You are looking at 1-20 of 1,308 entries  for:

  • Type: Subject Reference x
  • Life Sciences x
  • Science and technology x
  • Results with images only x
clear all

View:

Aardvark

Aardvark   Reference library

The Encyclopedia of Mammals (3 ed.)

Reference type:
Subject Reference
Current Version:
2007
Subject:
Science and technology, Life Sciences
Length:
1,361 words
Illustration(s):
3

Few people have had the fortune of a close encounter with the aardvark, one of Africa's most bizarre and specialized

abductor muscle

abductor muscle   Quick reference

A Dictionary of Zoology (4 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
26 words
Illustration(s):
1

A muscle that draws a structure (e.g. a limb) away from the centre line of the body. Compare adductor muscle

abscisic acid

abscisic acid   Quick reference

A Dictionary of Genetics (8 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
34 words
Illustration(s):
1

a plant hormone synthesized by chloroplasts. High levels of abscisic acid result in the abscission of leaves, flowers, and fruits.

Accentors

Accentors   Reference library

The New Encyclopedia of Birds

Reference type:
Subject Reference
Subject:
Science and technology, Life Sciences
Length:
1,093 words
Illustration(s):
2

Accentors do not have spectacular plumage, they behave unobtrusively, and most species live at high altitude and are poorly known.

accommodation

accommodation   Reference library

The Oxford Companion to the Body

Reference type:
Subject Reference
Current Version:
2003
Subject:
Science and technology, Life Sciences
Length:
800 words
Illustration(s):
1

Optical instruments (such as microscopes, cameras, and some telescopes) work by passing light through the curved surfaces of lenses, where

acetylcholine

acetylcholine   Quick reference

A Dictionary of Genetics (8 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
50 words
Illustration(s):
1

a biogenic amine that plays an important role in the transmission of nerve impulses across synapses and from nerve endings

acid

acid   Quick reference

A Dictionary of Biology (8 ed.)

Reference type:
Subject Reference
Current Version:
2019
Subject:
Science and technology, Life Sciences
Length:
113 words
Illustration(s):
2

A type of compound that contains hydrogen and dissociates in water to produce positive hydrogen ions. The reaction, for an acid HX, is commonly written:...

Acorn Worms and Allies

Acorn Worms and Allies   Reference library

The Encyclopedia of Underwater Life

Reference type:
Subject Reference
Current Version:
2007
Subject:
Science and technology, Life Sciences
Length:
1,148 words
Illustration(s):
3

Hemichordates are a minor phylum of marine invertebrates; they are not abundant and relatively few species are known. Yet they

Acquired Immune Deficiency Syndrome

Acquired Immune Deficiency Syndrome   Reference library

Encyclopedia of Evolution

Reference type:
Subject Reference
Current Version:
2005
Subject:
Science and technology, Life Sciences, Social sciences, Anthropology
Length:
6,732 words
Illustration(s):
2

This entry comprises two articles. The introductory article provides a discussion of the origins and phylogeny of HIV; the companion

acridine

acridine   Quick reference

A Dictionary of Biology (8 ed.)

Reference type:
Subject Reference
Current Version:
2019
Subject:
Science and technology, Life Sciences
Length:
33 words
Illustration(s):
1
A chemical (see formula) that is capable of causing *frameshift mutations in the DNA sequence. Several derivatives of acridine (such as acridine orange) are used as dyes or biological ... More
acridine dyes

acridine dyes   Quick reference

A Dictionary of Genetics (8 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
39 words
Illustration(s):
1

heterocyclic compounds that include acridine (shown below) and its derivatives. These molecules bind to double-stranded DNAs as intercalating agents. Examples

acridine orange

acridine orange   Quick reference

A Dictionary of Genetics (8 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
15 words
Illustration(s):
1

an acridine dye that functions both as a fluorochrome and a mutagen (q.v.).

acriflavin

acriflavin   Quick reference

A Dictionary of Genetics (8 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
13 words
Illustration(s):
1

an acridine dye that produces reading frame shifts. See mutagen, frameshift mutation.

acrocentric

acrocentric   Quick reference

A Dictionary of Plant Sciences (4 ed.)

Reference type:
Subject Reference
Current Version:
2019
Subject:
Science and technology, Life Sciences
Length:
63 words
Illustration(s):
1

Applied to a *chromosome with a *centromere located nearer one end than the other. During the *anaphase...

actinomycin D

actinomycin D   Quick reference

A Dictionary of Genetics (8 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
20 words
Illustration(s):
1

an antibiotic produced by Streptomyces chrysomallus that prevents the transcription of messenger RNA. See RNA polymerase.

adaptive landscape

adaptive landscape   Quick reference

A Dictionary of Genetics (8 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
54 words
Illustration(s):
1

a three-dimensional graph that shows the frequencies of two genes, each present in two allelic forms (aA and bB in

adenosine phosphate

adenosine phosphate   Quick reference

A Dictionary of Genetics (8 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
115 words
Illustration(s):
1

any of three compounds in which the nucleoside adenosine is attached through its ribose group to one, two, or three

adrenaline

adrenaline   Quick reference

A Dictionary of Biology (8 ed.)

Reference type:
Subject Reference
Current Version:
2019
Subject:
Science and technology, Life Sciences
Length:
139 words
Illustration(s):
1

A hormone (see formula), produced by the medulla of the *adrenal glands, that increases heart rate and *blood pressure...

aerobic respiration

aerobic respiration   Quick reference

A Dictionary of Biology (8 ed.)

Reference type:
Subject Reference
Current Version:
2019
Subject:
Science and technology, Life Sciences
Length:
122 words
Illustration(s):
1
A type of cellular *respiration in which food is completely oxidized to carbon dioxide and water, with the release of chemical energy, in a process requiring atmospheric oxygen. The oxygen ... More
affinity index

affinity index   Quick reference

A Dictionary of Ecology (5 ed.)

Reference type:
Subject Reference
Current Version:
2015
Subject:
Science and technology, Life Sciences, Social sciences, Environment
Length:
74 words
Illustration(s):
2

A measure of the relative similarity in composition of two samples. For example, A= c a+b, where ...

View: