bio ch 20

The freshwater alga Spirogyra forms long threadlike colonies called

Filaments

Stipe

Flattened stemlike structure

How are funguslike protists unlike most true fungi?

Funguslike protists have centrioles, and they also lack chitin cell walls.

Gametophyte

Gamete-producing phase, Haploid

Bladder

Gas-filled swelling

What is the largest known alga

Giant kelp

What color are the chloroplasts of chrysophytes?

Gold

Water molds produce thin filaments known as _____

Hyphae

Gullet

Indentation on one side of a ciliate into which food is swept

What is an eyespot, and what is its function?

It is a cluster of reddish pigment near the gullet end of a euglena. It helps the organism find sunlight to power photosynthesis.

What is conjugation?

It is a process that allows ciliates to exchange genetic information with other individuals.

What is a food vacuole?

It is a small cavity in the cytoplasm that temporarily stores food.

What is amoeboid movement?

It is a type of locomotion that occurs when the cytoplasm of the cell streams into a pseudopod, and the rest of the cell follows.

What is a plasmodium?

It is an aggregation of acellular slime molds that is a single structure with many nuclei.

What is a protist?

It is any organism that is not a plant, an animal, a fungus, or a prokaryote.

What causes malaria?

It is caused by the sporozoan Plasmodium.

What structure does a cellular slime mold colony produce, and what is that structure's function?

It produces a fruiting body, which produces and sends out spores.

Macronucleus

Larger nucleus containing multiple copies of most of the cell's genes

Blade

Leaflike structure

How many flagella does a zooflagellate have?

Most have either one or two flagella, though a few species have many flagella.

How do euglenas reproduce?

They reproduce asexually by means of binary fission.

The unicellular Chlamydomonas reproduces asexually by producing

Zoospores

Why are some organisms that consist of thousands of cells considered to be protists?

They are considered protists because they are so similar to others that are truly unicellular.

How are the four phyla of animal-like protists distinguished from one another?

They are distinguished by their means of movement.

Why are red algae able to live at great depths?

They are efficient in harvesting light energy.

What are algal blooms?

They are enormous masses of algae.

Where are brown algae commonly found growing?

They are found in cool, shallow coastal waters of temperate or arctic areas.

What are slime molds?

They are funguslike protists that play key roles in recycling organic material.

What are seaweeds?

They are multicellular algae.

What are cilia?

They are short hairlike projections similar to flagella.

What are pseudopods?

They are temporary projections of cytoplasm.

What pigments do brown algae contain?

They contain chlorophyll a and c, as well as a brown accessory pigment, fucoxanthin.

What pigments do red algae contain?

They contain chlorophyll a and the reddish accessory pigments called phycobilins.

What don't categories of protists based on the way they obtain food reflect about these organisms?

They don't reflect their evolutionary history.

What do cellular slime molds form when their food supply is exhausted?

They form a sluglike colony of thousands of cells.

What characteristics do green algae share with plants?

They have cellulose in their cell walls, contain chlorophyll a and b, and store food in the form of starch.

How have various groups of algae adapted to conditions of limited light?

They have evolved different forms of chlorophyll.

Why have algae been called the "grasses" of the sea?

They make up much of the base of the food chain upon which animals "graze."

"Sea lettuce" is a multicellular alga known as

Ulva

How does water affect the sunlight that passes through it?

Water absorbs much of the light's energy.

Cellular slime molds belong to the phylum

Acrasiomycota

How can an algal bloom be harmful?

A bloom can quickly deplete the water of nutrients, and cells begin to die in great numbers. The decomposition of the dead algae can rob the water of its oxygen, choking its resident fish and invertebrate life.

How do dinoflagellates obtain nutrition?

About half of dinoflagellates are photosynthetic; the other half live as heterotrophs.

Diatoms are members of the phylum ____

Bacillariophyta

Which color of light are phycobilins especially good at absorbing?

Blue

How are funguslike protists like fungi?

Both are heterotrophs that absorb nutrients from dead or decaying organic matter.

Contractile vacuole

Cavity in cytoplasm specialized to collect and pump out water

Why does the dim blue light that penetrates deep into the sea contain little energy that chlorophyll a can use?

Chlorophyll a is most efficient at capturing red and violet light.

In the process of photosynthesis, what substances trap the energy of sunlight?

Chlorophyll and the accessory pigments trap the energy of sunlight

Green algae are members of the phylum __

Chlorophyta

The yellow-green algae and the golden-brown algae are members of the phylum _____

Chrysophyta

Ciliates are members of the phylum _____

Ciliophora

Animal-like protists

Consume other organisms

Euglenophytes are members of the phylum ____

Euglenophyta .

Acellular slime molds belong to the phylum ____

Myxomycota

Fungus like protists

Obtain food by external digestion, as either decomposers or parasites

Through photosynthesis, algae produce much of Earth's

Oxygen

Brown algae are members of the phylum ___

Phaeophyta

What are phytoplankton?

Phytoplankton constitute the population of small, photosynthetic organisms found near the surface of the ocean.

Plantlike protists

Produce their own food by photosynthesis

At one time, what were all animal-like protists called?

