F' (F-prime) factor: Normally, the F factor contains
genes related to conjugation/mating. The F' factor contains an additional
portion of the bacterial genome. F Factor (Fertility Factor): Transmissible plasmid
(episome) in bacteria (such as E. coli) that acts as a sex factor. It
is a circular DNA about 94 kb long. Conjugation and chromosomal gene
transfer occur from F+ (male) to F- (female) bacterium. F- strain: E.coli strain behaving as recipients during
conjugation (female). It lacks the F factor. F+ strain: E.coli strain behaving as donors during
conjugation (male). It has the F factor. F0.1: The fishing mortality rate at which the increase
in yield per recruit in weight for an increase in a unit of effort is
only 10 percent of the yield per recruit produced by the first unit
of effort on the unexploited stock (i.e., the slope of the yield-per-recruit
curve for the F0.1 rate is only one-tenth the slope of the curve at
its origin). F1: First filial (son or daughter) hybrids arising
from a first cross. Subsequent generations are denoted by F2, F3 etc. Fauna: A certain species of animals occurring in a
particular region or period. Fecundity: The potential of an organism to produce
offspring (measured as a number of gametes). Fertilization: The joining or fusion of the male gamete
(sperm) and the female gamete (egg) to form a zygote during sexual reproduction.
See also gamete, zygote. Filament: chain of living cells Filamentous growth: A pattern of growth resulting in
a branched or unbranched structure of cells joined end to end. Filter feeder: Any organism that filters small animals,
plants, and detritus from water or fine sediments for food. Organs used
for filtering include gills in clams and oysters, baleen in whales,
and specialized appendages in crustaceans and marine worms. Fingerprinting: The use of RFLPs or repeat sequence
DNA to establish a unique individual-specific pattern of DNA fragments. Fisher’s Fundamental Theorem: The rate of increase
in fitness is equal to the additive genetic variance in fitness. This
means that if there is a lot of variation in the population the value
of S will be large. Fisher's Theorem of the Sex Ratio: In a population
where individuals mate at random, the rarity of either sex will automatically
set up selection pressure favoring production of the rarer sex. Once
the rare sex is favored, the sex ratio gradually moves back toward equality. Fishing Effort: 1. The total fishing gear in use for
a specified period of time. When two or more kinds of gear are used,
they must be adjusted to some standard type. 2. Effective fishing effort. Fishing Intensity: 1. Effective fishing effort. 2.
Fishing effort per unit area 3. Effectiveness of fishing. Fishing Mortality: Deaths in a fish stock caused by
fishing. Fishing Power: The catch which a particular gear or
vessel takes from a given density of fish during a certain time interval.
For example, larger vessels (horsepower) have a greater ability to catch
more fish, thus the greater their fishing power. Also, improvements
in a vessel or gear, such as fish finders, Loran, etc., can increase
fishing power. Fitness: Lifetime reproductive success of an individual
(i.e., the total number of offspring who themselves survive to reproduce).
It can be seen as the extent to which an individual successfully passes
on its genes to the next generation. It has two components: survival
(viability) and reproductive success (fecundity). Variation in fitness
is the major driving force in biological evolution. Five-prime (5') end: The end of a DNA or RNA strand
with a free 5' phosphate group corresponding to the transcription initiation
(see also three-prime end). Fixed: The establishment of a single allelic variant
at a locus as a result random genetic drift.
flagellar pore - In desmokont dinoflagellates, the pore in which flagella
emerge located in the periflagellar area (flagellar pore area). Flagellate: Refers to cells that have motility organelles
or microorganisms that possess one or more flagellum used for locomotion. Flagellum: Whip-like structures arising from the cell
and responsible for propelling cells in a watery fluid: All dinoflagellates
at some time in their life cycle have two dissimilar flagella: a transverse
flagellum (provides propulsion) and a longitudinal flagellum (provides
direction). They either emerge through one pore or two separate pores.
