Symbiosis/ symbiotic relationship
is close and often long-term interaction between two or more different biological species
any relationship between individuals of different species where both individuals benefit
a relationship between two living organisms where one benefits and the other is not significantly harmed
one member of the association benefits while the other is harmed
Alternation of Generations
Sexual reproduction involves the two alternating processes of meiosis and fertilization.
Offspring does not resemble parent.
happens to cnidarians
Complex Life Cycle
Parasites that must infect more than one host species to complete their life cycles
mode of reproduction by which offspring arise from a single parent, and inherit the genes of that parent
only; it is reproduction which does not involve meiosis, ploidy reduction, or fertilization. The offspring will
be exact genetic copies of the parent.
process that creates a new organism by combining the genetic material of two organisms
form of asexual reproduction where growth and development of embryos occur without fertilization
in which the male pierces the female's abdomen with his penis and injects his sperm through the wound
into her abdominal cavity (hemocoel)
a phenotypic difference between males and females of the same species
state of strobilar development characterized by the possession of gonads of only one sex (male or female)
characterized by the presence of both male and female reproductive organs in the same organism (not
necessarily at the same time) Dioecious
characterised by a species having distinct male and female organisms
have separate male and female flowers on the same organism
animals that lay eggs, with little or no other embryonic development within the mother
mode of embryonic development, in which the embryo, without any protective envelope, develops in utero
within the parental organism
cellular process of engulfing solid particles by the cell membrane
cell directs the contents of secretory vesicles out of the cell membrane and into the extracellular space
animals that feed by straining suspended matter and food particles from water, typically by passing the
water over a specialized filtering structure.
predator (an organism that is hunting) feeds on its prey (the organism that is attacked)
feeding on autotrophs
Radial Symmetry (pie)
An organism with radial symmetry exhibits no left or right sides. They have a top and a bottom (dorsal
and ventral surface) only.
Biradial Symmetry - Ctenophora body components of an animal are arranged such that similar parts are located to either side of a central
axis and each of the four sides of the body is identical to the opposite side but different from the adjacent
only one plane, called the sagittal plane, will divide an organism into roughly mirror image halves
is a multinucleate cell which can result from multiple cell fusions of uninuclear cells
pressure of the fluid and action of the surrounding circular and longitudinal muscles are used to change
an organism's shape and produce movement, such as burrowing or swimming
is a fluid-filled cavity formed within the mesoderm of some animals
Meiofauna are small benthic invertebrates that live in both marine and freshwater environments
creatures can live in an empty space or gap between spaces full of structure or matter.