Protists

Question 1

What is a colonial organism? (2)

Answer 1

A colonial organism is a collection of unicellular organisms living together. Individual cells of a colonial organism can survive on their own.

Question 2

What is a multicellular organism?

Answer 2

Multicellular organisms consist of individual cells that, if separated from the organism, could not survive on their own.

Question 3

Protists are the earliest and simplest form of _____.

Answer 3

Protists are the earliest and simplest form of eukaryotes.

Question 4

Are all protists unicellular?

Answer 4

Most protists are unicellular but some form colonies (colonial organism) and some are simple multicellular organisms.

Question 5

What do most protists have at one point in their life cycles?

Answer 5

Most have flagella or cilia at one point in their life cycle.

Question 6

Protists are found anywhere there is _____.

Answer 6

Protists are found anywhere there is water. Even temporary bodies of water such as puddles.

Question 7

Protists are categorized based on what?

Answer 7

Protists are categorized based on how they obtain nutrients.

Question 8

What are the three types of protists?

Answer 8

Animal-like, plant-like & fungal-like.

Question 9

Describe protozoa. (3)

Answer 9

Animal-like protists are called protozoa. These are chemoheterotrophs that obtain food by ingestion (phagocytosis). Some live in fresh water, some in marine (salt water) and some in soil habitats.

Question 10

What are paramecia?

Answer 10

Paramecia are protozoa and are part of a group called ciliates because they have cilia. They use this cilia to move and feed. They contain an oral groove (cilia move food into it) and live in fresh water. They reproduce asexually and have 2 types of nuclei: one large macronucleus for everyday functions and 1 or more small micronuclei for the exchange of genetic material between organisms.

Question 11

What are amoeba?

Answer 11

Amoeba are protozoa and are rhizopods (because they make pseudopodia). They move and feed using pseudopodia (phagocytosis), the cellular extensions formed using microfilaments. They live in fresh water, marine and soil habitats. They reproduce asexually and have no flagellated stages in their life cycles.

Question 12

Describe algae.

Answer 12

Plant-like protists are called algae. They contain chloroplasts for photosynthesis and have cell walls made of cellulose. There are two types of green algae; Chlorophyta and Charophyta (Charophyta are the ancestor of land plants).

Question 13

Give an example of a unicellular plant-like protists. (3)

Answer 13

Chlamydomonas are unicellular plant-like protists. They have 2 flagella. They reproduce either sexually or asexually.

Question 14

Give an example of of a multicellular plant-like protist.

Answer 14

Ulva, also known as sea lettuce is a multicellular plant-like protist.

Question 15

Give an example of a colonial plant-like protist. (2)

Answer 15

Volvox is a colonial plant-like protist. They have a division of labour within the colony.

Question 16

What are diatoms? (3)

Answer 16

Diatoms are a specific type of algae. They are photosynthetic plankton (phytoplankton) that contain chloroplasts. They are unicellular but some can form colonies. They are different in that they have a cell wall made of silica, a glass-like substance.

Question 17

Describe fungal-like protists. (2)

Answer 17

Many fungal-like protists are saprophytic (they are decomposers). They are absorptive chemoheterotrophs, meaning they secrete enzymes that digest organic material and then absorb the nutrients.

Question 18

Give an example of a fungal-like protist.

Answer 18

Water mold is a fungal-like protist, they decompose dead animals in water.

Question 19

What is the ecological role of protists?

Answer 19

Protists play many ecological roles. There are plant-like protists that are primary producers. Animal like protists are consumers. Fungal-like protists behave as decomposers, taking dead organic carbon and transforming it into inorganic material for producers to use.