Flora: All of the plant species in a specified region. Flower: The part of an angiosperm containing the organs
of reproduction (male stamen and female stigma as well as the ovary). Fluorescence: Emission of energy as visible light.
Fmax: The rate of fishing mortality for a given exploitation
pattern rate of growth and natural mortality, that results in the maximum
level of yield per recruit. This is the point that defines growth overfishing. Food Chain: A linear sequence of organisms that exist
on successive trophic levels within a natural community, through which
energy is transferred by feeding. Primary producers capture energy from
the environment (through photo- or chemo-synthesis) and form the base
of the food chain. Energy is then passed to primary consumers (herbivores)
and on to secondary and tertiary consumers (carnivores and top carnivores)
(e.g. phytoplankton -> zooplankton -> herring -> salmon ->
killer whales). Once they die, these organisms are in turn consumed
and their energy transferred to detrivores and decomposers. Compare
food web. Food web: The feeding relationships of several to many
species within a community in a given area during a particular time
period. Two broad types are recognized: (1) grazing webs involving producers
(e.g., algae), herbivores (e.g., copepods), and various combinations
of carnivores and omnivores; and, (2) detritus webs involving scavengers,
detritivores, and decomposers that feed on the dead remains or organisms
from the grazing webs, as well as on their own dead. A food chain refers
to organisms on different trophic levels, while a food web refers to
a network of interconnected food chains. Footprinting, DNAase: DNA with protein bound is resistant
to digestion by DNAase. When a sequencing reaction is performed using
such DNA, a protected area representing the footprint of the bound protein
will be detected. This permits identification of the protein binding
regions of the DNA.
Foramen: A relatively large comma-shaped cavity (apical pore)
on the Po plate of Alexandrium spp. (sometimes fishhook shaped as in
Alexandrium catenella and A. tamarense). It is a diagnostic feature
of the APC. Fouling: Occurs when large numbers of plants or animals
attach and grow on various structures (floats, pipes, and pilings),
often interfering with their use. Fouling organisms include barnacles,
mussels, bryozoans, and sponges. Founder effect (Sewall Wright effect): A type of genetic
drift in which allele frequencies are altered in a small population
which is a nonrandom sample of a larger (main) population.
Frameshift mutations: Mutations, usually deletions or insertions,
that change the reading frame of the codon triplets. Fresh water: Water that has a salt concentration of
0.0-0.5l. Fruit: Mature ovary with seeds inside. Its function
is seed protection and dispersal. Fruits are a development of the ovary
wall and sometimes the other flower parts as well. Its formation is
induced by the plant hormone auxin which is released by the maturing
seeds.
Fu/HC: The fusion/histocompatibility system of the Ascidians.
It is involved in self - nonself recognition regulating the fusion between
compatible organisms and prevention of self-fertilization. Link to an
abstract on Fu/HC research (see also Bottryllus and protochordates). Fugu: The puffer fish, Fugu rubripes, has essentially
the same number of genes as the human genome, but its genome is eight
times more compact than human genome (about 400 Mb as opposed to 3 Gb).
A project to sequence the whole Fugu genome is underway. Link to Fugu
Website which has the draft sequence (Oct 25, 2001). Fungus: A Kingdom made up of a diverse group of unicellular
or multicellular, eukaryotic organisms which are not plants or animals.
Many are parasitic or saprophytic. Both asexual and sexual reproductions
are possible. The Kingdom includes five phyla: Zygomycetes (conjugating
fungi, black bread molds), Deuteromycetes (reproduce only asexually,
Aspergillus 'brown mold' and Penicillium), Basidiomycetes (incl. mushrooms),
Ascomycetes (incl. Neurospora 'bread mold' and Saccharomyces 'baker's
yeast') and Mycophycophyta (incl. lichens). Some of them (Basidiomycetes)
have one of the most ancient pheromone-based mating-type recognition
systems. See Fungi in Kimball's Biology Pages and Fungus in Tree of
Life. See also dikaryosis, heterokaryon and mating types.