Deck 29: Protistans

Question 1

Which of these is a green alga?

A) Volvox
B) Gelidium
C) Euglena
D) Paramecium
E) Plasmodium

Answer 1

Volvox  belongs to the family Volvocaceae and genus chlorophyte green algae, found in freshwater. It forms sphere-shaped colonies with 50,000 cells.
Gelidium  is red alga belongs to the division rhodophyta and class rhodophyceae, branching is irregular, or arises in rows on either side of the central stem.
Hence, the option (b) is not the correct answer.
Euglena  is a single-celled flagellate belongs to the class Euglenoidea, found in fresh and salt waters.
Hence, the option (c) is not the correct answer.
Paramecium is single-celled organism belongs to the class Oligohymenophorea and family parameclidae and naturally found in the aquatic habitats.
Hence, the option (d) is not the correct answer.
Plasmodium belongs to a genus of parasitic protozoans of the sporozoan and subclass Coccidia, which infects red blood cells in mammals, birds, and reptiles and cause malaria.
Hence, the option (e) is not the correct answer.
Green algae  are a huge, familiar grouping of algae consisting of chloroplasts that include chlorophyll a and b, gives bright green color, other pigments   xanthophyll and beta carotene present in stacked thylakoids. Volvox  belongs to the family Volvocaceae and genus chlorophyte green algae. It forms sphere-shaped colonies with 50,000 cells. They live in freshwater.
Hence, the correct answer is .

Question 2

Choose the best answer for each question.
Dinoflagellates

A) usually reproduce sexually.
B) often have protective cellulose plates.
C) are insignificant producers of food and oxygen.
D) have cilia instead of flagella.
E) tend to be larger than brown algae.

Answer 2

Dinoflagellates are the important phytoplankton members. These cause red tides in the sea. Gonyaulax is a dinoflagellate causes red tides producing a toxin. The dinoflagellates reproduce by both asexual and sexual means.
The option (a) is incorrect.
The dinoflagellates are the diverse group and produce red tides in sea when they increase in number largely producing an algal bloom. The dinoflagellates posses protective cellulose plates impregnated with silica and make them hard shells.
Hence, the option (b) is correct
Dinoflagellates are the major members of the phytoplankton in marine and fresh water echo systems they are photosynthetic. They are insignificant producers of food and oxygen is false because they posses chlorophyll, red and blue pigments and carryout photosynthesis to produce food and oxygen.
The option (c) is incorrect.
Dinoflagellates are phytoplankton and are minute in size than the red algae. The red algae are multicellular and range from small filaments to leafy structures. Brown algae are macroscopic multicellular seaweeds. The Dinoflagellates are smaller than both red algae and red algae.
Hence, the option (d) is incorrect.

Question 3

Ciliates

A) move by pseudopods.
B) are not as varied as other protists.
C) feed and move using cilia.
D) do not divide by binary fission.
E) are closely related to the radiolarians.

Answer 3

Ciliates contain cilia are usually short, numerous cylindrical structures on the surface of the cell which are rhythmically moving the cell forward or reverse and also helps in capturing of food.
Pseudopodia or pseudopods are temporary cytoplasm filled protrusions of unicellular protists. They used for ingesting nutrients or motility.
Hence, the option (a) is not the correct answer.
Ciliates are a group of protozoans distinguished by the presence of hair-like structures known as cilia, which are similar to eukaryotic flagella, but shorter in size and present in huge numbers. Cilia present in all members of the group and used in crawling, feeding, sensation, swimming and attachment.
Hence, the option (b) is not the correct answer.
Ciliates reproduce asexually by binary fission. During binary fission, the micronucleus involved in mitosis and the macronucleus elongates and undergoes amitosis.
Hence, the option (d) is not the correct answer.
Radiozoa are also called  radiolaria found as zooplankton throughout the ocean, contains diameter 0.1-0.2 mm that makes intricate mineral skeletons, with a central capsule dividing the cell into the outer and inner portions of  ectoplasm and endoplasm.
Hence, the option (e) is not the correct answer.
Ciliates are also called protozoans, contain cilia are usually short, numerous cylindrical structures on the surface of the cell which are rhythmically moving the cell forward or reverse. In addition to locomotion, cilia also help in capturing of food.
Hence, the correct answer is .

Question 4

Which of the following is most closely related to the land plants?

A) dinoflagellates
B) charophytes
C) chlorophytes
D) euglenids

Question 5

Protists that may lack mitochondria and possess deep oral grooves are known as

A) excavates.
B) apicomplexans.
C) alveolates.
D) amoeboids.
E) ciliates.

Question 6

Plasmodial and cellular _____ are important decomposers that have an amoeboid vegetative state.

A) brown algae
B) water molds
C) filamentous algae
D) slime molds
E) red algae

Question 7

Through what process did eukaryotic cells gain chloroplasts and mitochondria?

A) engulfment
B) endosymbiosis
C) endocytosis
D) phagocytosis
E) conjugation

Question 8

All protists are

A) photosynthetic.
B) parasites.
C) single-celled.
D) eukaryotes.
E) All of these are correct.

Question 9

Which of the following represents an organism that uses decomposition as its mode of nutrition?

A) parasite
B) saprotroph
C) autotroph
D) All of these are correct.

Question 10

Which of the following is not a characteristic of Microsporidia?

A) parasitic
B) lives in host cells
C) multicellular
D) can infect invertebrates like insects
E) can infect vertebrates like humans

Question 11

Which of the following is not a characteristic of chytrids?

A) They have flagellated spores.
B) They have flagellated gametes.
C) They can live on very dry land.
D) They can be single cells.
E) They can be animal parasites.

Question 12

The collective mass of hyphae is called a

A) sporophyte.
B) mycelium.
C) ascocarp.
D) lichen.

Question 13

Mycorrhizae

A) are a type of lichen.
B) are mutualistic relationships.
C) help plants gather solar energy.
D) help plants gather inorganic nutrients.
E) Both b and d are correct.

Question 14

Choose the best answer for each question.
Fungi are classified according to

A) sexual reproductive structures.
B) shape of their hyphae.
C) mode of nutrition.
D) type of cell wall.
E) All of the choices are correct.

Question 15

Choose the best answer for each question.
Lichens

A) cannot reproduce.
B) need a nitrogen source to live.
C) are parasitic on trees.
D) are able to live in extreme environments.

Question 16

How does poverty reinforce a high occurrence of African sleeping sickness?

Question 17

How are the economy, ecology, and disease biology of African sleeping sickness interdependent?

Question 18

Why do you think that some species of fungi contain chemicals that are harmful to people?

Question 19

How might an understanding of fungal poisons aid in the development of new drugs for humans?