Unit 3- Life On Earth Flashcards
What is an organism’s ecological niche?
An organism’s ecological niche is its role it plays in an ecosystem.
What are the stages of speciation?
Isolation Mutation Natural selection Different gene pools Speciation
What is an isolation barrier?
An isolation barrier divides a population into two or more sub-populations. It acts as a barrier to gene flow.
What organisms turn proteins into ammonium by using decomposition?
Decomposers- soil bacteria and fungi.
What is the difference between interspecific and intraspecific competition?
Interspecific competition is between different species.
Intraspecific competition is between the same species.
What is meant by the term invertebrate?
An organism without a backbone.
What is the difference between abiotic and biotic factors?
Abiotic- Non-living factor.
Biotic- Living factor.
What is a mutation?
A random change in the sequence of DNA.
How much energy is passed on at each stage in a food chain?
10%
Define biodiversity.
The variety of living things in an ecosystem.
What is a species?
A species is a group of animals that can breed to produce fertile offspring.
What is the purpose of a producer in a food chain?
Producers can make their own food and are vital to provide energy for the consumers.
What is evolution?
Evolution is the scientific explanation for the biodiversity that has arisen over 3.5 billion years.
Name 3 isolation barriers.
Geographical barrier
Reproduction barrier
Ecological barrier
What do the arrows in a food chain show?
The arrows in a food chain shows the direction of energy flow.
Name 3 abiotic factors.
Soil moisture, temperature and pH.
Name three ways that 90% of energy is lost between each stage in a food chain.
Heat
Movement and
Undigested material
Are mutations always negative?
Mutations can be positive, negative or neutral.
What can be used to count numbers of plants?
Quadrat.
What are pitfall traps used for?
Pitfall traps are used sample the small invertebrates living on the ground.
Name the two types of mutation that can arise.
Gene mutation
Chromosome mutation.
Name 4 biotic factors.
Predation
Competition
Disease
Grazing
Name three TYPES of consumer and what food type they eat.
Herbivore- plants
Carnivore- Animals
Omnivores- plants and animals
Define Biomes.
Biomes are areas of the planet that shares similar flora and fauna.
State three adaptations of a predator.
Eyes to the front of the head.
Fast runner
Sharp teeth/ claws
State the term used to describe an increased rate of mutation and name examples of ways to increase the rate of mutation.
Mutagenic agent.
Mustard gas or radiation.
State examples of sampling technique.
Netting, pitfall traps, tree beating, quadrat.
What is a producer?
A producer is a green plant which produces it’s own food.
What rules should always be considered when using a quadrat?
Ensure its thrown randomly.
Ensure its thrown multiple times.
What precautions should be considered whilst using pitfall traps.
Set trap at ground level.
Have a lid to protect from rain/predators
Holes at the bottom for drainage
Empty the trap regularly
What is grazing?
Grazing is a biotic factor, if an area is undergrazed the biodiversity decreases. Overgrazing also reduces biodiversity.
What is predation?
Predation is when one organism hunts another and can affect many species in an ecosystem.
What is the difference between predator and prey?
Predator- animal that hunts others
Prey- animal being hunted.
Define adaptation.
An inherited characteristic that makes an organism better suited to a changing environment.
