The phase in the cell cycle when DNA replication occurs
Interphase

The part of the peripheral nervous system that controls involuntary actions
Autonomic system

A plant hormone that causes leaves to fall off trees in autumn
Abscisic acid

Measurement of the total amount of carbon dioxide emissions of an individual per year
Carbon footprint

The division of the cytoplasm through the constriction of the cell membrane at the end of cell division
Cytokinesis

The structure in the amniotic egg that stores wastes
Allantois

The inner lining of the uterus where implantation of the embryo occurs
Endometrium

Part of the female reproductive system where fertilisation occurs
Fallopian tube/oviduct

The organelle in the cytoplasm which is the site of protein synthesis
Ribosome

The name of the bond that forms between amino acids in a protein molecule
Peptide

The process by which a DNA molecule makes identical copies of itself
Replication

The name of the process when homologous chromosome pairs fail to separate during meiosis
Non-disjunction

The permanent disappearance of a species from earth
Extinction

A testable statement that may be accepted or rejected
Hypothesis

The type of nucleic acid that carries a specific amino acid
tRNA/transfer RNA

A type of fertilisation in which the nucleus of a sperm fuses with the nucleus of an ovum outside the body of the female
External fertilisation

The growth of part of a plant in response to gravity
Geotropism/gravitropism

The condition of the blood vessels in the skin in humans when the environmental temperature is low
Vasoconstriction

The reproductive strategy when hatchlings are able to move and feed themselves
Precocial

The sensory receptors found in the semicircular canals
Cristae

The type of pollution that occurs when hot fluids are released into rivers and oceans
Thermal pollution

A layer inside the eye that absorbs light, thus reducing reflection
Choroid

A genetic cross involving two different characteristics
Dihybrid

The variety of life forms that exist on Earth
Biodiversity

The opening in the skull through which the spinal cord enters
Foramen magnum

A group of organisms of the same species living in the same habitat at the same time
Population

A testable statement that can be accepted or rejected
Hypothesis

A genetic disorder resulting in the non-production of the clotting factor in blood
Haemophilia

Total disappearance of a species from Earth
Extinction

A segment of a chromosome that codes for a particular characteristic
Gene

The ability of an organism to walk on two limbs
Bipedalism

A type of reproduction in humans where the foetus develops inside the uterus
Vivipary/Viviparous

Structures found only in animal cells that form the spindle during cell division
Centrioles/Centrosome

The movement of part of a plant in response to gravity
Geotropism/Gravitropism

The amount of carbon dioxide produced by an individual per unit time as a result of his/her activities
Carbon footprint

The stage in humans when sexual maturity is reached in males and females
Puberty

A change in the internal or external environment that will be detected by a receptor and converted into an impulse
Stimulus

Small tubes placed in the tympanic membrane to drain liquid from the middle ear
Grommets

Part of the human ear that directs sound waves into the auditory cana
Pinna

The type of inheritance where the dominant allele masks the expression of the recessive allele in the heterozygous condition
Complete dominance

The process by which genetically identical organisms are formed using biotechnology
Cloning

A group of organisms of the same species in a specific habitat
Population

The type of vision shared by apes and humans that allows fordepth perception
Stereoscopic/Binocular

The family to which humans belong
Hominidae/Hominids

A human disorder caused by non-disjunction of chromosome pair 21
Down syndrome/ trisomy 21

The stage of protein synthesis during which mRNA forms from DNA
Transcription

Structures in different organisms that have a similar basic plan which suggests that they share a common ancestor
Homologous

The position of a gene on a chromosome
Locus

The type of variation in a population with no intermediate phenotypes
Discontinuous variatio

The part of the brain that controls the heart rate
Medulla oblongata

The maintenance of a constant internal environment in the body within certain limits
Homeostasis

The plant growth hormone that promotes seed dormancy
Abscisic acid/ABA

A collective name for the membranes that protect the brain
Meninges

A hormone that regulates the salt concentration in human blood
Aldosterone

A layer in the atmosphere that is damaged by chlorofluorocarbons (CFCs)
Ozone/O3

A hormone that stimulates the maturation of sperm
Testosterone/FSH/LH

Chromosomes that carry the same set of genes
Homologous/homologues/bivalent

Two or more alternative forms of a gene at the same locus
Alleles/Multiple alleles

The structure responsible for pulling chromosomes to the poles of an animal cell during cell division
Spindle fibres/spindle threads/spindle apparatus

A phase in the cell cycle that occurs before cell division
Interphase

A diagrammatic representation showing possible evolutionary relationships among different species
Phylogenetic tree/cladogram

The type of vision shared by apes and humans that allows for depth perception
Binocular/stereoscopic

A genetic cross involving two characteristics
Dihybridcross

A genetic disorder characterised by the absence of a blood-clotting factor
Haemophilia

The present-day distribution of organisms
Biogeography

The structure in the ear that equalises the pressure on either side of the eardrum
Eustachian tube