Protozoa

Dinoflagellates are members of the phylum _____

Pyrrophyta

Anal pore

Region of cell membrane where waste- containing food vacuoles fuse

Red algae are members of the phylum _____

Rhodophyta

Sarcodines are members of the phylum _____

Sarcodina

Trichocysts

Small, bottle-shaped structures used for defense

Micronucleus

Smaller nucleus containing a "reserve copy" of the cell's genes

Sporophyte

Spore-producing phase, Diploid

The plasmodium eventually produces sporangia, which in turn produce haploid

Spores

Sporozoans are members of the phylum ____

Sporozoa

Holdfast

Structure that attaches alga to the bottom

Why are algae such a wide range of colors?

The accessory pigments in algae reflect different wavelengths of light than chlorophyll.

What is biologist Lynn Margulis's hypothesis about where the first protists came from?

The first eukaryotic cells may have evolved from a symbiosis of several cells. Mitochondria and chloroplasts found in eukaryotic cells may be descended from aerobic and photosynthetic prokaryotes that began to live inside larger cells.

What are the most important differences among the three phyla of multicellular algae?

The most important involve their photosynthetic pigments.

Within a large population, how does conjugation benefit ciliates?

The process helps to create and maintain genetic diversity.

What occurs in the process known as alternation of generations?

The process involves switching back and forth between haploid and diploid stages during an organism's life cycle.

What kind of protists are classified in the phylum Zoomastigina?

They are animal-like protists that swim using flagella.

How do plantlike protists make much of the diversity of aquatic life possible?

They are at the base of the food chain.

What are accessory pigments?

They are compounds that absorb light at different wavelengths than chlorophyll.

How do amoebas capture and digest food?

They surround a food particle or cell and take it inside themselves to form a food vacuole. Once inside the cell, the material is digested rapidly.

What do scientists think is the connection between mosses and green algae?

They think mosses and green algae share an algaelike ancestor from millions of years ago.

What do sarcodines use pseudopods for?

They use pseudopods for feeding and movement.

What do ciliates use cilia for

They use them for feeding and movement.

Is the following sentence true or false? Some zooflagellates have a sexual life cycle.

True

Circle the letter of each sentence that is true about chrysophytes.

a. The cell walls of some contain the carbohydrate pectin. c. They generally store food in the form of oil. d. Some form threadlike colonies.

Circle the letter of each sentence that is true about sporozoans.

a. They are parasitic. b. They do not move on their own d. They reproduce by means of sporozoites

Circle the letter of each sentence that is true about euglenophytes.

a. They are remarkably similar to zooflagellates. b. They possess chloroplasts. d. They have two flagella

Circle the letter of each sentence that is true about red algae. a. They can grow in the ocean at depths up to 260 meters. b. Most are unicellular. c. All are red or reddish-brown. d. Coralline algae play an important role in coral reef formation.

a. They can grow in the ocean at depths up to 260 meters. d. Coralline algae play an important role in coral reef formation.

Circle the letter of each example of a sarcodine.

a. foraminiferan c. amoeba d. heliozoan

fungus like protists get nutrients by

absorbing things from dead or decayed matter

Plantlike protists are commonly called ______

algae

the switching back and forth between a diploid and a haploid stage in a life cycle is called an

alteration of generation

The best known sarcodines are the _____

amoebas

what effect did the evolution of diff forms of chlorophyll have in algae

an increase in the range of depths at which algae can live

multicellular protists are grouped w unicellular protists bc multicellular protists

are so similar to unicellular protists

Circle the letter of each sentence that is true about protists.

b. All cells have a nucleus. c. All cells have membrane-bound organelles.

Circle the letter of each sentence that is true about dinoflagellates. a. They generally have one flagellum. b. Many species are luminescent. c. Most reproduce by binary fission.

b. Many species are luminescent. c. Most reproduce by binary fission.

Circle the letter of each sentence that is true about diatoms. a. They are very rare in almost all environments. b. Their cell walls are rich in silicon. c. They are shaped like a petri dish or flat pill box. d. They are among the most abundant organisms on Earth.

b. Their cell walls are rich in silicon. c. They are shaped like a petri dish or flat pill box. d. They are among the most abundant organisms on Earth.

Amoebas reproduce by means of

binary fission

red algae lack flagella and

centrioles

which substances allow algae to harvest and use the energy from sunlight

chlorophyll and accessory pigments

many members of the phylum pyrrophyta which are also referred to as ________ are luminescent

dinoflagellates

some products derived from algae

drugs, chemicals, plastics, ice cream, paints

Is the following sentence true or false? Algae include only multicellular organisms.

false

organisms that break down organic material include the

fungus like protists

in the life cycle of the green alga uvla, the phase that produces male and female gametes is known as a

gametophyte

what very large type of algae lives off the coasts

giant kelp

Zooflagellates reproduce asexually by means of________

mitosis and cytokinesis .

Euglenas have a tough, intricate membrane called a(an) ___

pellicle

euglenas have an intricate, folded cell membrane called a

pellicle

the population of all photosynthetic organisms found near the surface of the ocean are called

phytoplankton

The first eukaryotic organisms on Earth were____

protists

the work of fungus like protists and other decomposers is important in improving the quality of

topsoil

Is the following sentence true or false? Some animal-like protists recycle nutrients by breaking down dead organic matter

true

the fungus like protists that thrive on dead or decaying matter in the water are

water molds