Chapter 11 Protists Protista Protists Some are too

Chapter 11 Protists

Protista (Protists) Some are too tiny to be seen without a microscope while others are meters long Some are like animals, plants or fungi

General Characteristics All are eukaryotic, have nuclei Most are single celled but some are multi cellular Scientists believe more complex organisms originated from protists

Protists Producers- get food through photosynthesis Consumers- get food from other sources Grouped by how they get food into 3 groups

Funguslike Protists Get food from dead organic matter Secrete juices into the food source and absorb the digested nutrients Reproduce like fungus

Slime Mold Thin masses of living matter Colorful, shapeless globs of slime Live as single celled organisms, but congregate in times of stress

Slime molds Live in cool, shady moist places in the woods and fresh water Eat bacteria, yeast, small bits of decaying plants and animal matter

Unfavorable Conditions Slime molds develop stalklike structures with rounded knobs at the top (spores) The spores can survive a long time without nutrients until conditions improve

Water Molds Most are small and single celled Live in water, moist soil or other organisms Decomposers or parasites Caused the Great Potato Famine

Plantlike Protists Producers Algae (alga) have chlorophyll (pigment for photosynthesis) and other pigments Almost all live in water

Seaweed or Kelp Multicellular algae Live near the shore Can grow to be meters in length

Phytoplankton Single celled algae Usually float near the surface Produce most of the world’s oxygen Divided into phyla based on color and cell structure

Algin and Carageenan 2 substances extracted from algae used in many foods Including ice cream , salad dressing, jelly beans and instant pudding

Volvox An example specimen of green algae Single celled but live in colonies You will see in lab

Diatoms Single celled, unusual shapes Found in salt and fresh water Contain silica (a glass-like substance) and cellulose Used in tooth paste and silver polish

Dinoflagellates Single celled, live primarily in salt water, Have 2 flagella, whip-like strand used for movement Some are red and produce a poison which can cause red tides If fish eat enough of the poison, they can be toxic to humans

Euglenoids Single celled, live in fresh water, characteristics of plants and animals Use photosynthesis and consume food Have one flagella (whip-like tail) and contractile vacuoles

Animal-like Protists Protozoa Grouped into 4 categories Amoebalike protists Flagellates Cilliates Spore forming protists

Amoebalike protists Soft jelly-like, contractile vacuoles Move with psuedopodia (false feet) Feed by engulfing food Include Foraminiferans and Radiolarians (amoeba like with shells)

Flagellates Flagella for movement Parasites Giardia lamblia found in water, affects hikers when drinking untreated water Another lives in the guts of termites to help them digest the cellulose in wood

Cilliates Most complex protozoans Covered in tiny hair-like projections called cillia used for movement and feeding Best known is Paramecium

Spore-Forming Protists Parasites, no cillia or flagella present so they can’t move on their own Have complicated life cycles Malaria caused by Plasmodia vivax

Reproduction of Protists Asexual – one parent Fission- dividing of parent into 2 organisms Euglena and Amoeba Sexual – 2 parents Conjugation – swap DNA and then divide Paramecium