Survey of Eukaryotes (Ch.12)

Question 1

What is the difference between a haploid and a diploid nucleus?

Answer 1

A haploid nucleus has one copy of each chromosome, while a diploid nucleus has two copies of each chromosome.

Question 2

How does mitosis divide the nucleus in eukaryotic cells?

Answer 2

Mitosis divides the nucleus in four phases: prophase, metaphase, anaphase, and telophase, resulting in two nuclei with the same ploidy as the original.

Question 3

What is meiosis and what does it result in?

Answer 3

Meiosis is a nuclear division that results in four nuclei, each with half the ploidy of the original.

Question 4

What is cytokinesis?

Answer 4

Cytokinesis is the division of the cytoplasm, which can occur during or after nuclear division.

Question 5

What are coenocytes?

Answer 5

Coenocytes are multinucleate cells that result from repeated mitoses without cytokinesis.

Question 6

What is schizogony?

Answer 6

Schizogony is a process in which some microbes undergo multiple mitoses to form a multinucleate schizont, which then undergoes cytokinesis to produce daughter cells.

Question 7

What factors are considered in classifying eukaryotic microbes today?

Answer 7

Eukaryotic microbes are classified based on nucleotide sequences and ultrastructural features.

Question 8

What are protozoa?

Answer 8

Protozoa are eukaryotic, unicellular organisms that lack cell walls.

Question 9

What is the trophozoite stage in protozoa?

Answer 9

The trophozoite is the motile, feeding stage of a protozoan.

Question 10

What is the cyst stage in protozoa?

Answer 10

The cyst is a resting stage that is resistant to environmental changes.

Question 11

What is the main mode of nutrition for most protozoa?

Answer 11

Most protozoa are chemoheterotrophs, obtaining energy from chemicals and carbon from other organisms.

Question 12

What are dinoflagellates and euglenoids?

Answer 12

Dinoflagellates and euglenoids are photoautotrophic protozoa that perform photosynthesis.

Question 13

What are gametocytes in protozoa?

Answer 13

Gametocytes are reproductive cells that fuse to form a zygote during sexual reproduction in some protozoa.

Question 14

Name the six groups of protozoa.

Answer 14

Parabasalids, diplomonads, euglenozoa, alveolates, rhizaria, and amoebozoa.

Question 15

What is unique about parabasalids?

Answer 15

Parabasalids have a Golgi body-like structure called a parabasal body.

Question 16

What is a defining feature of diplomonads?

Answer 16

Diplomads lack mitochondria, Golgi bodies, and peroxisomes.

Question 17

What are euglenids?

Answer 17

Euglenids are unicellular flagellated euglenozoa that store food as paramylon and have eyespots used in positive phototaxis.

Question 18

What is a kinetoplast?

Answer 18

A kinetoplast is a large, apical mitochondrion containing a region of DNA, found in kinetoplastids.

Question 19

What are alveolates?

Answer 19

Alveolates are protozoa with cavities beneath their cell surfaces and include ciliates, apicomplexans, and dinoflagellates.

Question 20

What are amoebas classified as?

Answer 20

Amoebas are classified into the kingdoms Rhizaria and Amoebozoa.

Question 21

What is the difference between rhizaria and amoebozoa?

Answer 21

Rhizaria amoebas have threadlike pseudopods and may have shells, while amoebozoa have lobe-shaped pseudopods.

Question 22

What are fungi and what type of nutrition do they use?

Answer 22

Fungi are chemoheterotrophic eukaryotes with cell walls, usually composed of chitin, and acquire nutrients through absorption.

Question 23

What are hyphae?

Answer 23

Hyphae are tubular filaments that make up the body of molds.

Question 24

What is a mycelium?

Answer 24

A mycelium is a tangled mass of hyphae.

Question 25

What is the difference between septate and aseptate hyphae?

Answer 25

Septate hyphae have cross walls, while aseptate hyphae do not.

Question 26

What is a dimorphic fungus?

Answer 26

A dimorphic fungus can exist in either a moldlike (with hyphae) or yeastlike form, depending on environmental conditions.

Question 27

How do most fungi reproduce asexually?

Answer 27

Most fungi reproduce asexually by budding or via asexual spores.

Question 28

What are the sexual reproduction structures in fungi of the division Zygomycota?

Answer 28

Fungi in Zygomycota produce rough-walled zygosporangia during sexual reproduction.

Question 29

What are examples of fungi in the Ascomycota division?

Answer 29

Fungi in Ascomycota produce ascospores within sacs called asci. Examples include yeasts and molds like Saccharomyces.

Question 30

What is the Basidiomycota division known for?

Answer 30

Basidiomycota fungi have fruiting bodies called basidiocarps, which include mushrooms and puffballs.

Question 31

What are Deuteromycetes?

Answer 31

Deuteromycetes (imperfect fungi) are a group of fungi without a known sexual stage.

Question 32

What are lichens and why are they important?

Answer 32

Lichens are symbiotic associations between fungi and photosynthetic organisms (like green algae or cyanobacteria) and are important for their environmental and ecological roles.

Question 33

What are algae and why are they studied in microbiology?

Answer 33

Algae are photosynthetic organisms, and studying them helps understand primary producers in ecosystems and their relationship with other organisms.

Question 34

What is alternation of generations in algae?

Answer 34

It is a reproductive cycle in which a haploid body alternates with a diploid body.

Question 35

What are the major divisions of algae?

Answer 35

Chlorophyta (green algae), Rhodophyta (red algae), Phaeophyta (brown algae), and Chrysophyta (golden algae, diatoms).

Question 36

What is the storage product of green algae?

Answer 36

Green algae store food as starch, similar to land plants.

Question 37

What are diatoms and what is unique about their structure?

Answer 37

Diatoms are a type of golden algae with silica cell walls that form two nesting halves called frustules.

Question 38

What are parasitic helminths?

Answer 38

Parasitic helminths are parasitic worms that are important to microbiologists due to their microscopic infective stages.

Question 39

What is the role of arthropod vectors?

Answer 39

Arthropod vectors carry and transmit pathogens, either mechanically or biologically.

Question 40

What is the difference between mechanical and biological vectors?

Answer 40

Mechanical vectors merely carry pathogens, while biological vectors also serve as hosts for the pathogens.

Question 41

What is the significance of ticks and mites in microbiology?

Answer 41

Ticks and mites are arachnids that can transmit various pathogens to humans and other animals.

Question 42

What are the characteristics of parasitic worms?

Answer 42

Parasitic worms are typically multicellular, have complex life cycles, and can cause diseases in humans and animals.

Question 43

Why do we study helminths in microbiology?

Answer 43

We study helminths because they cause significant human diseases, and their microscopic infective stages are of interest.

Question 44

What role do cysts and trophozoites play in protozoan diseases?

Answer 44

Cysts are the resting form, while trophozoites are the active, feeding form of protozoans, playing key roles in transmission and infection.

Question 45

What is the difference between definitive, intermediate, and dead-end hosts?

Answer 45

The definitive host is where the parasite reaches maturity, the intermediate host is where the parasite undergoes developmental stages, and the dead-end host cannot transmit the parasite to others.