General Biology II Exam 2 - Protistans

protistssss

What are protists?

• protists are a very diverse, polyphyletic group. all eukaryotes are considered protists except fungi, animals, and land plants

What defines a protist?

• eukaryotic cells

  • have a membrane-bound nucleus and organelles

• mostly unicellular

  • most consist of one cell

• some form colonies

  • groups of cells living together

• some are coenocytic

  • have multiple nuclei within one mass of cytoplasm

• few are multicellular

T/F Most protists are unicellular

True

T/F Most protists are multicellular

False; most are unicellular

All eukaryotes are considered protists except ____, _____, and ______

fungi, animals, and land plants

What are some of protist’s major evolutionary innovations?

A membrane-bound nucleus that contains DNA, internal membranes and organelles that compartmentalize cell functions, mitochondria which generate ATP (energy through cellular respiration, chloroplasts which produce carbohydrates through photosynthesis, a cytoskeleton that provides cell structure and helps with movement, cilia and flagella used for movement, sexual reproduction methods involving meiosis and syngamy, multicellularity & division of labor aka different cells specialize in different functions, increase in organism size, change from unicellular to colonial to multicellular, change from simple to complex communities, and greater compartmentalization of cells and their functions

What is syngamy?

the fusion of gametes

What does the nucleus do for protists?

contains DNA

What does the endomembrane system consist of and do for protists?

consists of internal membranes and organelles that compartmentalize cell functions

What does the mitochondria do for protists?

generate ATP (energy) through cellular respiration

What do chloroplasts do for protists?

produce carbohydrates through photosynthesis

What does the cytoskeleton do for protists?

provides cell structure and helps with movement

What do cilia, flagella, and pseudopodia do for protists?

structures used for movement

What do protists do that allow them to survive so many disparate environments

protists survive in diverse environments because they have varied nutritional strategies, movement structures, specialized organelle, and the ability to form protective cysts under unfavorable conditions

What are the specific adaptations protists have that make it so they can live in extreme conditions?

different types of nutrition (they can be autotrophs, chemoheterotrophs, or mixotrophs), different methods of movement (may use flagella, cilia, or pseudopodia, while some are non-motile), some form protective cysts to survive harsh conditions like drying out, or high UV levels, contractile vacuoles that help regulate water balance by expelling excess water, and their ability to adapt to different habitats (can live in aquatic environments, moist soils, decaying organic matter, and within plants and animals as parasites)

How can protists get nutrition?

as autotrophs, chemoheterotrophs, or mixotrophs

T/F Protists are heterotrophs

False; cannot be heterotrophs

T/F Protists can be autotrophs

True

T/F Protists can be chemoheterotrophs

True

T/F Protists can be mixotrophs

True

What structures do protists use for movement?

cilia, flagella, or pseudopodia

T/F Some protists are non-motile

True

What do protists form cysts for?

to protect them from harsh conditions like high UV or drying out

What do protists use to protect them from harsh conditions?

Protective cysts

What do protists use to help regulate water balance by expelling excess water?

contractile vacuoles

T/F Protists are not very adaptive organisms

False; highly adaptable

T/F Protists can only live within aquatic environments

False; can also live in moist soil, decaying organic matter, and inside plants and animals as parasites

How did protists change to how they are today?

• protists originated from early eukaryotic ancestors. membrane infolding helped form internal cell structures, and endosymbiosis led to mitochondria and chloroplasts. over billions of years, eukaryotes diversified into many different lineages. the exact base of the evolutionary tree remains unclear

Protists originate from ______

Eukaryotes

Chemical evidence of protists’ early eukaryotic ancestors dates back about _______ years ago

2.7 billion

Fossils of protists’ early eukaryotic ancestors date back about _______ years ago

2.1 billion

How did membrane infolding or invagination help protists become how they are now?

the cell membrane folded inward, forming internal structures such as the nuclear envelope and endomembrane system

What is invagination?

the process or condition in which a surface, tissue, or cell layer folds inward upon itself to form a pocket, pouch, tube, or cavity

What is endosymbiosis?

an ancestral eukaryotic cell engulfed bacteria that survived inside it and formed a mutually beneficial relationship

Mitochondria evolved from ______

alpha-proteobacteria

Chloroplasts evolved from ________

cyanobacteria

T/F Mitochondria evolved from alpha-proteobacteria

True

T/F Mitochondria evolved from cyanobacteria

False; alpha-proteobacteria

T/F Chloroplasts evolved from cyanobacteria

True

T/F Chloroplasts evolved from alpha-proteobacteria

False; cyanobacteria

Mitochondria’s evolution from alpha-proteobacteria and chloroplast’s evolution from cyanobacteria are both examples of ______

endosymbiosis

What are the 7 major lineages of eukaryotes ?

Amoebozoa, Opisthokonta, Excavata, Plantae, Rhizaria, Alveolata, and Stramenopila

What is Amoebozoa’s apomorphy?

• cells lack cell walls

• when portions of the cell extend outward to move the cell, they form large lobes

• includes amoebas and slime molds

What is Opisthokonta’s apomorphy?

• reproductive calls have a single flagellum at their base

• cristae inside mitochondria are flat not tube shaped

• includes animals, fungi, and choanoflagellates

What is Excavata’s apomorphy?

