Biology Reference
In-Depth Information
Parasitoid.
A parasitic arthropod in which the larva develops within the
body of the host.
Parthenogenesis.
Reproduction in which offspring are produced from
unfertilized spores, seeds, or eggs.
Pelagic zone.
The open water region of an aquatic ecosystem.
Phenolic glycosides.
Organic compounds that consist of a phenol ring
with an attached sugar residue.
Phenology.
The seasonal pattern of growth and reproduction of an
organism.
Phenotype.
The realized expression or outward appearance of a partic-
ular genetic makeup.
Pheromone.
A volatile organic substance produced by individuals that
induces particular behavioral responses in other individuals of the species.
Photoperiod.
The length of daylight at a particular time of year.
Phytophagous.
Feeding on plant material.
Piscivore.
An animal feeding on fish in an aquatic ecosystem.
Planktivore.
An animal feeding on minute plants or animals in the open
water of an aquatic ecosystem.
Pleiotropy.
The influence of a gene on different characteristics of an
organism.
Polyphagy.
Feeding on a wide variety of food types.
Polygenic.
Referring to a characteristic influenced by more than one
gene.
Polymorphism.
The existence of different alleles for a particular gene,
or the frequency of genes with more than a single allele.
Polyploidy.
The increase in the number of sets of chromosomes in indi-
viduals of one species, a process termed autopolyploidy, or an increase in
the number of chromosome sets in individuals produced by interspecific
hybridization, a process termed allopolyploidy. The number of sets of
chromosomes is often indicated by a prefix, e.g., tetra- (4), sexta- (6),
octo- (8).
Red Queen Hypothesis.
Hypothesis that predators or parasites and
their prey or hosts engage in an evolutionary contest to improve their
respective abilities for exploitation or defense.
