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.