• an pronounced feeding grove on one side of the cell

• no functioning mitochondria are present although genes derived from mitochondria are found in nucleus

• includes diplomonads, parabasalids, and euglenozoans

What is Plantae’s apomorphy?

• cells have chloroplasts with a double membrane

• includes red algae, green algae, and land plants

What is Rhizaria’s apomorphy?

• often have thin, threadlike or needlelike pseudopodia

• cells lack cell wall although some produce an elaborate shell-like covering

• when portions of the cell extend outward to move the cell, they are slender in shape

• includes foraminiferans

What is Alveolata’s apomorphy?

• cells have sac-like structures called alveoli that form a continuous layer just beneath the plasma membrane

• alveoli are thought to provide support

• includes ciliates, dinoflagellates, and apicomplexans

What is Stramenopila’s apomorphy?

• characteristic hairy (tinsel) flagella

• includes diatoms, brown algae, and oomycetes

T/F Amoebozoa’s apomorphy is cells lacking cell walls, and when portions of the cell extend outward to move the cell, they form large lobes

True

T/F Amoebozoa’s apomorphy is cells have sac-like structures called alveoli that form a continuous layer just beneath the plasma membrane, and these alveoli are thought to provide support

False; Alveolata

T/F Amoebozoa’s apomorphy is reproductive cells have a single flagellum at their base, and cristae inside mitochondria are flat, not tube-shaped

False; Opisthokonta

T/F Opisthokonta’s apomorphy is reproductive cells have a single flagellum at their base, and cristae inside mitochondria are flat, not tube-shaped

True

T/F Opisthokonta’s apomorphy is cells lacking cell walls, and when portions of the cell extend outward to move the cell, they form large lobes

False; Amoebozoa

T/F Opisthokonta’s apomorphy is characteristic hairy (tinsel) flagella

False; Stramenopila

T/F Excavata’s apomorphy is a pronounced feeding groove on one side of the cell, and no functioning mitochondria are present, although genes derived from mitochondria are found in the nucleus

True

T/F Excavata’s apomorphy is cells have chloroplasts with a double membrane

False; Plantae

T/F Excavata’s apomorphy is often thin, threadlike or needlelike pseudopodia, cells lack a cell wall, although some produce an elaborate shell-like covering, and when portions of the cell extend outward to move the cell, they are slender in shape

False; Rhizaria

T/F Plantae’s apomorphy is cells have chloroplasts with a double membrane

True

T/F Plantae’s apomorphy is a pronounced feeding groove on one side of the cell, and no functioning mitochondria are present, although genes derived from mitochondria are found in the nucleus

False; Excavata

T/F Plantae’s apomorphy is cells have sac-like structures called alveoli that form a continuous layer just beneath the plasma membrane, and these alveoli are thought to provide support

False; Alveolata

T/F Rhizaria’s apomorphy is often thin, threadlike or needlelike pseudopodia, cells lack a cell wall, although some produce an elaborate shell-like covering, and when portions of the cell extend outward to move the cell, they are slender in shape

True

T/F Rhizaria’s apomorphy is cells lacking cell walls, and when portions of the cell extend outward to move the cell, they form large lobes

False; Amoebozoa

T/F Rhizaria’s apomorphy is characteristic hairy (tinsel) flagella

False; Stramenopila

T/F Alveolata’s apomorphy is cells have sac-like structures called alveoli that form a continuous layer just beneath the plasma membrane, and these alveoli are thought to provide support

True

T/F Alveolata’s apomorphy is reproductive cells have a single flagellum at their base, and cristae inside mitochondria are flat, not tube-shaped

False; Opisthokonta

T/F Alveolata’s apomorphy is cells have chloroplasts with a double membrane

False; Plantae

T/F Stramenopila’s apomorphy is characteristic hairy (tinsel) flagella

True

T/F Stramenopila’s apomorphy is often thin, threadlike or needlelike pseudopodia, cells lack a cell wall, although some produce an elaborate shell-like covering, and when portions of the cell extend outward to move the cell, they are slender in shape

False; Rhizaria

T/F Stramenopila’s apomorphy is a pronounced feeding groove on one side of the cell, and no functioning mitochondria are present, although genes derived from mitochondria are found in the nucleus

False; Excavata

What does Unikonta mean?

one flagellum

What does Bikonta mean?

two flagella

What Eukaryotic lineages are Unikonta?

Amoebozoa and Opisthokonta

What Eukaryotic lineages are Bikonta?

All lineages except Amoebozoa & Opisthokonta

T/F Amoebozoa is apart of Unikonta

True

T/F Opisthokonta is apart of Unikonta

True

T/F Amoebozoa is apart of Bikonta

False; Unikonta

T/F Opisthokonta is apart of Bikonta

False

T/F Unikonta encompasses all lineages beside Amoebozoa and Opisthokonta

False; only encompasses those two

T/F Excavata is apart of Bikonta

True

T/F Excavata is apart of Unikonta

False; Bikonta

T/F Plantae is apart of Bikonta

True

T/F Planate is apart of Unikonta

False; Bikonta

T/F Rhizaria is apart of Unikonta

False; Bikonta

T/F Rhizaria is apart of Bikonta

True

T/F Alveolata is apart of Unikonta

False; Bikonta

T/F Alveolata is apart of Bikonta

True

T/F Stramenopila is apart of Bikonta

True

T/F Stramenopila is apart of Unikonta

False; Bikonta