Totipotent Cells A?stem cell?is a cell that can?divide?(by mitosis) an?unlimited number of times Each new cell that is produced when a stem cell divides has the potential to?remain a stem cell?or t...
Gene Mutations A?gene mutation?is a change in the sequence of base pairs in a DNA molecule that may result in an altered polypeptide Mutations occur?continuously?and?spontaneously Errors in the DNA...
The Definition of a Community Species?do not exist by themselves in their own isolated environment, they interact with other species forming?communities A community can be defined as: Multiple popu...
Genetic Variation Phenotype variation The observable characteristics of an organism are its phenotype Phenotypic variation is the?difference in phenotypes?between organisms of the same?speci...
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?...
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...
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 ...
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...
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...
