BIOL 1202 Exam 3

Protists are ____.

eukaryotes

Are eukaryotic organelles more or less complex than prokaryotic cell?

more complex

What is the organism that is in most eukaryotic lineages?

protists (unicellular)

Name these protists from left to right.

Slime mold, amoeba, euglena, dinoflagellate, paramecium, diatom, macroalga

Photoautotroups

contain chloroplasts

Heterotrophs

absorb organic molecules or ingest food

Mixotrophs

combine photosynthesis and heterotrophism

How do protists reproduce?

sexually and asexually

What four groups are all eukaryotes (including) protists separated into?

excavata, SAR (stramenopiles, alveolates, and rhizarians), archaeplastida, unikonta

Endosymbiosis

a relationship between two species in which one organism lives inside the cell or cells of the other organism (the host)

What is derived from prokaryotes and how?

mitochondria and plastids, prokaryotes were engulfed by ancestors of early eukaryotic cells

What specifically did mitochondria evolve from?

endosymbiosis of an alpha proteobacterium

What specifically did plastids evolve from?

endosymbiosis of a photosynthetic cyanobacteria

Excavata

diplomonads, parabasalids, euglenozoans

Why was this group given the name excavata?

some members have an “excavated” feeding grove on one side of the body

What is unique about diplomonads and parabasalids?

they lack plastids and have modified mitochondria; most live in aerobic environments

Diplomonads

mitochondria called mitosomes, derive energy from anaerobic biochemical pathways, are often parasites

Parabasalids

have a reduced mitochondria called hydrogenosomes, generate some energy anaerobically

Trichomonas vaginalis

a sexually transmitted parasite

Name these from left to right.

“textbook” mitochondrion, anaerobic mitochondrion, hydrogenosome, mitosome

What is unique about euglenozoans?

they have a spiral or crystalline rode inside their flagella

Euglenozoans

predatory heterotrophs, photosynthetic autotrophs, mixotrophs, and parasites

What is unique about kinetoplastids?

have a single mitochondrion with an organized mass of DNA called kintoplast

Trypanosomes

evade host immune responses by producing cell-surface proteins with different molecular structures in each generation

Euglenids

can be autotrophic or heterotrophic

SAR

stramenopiles, alveolates, rhizarians

Stramenopiles

photosynthetic organisms, examples are diatoms, golden algae, and brown algae

Diatoms

unicellular algae

Brown algae

largest and most complex algae; multicellular and often marine (seaweed)

Alveolates

dinoflagellates, apicomplexans, ciliates

Dinoflagellates

aquatic phototrophs, mixotrophs, and heterotrophs (“red tides”)

Apicomplexans

parasites of animals, spread as sporozoites (Plasmodium causes malaria)

Ciliates

a large varied group of protists

Rhizarians

many are amoebas, protists

What do rhizarians consist of?

radiolarians, forams, cerrozoans

Radiolarians

mostly marine protists

Forams

named for their porous shells called “tests”, made of calcium carbonate (seashells)

Archaeplastida

red algae, green algae, and plants

Unikonta

animals, fungi, and some protists; includes two clades (amoebozoans and opisthokonts)

Amoebozoans

lobe or tube-shaped amoebas (slime molds, tubulinids, and entamoebas)

Slime mold A

Plasmodial slime molds (unicellular)

Slime mold B

Cellular slime molds (motile)

Tubulinids

unicellular protists, heterotrophic

Entamoebas

parasites of vertebrates and some invertebrates

Symbiotic protists

some benefit their host and some are parasitic

Photosynthetic producer protists

convert CO2 to organic compounds

When did cyanobacteria and protists likely exist on land?

1\.2 million years ago

When did small plants, fungi, and animals emerge on Earth?

within the last 500 years

Where does Earth’s oxygen come from?

marine microbes, land plants, and macro algae (kelp)

Which plant species produces the most oxygen?

snake plant

What are the closest relatives to plants?

green algae (charophytes); rings of cellulose synthesizing proteins, structure of flagellated sperm, and formation of a phragmoplast

Sporopollenin

a durable polymer layer that prevents zygotes from drying out

What are the benefits for charophytes moving to land?

unfiltered sunlight, more plentiful CO2, and nutrient rich soil

What were the challenges for charophytes moving to land?

scarcity of water and lack of structural support against algae

Alteration of Generations

gametophyte generation (haploid and produces haploid gametes by mitosis) and fusion (diploid sporophyte which produces haploid spores by meiosis)

Label this picture

meiosis, fertilization, spore, gametophyte, mitosis, gamete from another plant, spore, gamete, fertilization, zygote, mitosis, sporophyte

How are nutrients transferred from parent to embryo?

placental transfer cells

Why are plants called embryophytes?

because of the dependency of the embryo on the parent

Spoeocytes

diploid cells that undergo meiosis to generate haploid spores

Archegonia

female gametangia, produce a single non-motile egg

Antheridia

male gametangia, produce and release sperm

Apical Meristems

within this plants sustain continual growth in length by repeated cell division

Cuticle

a waxy covering of the epidermis

Stomata and Guard cells

specialized cells that allow for gas exchange between the outside air and the plant

What do the appearance of plant spores in the fossil record indicate?

that plants colonized land at least 470 million years ago

Vascular tissue

cells joined into tubes for the transport of water and nutrients

Bryophytes

nonvascular plants

Seedless vascular plants

lycophytes (club mosses and their relatives) and monilophytes (ferns and their relatives)

Seed

an embryo and nutrients surrounded by a protective coat

Seeded vascular plants

gymnosperms ('“naked seeds, not in chambers) and angiosperms (“enclosed seeds”, develop inside chambers)

Bryophytes

liverworts, mosses, and hornworts

Rhizoids

anchor gametophytes to substrate

Sporophyte vs. Gametophyte

What does a sporophyte consist of?

a foot, a seta (stalk), and a sporangium (capsule)

What were the prominent types of vegetation during the first 100 million years of plant evolution

bryophytes

What do the earliest fossils of vascular plants date to?

425 million years ago

Xylem

conducts most of the water and minerals and includes tube-shaped cells called tracheids

Lignin

strengthens water conducting cells and provides structural support

Phloem

has cells arranged into tubes that distribute sugars, amino acids, and other organic compounds

Roots

organs that anchor vascular plants, absorb water and nutrients from soil

Leaves

organs that increase the surface area of vascular plants, maximizing photosynthesis

Microphylls

small leaves with a single vein

Megaphylls

larger leaves with a highly branched vascular system

Sporophylls

modified leaves with sporangia

Sori

sporangia clusters on sporophyll undersides

Strobili

cone-like structures formed from groups of sporophylls

Homosporous

producing one type of spore that develops into bisexual gametophyte

Megaspores

produced by heterosporous species, give rise to female gametophytes

Microspores

give rise to male gametophytes

Lycophyta

club mosses, spike mosses, and quillworms

Monilophyta

ferns, horsetails, and whisk ferns and their relatives

When did seed plants originate?

360 million years ago

Reduced gametophytes

develop within the walls of spores that are retained with tissues of the parent sporophyte, protects the developing gametophyte

Ovule

consists of megasporangium, megaspore, and one or more protective integuments

How many integuments do gymnosperm megasporangia and angiosperm megasporangia usually have

gymnosperm megasporangia have 1 and angiosperm megasporangia have 2

Pollen grain

what a microspore develops into, consists of a male gametophyte enclosed within the pollen wall

Pollination

the transfer of pollen to the part of a seed plant containing the ovules

Pollen tube

discharges sperm into the female gametophyte within the ovule

What does gymnosperm mean?

“naked seed”