Alternation of Generations

A life cycle in which there is both a multicellular diploid form, the sporophyte, and a multicellular haploid forma, the gametophyte; characteristic of plants and some algae.

Blade

1. A leaflike structure of a seaweed that provides most of the surface area for photosynthesis.
2. The flattened portion of a typical leaf.

Conjugation

1. In prokaryotes, the direct transfer of DNA between two cells that are temporarily joined.
When the 2 cells are members of different species, conjugation results in horizontal gene transfer.
2. In ciliates, a sexual process in which two cells exchange haploid micronuclei but do not respond.

Dinoflagellate

Member of group of mostly unicellular photosynthetic algae with two flagella situated in perpendicular groves in cellulose plated covering the cell.

Diplomonad

A protist that has modified mitochondria, two equal-sized nuclei, and multiple flagella.

Euglenid

A protist, such as Euglena or its relatives, characterized by an anterior pocket from which one or two flagella emerge.

Euglenozoan

Member of a diverse clade of flagellated protists that includes predatory heterotrophs, photosynthetic autographs, and pathogenic parasites.

Excavata

One of the 5 supergroups of eukaryotes proposed in a current hypothesis of the evolutionary history of eukaryotes. Excavates have unique cytoskeletal features, and some species have an "excavated" feeding groove on one side of the cell body.

Foram (Foraminiferan)

An aquatic protist that secretes a hardened shell containing Calcium Carbonate and extends pseudopodia through pores in the shell.

Golden Algae

A biflagellated, photo synthetics protist named for its cool, which results from its yellow and brown carotenoids.

Green Algae

A photo synthetics protists names for green chloroplasts that are similar in structure and pigment composition to those of land plants. Green algae are a paraphyletic group, some of whose members are more closely related to land plants than they are to other algae.

Heteromorphic

Referring to a condition in the life cycle of plants and certain algae in which the sporophyte and gametophyte generation differ in morphology.

Holdfast

A rootlike structure that anchors a seaweed.

Isomorphic

Referring to alternating generations in plants and certain algae in which the sporophytes and gametophytes look alike, although they differ in chromosome number.

Kinetoplastid

A protists, such as a trypanosome, that has a single large mitochondrion that houses and organized mass of DNA.

Mixotroph

An organism that is capable of both photosynthesis and heterotrophy.

Opisthokont

Member of diverse clase Opisthokonta organisms that descended from am ancestor with a posterior flagellum, including fungi, animals, and certain protists.

Pseudopodium

A cellular extension of amoeboid cells used in moving and feeding.

Radiolarian

A protist, usually marine, with a shell generally made of silica and pseudopodia that radiate from the central body.

Red Algae

A photosynthetic protists, names for its color, which results from a red pigment that masks the green of chlorophyll. Most red algae are multicellular and marine.

Rhizaria

One of the 5 supergroups of Eukaryotes proposed in a current hypothesis of the evolutionary history of eukaryotes; a morphologically diverse protists clade that is defined by DNA similarities.

Secondary Symbiosis

A process in eukaryotic evolution in which a heterotrophic eukaryotic cell engulfed a photosynthetic eukaryotic cell, which survived in a symbiotic relationship inside the heterotrophic cell.

Stipe

A stemlike structure of a seaweed.

Stramenophile

A protist in which a “hairy” flagellum (one covered with fine, hairlike projections) is paired with a shorter, smooth flagellum.

Thallus

The study of energy transformations that occur in a collection of matter.

Unikonta

One of five supergroups of eukaryotes proposed in a current hypothesis of the evolutionary history of eukaryotes. This clade, which is supported by studies of myosin proteins and DNA, consists of amoebozoans and opisthokonts. See also Excavata, Chromalveolata, Rhizaria, and Archaeplastida.