AQA A Level Biology復(fù)習(xí)筆記7.2.1 Populations
Species Exist in Populations A?species?can be defined as a group of?similar organisms?that can?reproduce?to give?fertile offspring Organisms of the same species have the?same number of chromosomes?...
AQA A Level Biology復(fù)習(xí)筆記7.1.1 Key Terms in Genetics
Key Terms in Genetics Genes & alleles The DNA contained within chromosomes is essential for cell survival Every?chromosome?consists of a long DNA molecule which?codes for several differe...
AQA A Level Biology復(fù)習(xí)筆記6.4.1 Principles of Homeostasis
Homeostasis In order to?function?properly and?efficiently, organisms have different?control systems?that ensure their?internal conditions?are kept relatively?constant Physiological control systems ...
AQA A Level Biology復(fù)習(xí)筆記6.3.1 Muscle Pairs
Muscle Pairs The?effective movement?of the human body requires both?muscle?and an?incompressible skeleton This is because muscles will only produce effective movement if they?pull on a structure?th...
AQA A Level Biology復(fù)習(xí)筆記6.2.1 Neurones
Myelinated Motor Neurones Information is sent through the nervous system as?nerve impulses?– electrical signals that pass along nerve cells known as?neurones A bundle of neurones is known as a nerv...
AQA A Level Biology復(fù)習(xí)筆記6.1.1 Survival & Response
Responding to Change Aids Survival Organisms must respond to changes in their environment in order to survive They can only survive if they are successful at: Finding favourable conditions for livi...
AQA A Level Biology復(fù)習(xí)筆記5.4.1 Nutrient Cycles
Nutrient Cycles Living organisms require?nutrients?from their?environments?for?growth?and other processes (e.g. reproduction) These nutrients are then?returned?to the environment when organisms pro...
AQA A Level Biology復(fù)習(xí)筆記5.3.1 Primary Producers
Plants are Primary Producers An?ecosystem?in a?particular area?includes: All the?living?components (i.e.?biotic factors?such as organisms and their interactions) All the?non-living?components (i.e....
AQA A Level Biology復(fù)習(xí)筆記5.2.1 Mitochondria & the Need for Energy
Structure & Function of the Mitochondria Mitochondria are rod-shaped organelles 0.5 - 1.0 μm in diameter They are the site of aerobic respiration in eukaryotic cells The function of mitochondri...
