Biology Key Terms: Cloning, Genetics, Evolution & Classification

adult cell cloning

The production of a new animal from the cell of another adult animal.

agriculture

Relating to farming: cultivating soil, growing crops and rearing livestock.

Alfred Russel Wallace

A scientist who independently proposed the theory of evolution by natural selection. He published joint writings with Darwin in 1858.

allele

A different form of a gene.

amino acid

A monomer that is a building block for proteins.

antibiotic resistance

Changes in the DNA of bacteria, or the acquisition of genes from other bacteria, that make it resistant to antibiotics.

antibiotic resistant bacteria

Strains of bacteria that are no longer killed by specific antibiotics.

antibiotic

A drug that helps to cure bacterial disease by killing infective bacteria inside the body.

archaea

Primitive bacteria usually living in extreme environments.

artificial selection

See selective breeding.

asexual reproduction

Reproduction involving only one parent that produces genetically identical offspring (clones).

bacteria

Microscopic single-celled organisms. They may produce toxins that damage tissues and make us feel ill.

base

One of four different chemicals (A, C, G, T) that make up part of a nucleotide in DNA.

binomial system

A system of naming living things by their genus and species.

bulb division

A type of asexual reproduction where a new bulb separates from the old one and from which a new plant will grow.

Carl Linnaeus

The scientist who developed the system used for classifying living things into groups depending on their structure and characteristics.

Carl Woese

The scientist who used chemical analysis to develop the three-domain classification system.

cell

The basic building block of all living things.

cell division

The process by which a parent cell divides into two or more daughter cells.

Charles Darwin

A scientist who published his theory of evolution by natural selection in the book On the Origin of Species in 1859.

chromosome

A long molecule of DNA found in the nucleus of a cell, which carries genes.

classification

The arrangement of living things into groups according to their similarities.

clone

An organism or cell produced asexually from one parent, to which they are genetically identical.

cloning

The process of making an identical copy of a parent organism.

coding DNA

A section of DNA that codes for a protein.

collagen

The main structural protein found in skin.

complementary strands

Two strands of DNA that contain sequences of nucleotide bases that will pair with one another.

crop

A plant that is grown on a large scale commercially.

cutting

A piece of plant that is cut from a parent plant and then made to form roots and shoots by putting it in favourable conditions.

cystic fibrosis

An inherited disorder of cell membranes that is caused by a recessive allele.

diabetes

A disease that occurs when a person's blood glucose levels are too high.

differentiation

The process of an undifferentiated cell becoming adapted to carry out a specific function.

disease resistance

The ability to prevent or reduce disease in otherwise susceptible organisms.

DNA

Deoxyribonucleic acid, the genetic material contained in chromosomes.

domesticated

A tame animal kept as a pet or on a farm.

dominant allele

An allele that is always expressed, even if only one copy is present.

double helix

A description of the structure of a DNA molecule which consists of two strands that twist around each other.

economic

Relating to trade, industry and money.

embryo

An unborn or unhatched offspring in the early stages of development.

embryo screening

A procedure to test if embryos carry the gene for certain genetic diseases.

embryo transplant

The splitting apart of cells from a developing animal embryo before they become specialised.

enzyme

A biological catalyst that speeds up the rate of a reaction.

ethical

Relating to morals, right and wrong.

eukaryota

The domain that includes protists, fungi, plants and animals.

evidence

The available information or facts that either support or counter a scientific theory or hypothesis.

evolution

A change in the inherited characteristics of a population over time through a process of natural selection.

evolutionary tree

A visual representation of evolution.

extinction

When there are no remaining individuals of a species still alive.

family tree

A diagram showing the relationship between people in several generations of a family.

fertile

Capable of producing offspring.

fertilisation

The fusion of male and female gametes.

fossil

The 'remains' of an organism from millions of years ago, which are found in rocks.

fusion

The process of joining two things together.

gamete

Sex cell; sperm and egg cells in mammals and pollen and egg cells in flowering plants.

gene

A small section of DNA on a chromosome that codes for a particular sequence of amino acids, to make a specific protein.

gene expression

The appearance in a phenotype of a characteristic or effect attributed to a particular gene.

gene theory

The idea that genes are the basic units in which characteristics are passed from one generation to the next.

genetic cross

The purposeful mating of two individuals to combine genetic information in the offspring.

genetic engineering

The process of taking genes from one species and introducing them into the genome of another species.

genetic material

Material that is responsible for inheritance (DNA and RNA).

genetic modification

The process of altering the DNA of an organism.

genetically modified (GM) crop

A plant that has been modified to include DNA from a different organism and is grown on a large scale commercially.

genome

The entire genetic material of an organism.

genotype

The alleles present in an organism.

geological activity

The movement of tectonic plates beneath the Earth's surface.

geology

The study of the physical structure of the Earth and the processes that act on them.

Gregor Mendel

A scientist who carried out breeding experiments on plants in the mid-19th century. He observed that the inheritance of each characteristic is determined by 'units' that are passed on to descendants unchanged.

heterozygous

A genotype that has two different alleles, one dominant and one recessive.

homozygous

A genotype that has two of the same alleles. Either two dominant alleles or two recessive alleles.

immune system

The organs and processes of the body that provide defence against infection and toxins.

inbreeding

The mating of individuals that are closely related genetically, which can result in some breeds being particularly prone to disease or inherited defects.

inheritance

The process by which genetic information is passed from parent to offspring.

inherited disorder

A disease caused by faulty genes.

insulin

A hormone that is produced by the pancreas when the blood glucose concentration is too high.

interbreed

The mating of individuals with an individual of another species.

Jean-Baptiste Lamarck

A scientist who theorised that changes which occur in an organism during its lifetime can be inherited. We now know that in the vast majority of cases this type of inheritance cannot occur.

Linnaean system

The system used for classifying living things into groups depending on their structure and characteristics. The groups are kingdom, phylum, class, order, family, genus and species.

malarial parasite

A protist that reproduces asexually in the human host, but sexually in the mosquito.

meiosis

A type of cell division that produces four genetically different gametes.

migration

The seasonal movement of a population from one region to another.

mitosis

A type of cell division that produces two identical daughter cells.

MRSA

A strain of bacteria that is resistant to antibiotics.

mutation

A change in a gene or chromosome.

natural selection

The theory of evolution that states all species of living things have evolved from simple life forms that first developed more than three billion years ago.

non-coding DNA

A section of DNA that does not code for proteins. Can be involved in turning genes on or off.

nucleotide

The basic unit of DNA, consisting of a sugar, a phosphate group and one of four bases (A, C, G or T).

nucleus

A sub-cellular structure that contains genetic material and controls the activities of the cell.

offspring

The children or young of an organism.

On the Origin of Species

The book that Darwin published in 1859 that included his theory of evolution by natural selection.

phenotype

The characteristic expressed as a result of the combination of alleles.

phosphate group

A molecule with the chemical formula PO4 3-. It is one part of a nucleotide.

plasmid

A small ring of DNA that codes for specific features, such as antibiotic resistance.

polydactyly

An inherited disorder caused by a dominant allele that results in a person being born with extra fingers or toes.

polymer

A large molecule that consists of many repeating units.

population

All the members of a single species that live in a habitat.

protein

A molecule made up of long chains of amino acids, used for building the cells and tissues of the body.

protein synthesis

The process of making protein molecules from amino acids using the genetic code from DNA.

Punnett square

A genetic diagram showing the possible allele combinations resulting from a genetic cross.

recessive allele

An allele which is only expressed if the individual has two copies and does not have the dominant allele of that gene.

reproduction

The production of offspring.