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Biology Dictionary for GCSE Biology and A Level Biology

 

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

H

Habitat: The physical or abiotic part of an ecosystem, i.e. a defined area with specific characteristics where the organisms live, e.g. oak forest, deep sea, sand dune, rocky shore, moorland, hedgerow, garden pond, etc.

Haemoglobin: A vital protein found in red blood cells, consisting of 4 polypeptide chains with a haem group on each unit. One oxygen molecule will bind to each Haem group for oxygen carriage in the blood. Key function – to pick up oxygen where abundant (lungs), and release it where needed (tissues).

 

Haemophilia: Sex linked genetic disease, faulty allele prevents blood clotting. 

 

Haploid: A cell/organism which contains a single set of chromosomes e.g. eggs & sperm. Shown as n e.g. n = 23 in humans

 

Herbicide: Chemical which inhibits growth of, or kills, plants (weeds).

 

Heterozygous: Possessing two different alleles of a particular gene. Written as Aa or Bb etc

 

Hierarchy: In taxonomy, a layered system of groups within groups, with no overlap.

 

Homologous chromosomes: A pair of chromosomes that have the same genes in the same places (loci) although not always the same alleles. Human have 23 homologous pairs

 

Homozygous: Possessing two alleles the same e.g. AA or aa. Said to be “true breeding”

 

Huntington’s disease: Genetic disease caused by dominant allele that makes a brain-degenerating protein. Does not begin until age 35-40, often after gene has been passed on

 

Hydrostatic Pressure: the pressure of fluid within a vessel, e.g.: blood in an artery has high hydrostatic pressure. Created by the ventricles.

As I write the biology dictionary and make the videos to help you learn the definitions by listening in addition to reading them, you'll get the added benefit of hearing and learning the correct pronunciation of biological terminology - but there's more! I'm also making some interactive revision flashcards too! So you can revisit the key words when revising and really embed those a level biology definitions in your head! - The flashcards will be like this (See image below and click to download).

A-Level Biology is a whole lot easier when you know the definitions of commonly used words. This biology dictionary is here to help you learn those A level biology definitions. Remember, a good command of biological terminology (at GCSE but especially at A level) can mean the difference between a poor grade and an excellent one! Since of course you get marks awarded for using the correct biological definitions in the right context when answering exam questions and writing up lab work, coursework and assignments.

The biology dictionary is mainly aimed at a level biology students since at a level, the amount of new technical language expect is quite a lot!

 

Make learning biology definitions a regular part of your studies and keep checking in as more keywords and gcse biology definitions and a level biology definitions are added.

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*Note this A-Level biology Dictionary / Glossary of key terms is not comprehensive and will be updated and added to regularly, so keep checking in and make learning and revising a level biology definitions a consistent part of your biology studies

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