Bio Chapter 21

Photosynthetic organisms include __________.

both protists and bacteria

Which of the following is a protist?

Alga

Which of the following is an aquatic protist?

Algae

How do algae and heterotrophic protists differ?

Algae are photosynthetic, whereas heterotrophic protists get their food from consuming other organisms.

Which of the following would be classified as a prokaryotic single-celled organism?

Bacteria

Sewage treatment plants use __________ to break down sewage.

Bacteria and fungi

A virus is characterized by all except which one of the following?

Enzymes of respiration

Which of the following are the domains of life?

Eukarya, Archaea, Bacteria

Which of the following is most likely to be found in an extreme environment, like one with very high temperatures?

Extremophiles

Instead of sterilizing your water bottles after your weekend camping trip as you usually do, you decide to put the few remaining drops of water on a microscope slide. You observe a diverse group of single-celled creatures. After consulting a few books, you are pretty certain the organisms are not archaeal extremophiles. Why not?

Extremophiles are unlikely to be found in areas where you would go for a weekend camping trip.

Instead of sterilizing your water bottles after your weekend camping trip as you usually do, you decide to put the few remaining drops of water on a microscope slide. You observe a diverse group of single-celled creatures. Suppose you determine that your creatures are eukaryotic and acquire energy by decomposing organic matter. What type of protist would they be?

Fungi-like

Bacteria are __________.

Generally haploid, unicellular organisms

Overuse of antibiotics in medicine and agriculture can be dangerous because __________.

It may increase the occurrence of antibiotic resistant bacteria

Bacteria within the human body __________.

May help with the digestion of food

Are viruses alive?

No, their lack of replicative ability prevents classification as alive.

The simplest of the eukaryotes are __________.

Protists

Which of the following would be an animal-like protist?

Protozoan

Instead of sterilizing your water bottles after your weekend camping trip as you usually do, you decide to put the few remaining drops of water on a microscope slide. You observe a diverse group of single-celled creatures. You try to determine more about your mysterious creatures. Which of the following attributes will tell you definitively whether they are prokaryotes or eukaryotes?

Sexual reproduction

Which of the following is a noncellular infectious agent?

Viruses

Microscopic organisms (microbes) __________.

all listed responses are correct - provide sources of nitrogen for plants to use, produce more than half of the world's oxygen, act as decomposers of organic material, are vital to the digestion of some animals

Heterotrophic protists can move by the use of __________.

all of the listed responses are correct - pseudopods, flagella, cellular extensions, cilia

Alexander Fleming discovered penicillin when he __________.

found that a fungus was growing in his bacterial culture

The emergence of sexual reproduction among the protists was important primarily because __________.

it increased genetic variation

When a virus infects a cell, it forces the cell to manufacture __________.

more viral particles

Viruses are part of the __________.

none of the listed responses are correct - Because all living organisms have cells and viruses lack cells, they have no place in the Tree of Life.