Measurement of the total amount of carbon dioxide emissions of an individual, a defined population or a company per year
Carbon footprint

The type of pollution caused when water is released into a river after being heated in power stations or industries
Thermalpollution

The watery fluid that supports the cornea and the front chamber of the eye
Aqueous humour

The hormone produced by the Graafian follicle
Oestrogen

The hormone responsible for the formation of the corpus luteum
Luteinising hormone/LH

The receptors in the ear that detect changes in the direction and speed of any movement of the body
Cristae

A hormone which stimulates the secretion of thyroxin
TSH/Thyroid-stimulating hormone

The type of fertilisation associated with viviparous reproduction
Internal fertilisation

The series of changes that take place in the shape of the lens and the eyeball in response to the distance of an object from the eye
Accommodation

Similar structures on different organisms that suggest they have a common ancestor
Homologous

The complete set of chromosomes in the cell of an organism
Genome

A bar code pattern formed from DNA
DNA profile/fingerprint

The condition that results from the absence of skin pigmentation
Albinism

The bonds formed between amino acids
Peptide bonds

A representation of the number, shape and arrangement of all the chromosomes in the nucleus of a somatic cell
Karyotype /Karyogram

Openings in the nuclear membrane that allow mRNA to leave the nucleus
Nuclear pores

A copy of an organism that is genetically identical to the original organism
Clone

A tentative explanation of a phenomenon that can be tested
Hypothesis

The distribution of species in different parts of the world
Biogeography

The membranes which protect the central nervous system
Meninges

A plant growth hormone that stimulates seed germination
Gibberellin

The nervous system which consists of cranial and spinal nerves
Peripheral nervous system

A branch of the autonomic nervous system that decreases the heartbeat back to normal
Parasympatheticsystem

The outermost extra-embryonic membrane surrounding the embryo
Chorion

The hormone that regulates the salt concentration in the human body
Aldosterone

The blood vessel in the umbilical cord that carries blood rich in oxygen and nutrients
Umbilical vein

The hormone inhibited by an increased level of thyroxin
TSH /thyroid stimulating hormone

The period of development of an embryo in the uterus, between fertilisation and birth
Gestation

The structure in the head of a sperm cell that contains enzymes which break down the membrane surrounding the ovum
Acrosome

An allele that does not influence the phenotype when found in the heterozygous condition
Recessive

A section of a DNA molecule that codes for a specific characteristic
Gene

The production of a genetically identical copy of an organism using biotechnology
Cloning

The manipulation of the genetic material of an organism to get desired changes
Genetic engineering

The deliberate breeding of organisms for desirable characteristics selected by humans
Artificial selection

The explanation that species experience long periods without physical change, followed by short periods of rapid physical change
Punctuated equilibrium

The phase of meiosis during which homologous chromosomes separate and start moving towards opposite poles
Anaphase I

The defect in cell division that leads to Down syndrome
Non-disjunction

The structure that is made up of two chromatids joined by a centromere
Chromosome

An explanation for something that has been observed in nature and which can be supported by facts, laws and tested hypotheses
Theory

The period of development of an embryo in the uterus between fertilisation and birth
Gestation

Disease characterised by a lack of insulin production
Diabetes mellitus

Tube that connects the pharynx and the middle ear
Eustachian tube

A process by which nutrients become highly concentrated in a body of water, leading to increased growth of organisms such as algae
Eutrophication

A stage in the development of humans in which the embryo consists of a layer of cells surrounding a cavity
Blastocyst

The structure at the tip of a sperm cell containing enzymes and which makes contact with the egg cell during fertilisation
Acrosome

The gland in the male reproductive system of humans that produces an alkaline fluid to counteract the acid environment of the vagina
Prostate

The duct leading from the testis to the urethra in human males
Sperm duct/vas deferens

The process by which the ovum is formed through meiosis in the ovary
Oogenesis

The physical and functional expression of a gene
Phenotype

Chromosomes that are not responsible for sex determination
Autosomes

The two parts of a chromosome held together by a centromere
Chromatids

An inherited disease that affects haemoglobin and changes the shape of red blood corpuscles
Sickle-cell anaemia

The genetic make-up of an organism in respect of the alleles it possesses
Genotype

The complete disappearance of a species from Earth
Extinction

The full complement of genes present in an organism
Genome

The ability of an organism to walk on two feet
Bipedal/Bipedalism

The chromosome complement/condition of a body cell which contains two sets of chromosomes
Diploid

The point at which chromatids of homologous chromosomes cross over during meiosis
Chiasma/Chiasmata

A visual representation of an organism's chromosomes
Karyogram/Karyotype

The physical count of every individual in a population
Homeostasis

The maximum number of individuals that can be supported by an environment under prevailing conditions
Pollination

A group of populations living together in the same habitat
Asexual reproduction

The structural changes that some insects undergo before they can resemble the adult form
Reproductive isolating mechanisms

The structure in angiosperms that develops into a seed
Incomplete metamorphosis

The structure in a flower that supports the stigma
Sensory/Afferent