Biology Chapter 28 Study Guide

discoba

defined by a feeding groove, allowing organisms to ingest small particles of food in their aquatic habitats by phagocytosis (phagotrophy)

List seven supergroups of protists and name a distinguishing feature for each for each that sets it apart from the others

*Discoba *Land plants and relatives *Alveolata *Stramenopila *Rhizaria *Amoebozoa *Opisthokonta

Compare and contrast the different nutritional strategies among the protists

*Phagotrophy- Heterotrophs that ingest particles *Osmotrophy- Heterotrophs that rely on uptake of small organic molecules. *Photoautotrophy- Photosynthetic *Moxotrophy- Able to use autotrophy and phagotrophy or osmotrophy depending on conditions

discoba

A biologist discovers a new unicellular organism that possesses multiple flagella, a pronounced feeding groove, and two small, but equal-sized, nuclei. The organism has reduced mitochondria (mitosomes), no chloroplasts, and is anaerobic. To which clade does this organism probably belong.

paramecium

A ciliated (it propels itself via cilia) protist that lives in fresh water and eats other tiny organisms for food.

Outline different methods of plastid acquisition

Classified within several eukaryotic supergroups that each display distinct features. Phagocytosis food particles are collected within the feeding groove, they are then taken into cells by a type of endocytosis. Endosymbiosis which is when smaller species lives within the body of a larger species known as the host.

Describe how protists can be distinguished by their ecological roles, habitats, and motility

Ecological Role: *Algae- Generally photoautotrophic *Protozoa- Heterotrophic (Don't carry out photosynthesis, have to eat something) *Fungus-like- Resemble fungi in body form and absorptive nutrition Habitat: *Particularly common and diverse in oceans, lakes, wetlands, and rivers *Plankton: Swimming or floating protist -phytoplankton: Photosynthetic -protozoan plankton: Heterotrophic *Perphyton (Plant-like) -Attached by mucilage to underwater surfaces Motility: *Flagella-swim *Cilia- Swim (Shorter and more abundant than flagella) *Amoeboid movement- Using pseudopodia *Gliding on protein or carbohydrate slime

Define endosymbiosis and explain how it relates to the evolution of protists

Endosymbiosis- A symbiotic relationship in which the smaller species- the symbiont- lives inside the larger species. Endosymbiosis theory- A theory that mitochondria and chloroplasts originated from bacteria that took up residence within a primordial eukaryotic cell.

Describe the life cycle of the parasitic, Plasmodium falciparum, and explain its importance to world health

Enters the bloodstream as a life stage known as a sporozoite, which reach the liver and enter into liver cells. After several cycles of cell division, a life stage known as merozoite develops and is released from liver cells. Merozoites have protein complexes at their front ends, or apices, that allow them to invade human blood cells. they consume the hemoglobin in red blood cells. While living within red blood cells, they form rings, which can be visualized by staining and the use of a microscope, allowing diagnosis. The Merozoites reproduce asexually, generating large numbers of new ones that synchronously break out of red blood cells at intervals of 48 to 72 hours.

protist reproduction

Most reproduce asexually, some reproduce sexually

land plants and relatives

Obtained plastids by primary endosymbiosis(have an envelope with 2 membranes) phyla chlorophyta, rhodophyta, and cryptophyta

rhodophyta

Phylum of large, multicellular marine algae whose pigments are especially efficient in absorbing the green, violet, and blue light that penetrates into the deepest ocean waters.

Characterize the various reproductive strategies employed by protists

Protist populations grow by means of asexual reproduction involving mitosis, and many persist through unfavorable conditions as tough-walled cysts.

amoebazoa

Protists: this group lacks a cell wall, traps its food by engulfing it and includes the plasmodial slime molds. Move by means of pseudopodia, reproduce by binary fission and engulf food.

rhizaria

Several groups of flagellates and amoebae that have thin, hairlike extension of their cytoplasm-known as filose pseudopodia- are classified into the Supergroup rhizaria.

List the three main means of locomotion used y protists

Some can move by cytoplasmic streaming using pseudopodia, like an amoeba, others use cilia or flagella to propel themselves. Cilia are short, numerous hair like structures that beat in a rhythm to move the animal along. A flagella is a long, whip like tail that the animal uses. The amoeba "oozes" from place to place.

opisthokonta

The eukaryan clade that contains both fungi and animalia, choanoflagellates have posterior flagella that propel cells like sperm or chytrid spores (in other protists, flagella are anterior)

cryptophyta

The phylum _____________ includes flagellates known as cryptomonads.

Explain the need for the classification known as "supergroup" with respect to protists

They are not monophyletic

chlorophyta

group of algae is most similar to plants in terms of their cell wall composition and the type of chlorophyll they possess. Green algae