proteins, fats and carbohydrates
In what form is carbon passed from the atmosphere?
as carbon dioxide
What happens once co2 has been passed from the atmosphere?
it passes through organisms in complex molecules
After passing through as complex molecules, what does carbon return to the atmosphere as?
carbon dioxide
How is carbon dioxide removed from the atmosphere
by green plants through photosynthesis
What can carbon be found in when in the form of complex molecules?
fats, proteins, carbohydrates
How is carbon returned to the atmosphere?
through respiration - plants, animals, microorganisms
When an animal eats a plant, what happens to the carbon?
it becomes part of the fats and proteins in the animal
What happens to waste material from animals and plants?
it is fed on by some microorganisms and animals
What happens to the carbon dioxide from animal and plant waste?
it becomes part of the microorganisms and detritus feeders
What causes decay to speed up?
warm, moist conditions - it can be very slow in cold and dry conditions
To calculate the efficiency of an energy transfer, what equation should be used?
(energy transferred to next level / total energy in) x 100
