Biological Definitions


Flashcards on Biological Definitions, created by Yamminnnn on 10/01/2015.
Flashcards by Yamminnnn, updated more than 1 year ago
Created by Yamminnnn over 8 years ago

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Question Answer
Genotype The genes responsible for a persons traits.
Phenotype The physical expression of a trait. These can be affected by the environment. For example, height could be affected if someone has a poor diet whilst growing up.
Interspecific Variation Variation which arises between different species. For example, mammals are unable to breath underwater, but fish can.
Intraspecific Variation Variations which occur between individuals of the same species. For example in the canine family there are different sized dogs, and different builds.
Mutations Changes which occur in an individual due to chromosomes and genes. For example, ginger hair is a mutation.
Pathogen An organism which can cause disease.
Infection This occurs when a pathogen enters the tissue of an organism and colonises.
Gas-exchange system The process by which air is inhaled into the lungs and oxygen is diffused into the blood stream, and carbon dioxide is diffused out and then exhaled out of the body.
Genes Sections of DNA on one chromosome which code for one or more polypeptide.
Tumour These are produced when cells divide uncontrollably, and cause large swellings in the body.
Enzymes Chemicals which can break down large molecules and control most chemical reactions.
Aerobic Respiration Respiration which includes oxygen as well as glucose and releases energy, h20 and carbon dioxide.
Respiration Occurs in all living organisms, and within humans is the intake of oxygen and the expulsion of carbon dioxide.
Nucleus Controls a cells activities and contains the hereditary material for the cell.
Cell Membrane Usually a semi permeable membrane which controls the substances which are able to leave or enter a cell.
Mitochondria Made up of cristae and a matrix, and are the sites of respiration. They are therefore responsible for producing ATP, which can be used as energy to transport proteins into or out of a cell.
Ribosomes Important in protein synthesis, and contain RNA.
Cell wall A membrane around plant cells mostly which are made of cellulose, and can strengthen a cell.
Root hair cells Cells with hair like extensions which can be used to increase the surface area and increase rates of absorption. E.g: plants absorbing water or minerals.
White Blood Cells Main cells involved in the immune system. Can engulf and destroy invading pathogens.
Microvilli Finger-like projections off of an epithelial cell. Can be used to allow more efficient absorption due to increased surface area.
Rough Endoplasmic Reticulum Rough ER contains ribosome's on its surface, and provides a large surface area for the synthesis of protein and also a pathway for materials such as proteins across a cell.
Smooth Endoplasmic Reticulum Synthesise, store and transport lipids and carbohydrates.
Golgi Apparatus In eukaryotic cells. Modifies proteins and can transport them in vesicles which pinch off from the main body of the organelle.
Lysosome Contain enzymes such as proteases and lipases, and can break down material ingested by a cell or worn out organelles.
Red Blood Cells Do not contain a nucleus, and packed with haemoglobin in order to absorb oxygen.
Osmosis The net movement of water molecules through a semi-permanent membrane from a high to low gradient.
Diffusion A net movement of particles from a high to low gradient.
Chromosomes A thread-like structure of nucleic acids and protein found in the cells of most organisms. Contains genetic information.
Alleles Different forms or variations of genes.
DNA Two strands of nucleotides made of a sugar, a phosphate group and an organic base coiled in a double helix fashion.
Species Organisms that can breed fertile offspring.
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