Protist Powerpoint
Biologist ______Date ______
Protist PowerPoint
The First Eukaryotes
Protists are ______that are not members of the plant, animal, or fungi kingdoms.
Although most protists are ______, quite a few are not.
The “Protist” Dilemma
Biologists have discovered that “protists” display a far greater degree of ______than any other eukaryotic kingdom.
______, brown algae, diatoms, and slime molds are examples of protists.
Biologists also found that many “protists” are far more closely related to members of ______eukaryotic kingdoms than they are to other “protists.”
What “Protist” Means Today
Even though the biologist building the Tree of Life prefer a ______classification, the word “protist” remains in common usage, even among scientists.
Bear in mind that “protists” are not a single kingdom but a ______of organisms that includes several distinct clades.
Protists—Ancestors and Descendants
The split between Archaea and Eukarya may have come as early as ______years ago. Since that time, protists have diversified into as many as 300,000 species.
The roots of all eukaryotic diversity, from plants to animals, are found among the ______of protists.
Amoeboid Movement
Many unicellular protists move by changing their shape, a process that makes use of cytoplasmic projections known as ______.
Amoeboid movement is powered by a cytoskeletal protein called ______. Actin also plays a role in the muscle contractions of animals.
Cilia and Flagella
Many protists move by means of cilia and flagella, structures supported by ______. ______are short and numerous, and they move somewhat like oars on a boat.
______are relatively long and usually number only one or two per cell. Some flagella spin like tiny propellers, but most produce a wavelike motion from base to tip.
Passive Movement
Some protists are ______—they depend on air or water currents and other organisms to carry them around.
These protists form reproductive cells called ______that can enter the cells of other organisms and live as parasites.
Conjugation
Paramecia and most ciliates reproduce asexually by ______cell division.
However, under stress, paramecia can remake themselves through conjugation—a process in which two organisms ______genetic material.
Paramecium has ______types of nuclei: a macronucleus and one or more smaller micronuclei.
The ______holds a “reserve copy” of every gene in the cell.
The ______has multiple copies of the genes the cell uses in its day-to-day activities.
Sexual Reproduction
Many protists have complex sexual life cycles in which they alternate between a diploid and a haploid phase, a process known as alternation of ______.
Water molds reproduce asexually by producing spores in a structure called a ______.
The male and female structures produce haploid nuclei that fuse during ______, forming a zygote that begins a new life cycle.