Biology 172- Exam 1 Review-February 21

What is a protist?

Any eukaryote that is not a fungus, plant or animal

List the taxonomy levels in order

Kingdom Phylum Class Order Family Genus Species

How do protists obtain energy?

Autotrophically, Heterotrophically, Mixotrophically

What is endosymbiosis?

the process in which a unicellular organism engulfs another cell, which becomes an endosymbiont and then organelle in the host cell.

How did mitochondria evolve?

through endosymbiosis of an aerobic prokaryote.

How did plastids evolve?

through endosymbiosis of a photosynthetic prokaryote

Name the four eukaryotic supergroups

Excavata, "SAR" clade, Archaeplastida, Unikonta

Supergroup Excavata

The supergroup Excavata share a similar cytoskeleton and some have an "excavated" feeding groove on the side of the body.

Diplomonads

anaerobic metabolism, two equal-sized nuclei and multiple flagella, reduced mitochondria called mitosomes. example: Giardia intestinalis (lamblia)

Antonie von Leeuwenhoek 1632-1723

father of microbiology, discovered protists and bacteria

Parabasalids

have hydrogenosomes (anaerobic energy), example: Trichomonas vaginalis

Euglenozoans

A diverse clade that includes predatory heterotrophs, photosynthetic autotrophs, and parasites. The main feature distinguishing them is a spiral or crystalline rod inside their flagella. This clade includes the kinetoplastids and euglenids.

Example:Trypanosoma brucei (African sleeping sickness)

Name the four Eukaryotic Supergroups

Excavata, SAR clade, Archaeplastida, Unikonta

Alveolates

SAR clade, have membrane bounded sacs (alveoli) just under the cell membrane. They include dinoflagellates, apicomplexans, and ciliates.

Dinoflagellates

-have two flagella and each cell is reinforced by cellulose plates (cellulose is the main structural molecule in plants, so this is a case of convergent evolution).

-They are abundant components of both marine and freshwater plankton and can be autotrophs, heterotrophs or mixotrophs.

dinoflagellate

identify this microorganism

cartenoid

pigment found in all three domains of life, seen in red algae blooms

What is the "red tide"

A bloom of dinoflagellates, releasing a powerful but short lived toxin, kills lots of fish

What are Apicomplexans?

Specialized parasites of animals, some of which cause serious human diseases.

Reproduction of Apicomplexans

Most have sexual and asexual stages hat require two or more different host species for completion.

How do apicomplexans spread

through their host as infectious cells called sporozoites.

Structure of apicomplexan

One end, the apex, contains a complex of organelles specialized for penetrating host cells and tissues....

The APICAL COMPLEX will connect to the red blood cell

What are the two most common apicomplexans?

Plasmodium and Toxoplasma

What illness is associated with plasmodium?

4 types of malaria

What is the vector for malaria?

Anopheles mosquitoes (through infected blood)

Figures about malaria?

Over 40 percent of the world's population lives in contact with malaria and there are about 200 million cases each year.

Steps of a human infection with malaria

1. A sporozoite form is transmitted from the mosquito to a person's blood.

2. A merozoite form reproduces in the liver and then infects red blood cells.

3. A feeding form consumes the hemoglobin of blood cells.

4.Rupture of cells leads to symptoms of chills and fever.

What is one reason most endemic Hawaiian birds have gone extinct?

avian malaria following introduction of mosquitoes in the 1800's

important characteristics of Toxoplasma gondii

- parasitic alveolate

-affects the host behavior

-ex... rat being comfortable around a cat

ciliates

a large varied group of protists, are named for their use of cilia to move and feed.

example of a ciliate

Paramecium

what is a macronuclei?

part of a ciliate that is responsible for protein subscription

Conjugation in cilliates?

sexual process, physical exchange of genetic material with haploid mICROnuclei, SEPARATE from reproduction

Reproduction in cilliates

binary fission, one cell simply splits into two

what is a micronuclei?

stores the complete genome, is diploid, germ cells, do NOT transcript anything

what does the contractile vacuole do?

osmoregulation... expands to collect, shrinks to expel it

purpose of cilia

locomotion

purpose of food vacuole

digests food particles with aid of lysosomes

oral groove

mouth opening of the paramecium

cell mouth

Opening through which food passes into the gullet of a paramecium.

Stramenophiles

-important autotrophs, some heterotrophs

-most have a hairy and a smooth flagella

-diatoms, golden algae, brown algae

Diatoms

-unicellular algae

-unique two-part, glass-like wall of hydrated silica

-reproduce asexually, occasionally sexually

-approximately 100,000 species

major component of phytoplankton?

diatoms

What is diatomaceous earth?

Ground sedimentary rock made up of the fossilized cell walls of diatoms

Which is the largest, most complex algae, including seaweeds and kelp?

Brown algae

what are cell walls of brown algae made of?

Algin

What is algin used for?

to thicken processed foods

what is a stipe?

a stem-like region between the holdfast and blade of some seaweeds

what is a blade?

place where photosynthesis occurs (leafish) of brown algae

What is a holdfast?

root-like structure, anchors brown algae into water

Supergroup Unikonta

includes animals, fungi, and some protists

Amoebozoans

- amoeba that have lobe- or tube-shaped pseudopodia (foot-like extensions).

-They include single-celled, free living and parasitic amoeba as well as colonial slime molds.

What are plasmodial slime molds?

Amoeba 'supercells' containing many nuclei.

Where do plasmodial slime molds typically inhabit?

Moist soil or decaying vegetation.

How do plasmodial slime molds feed?

By phagocytosis (cell-feeding, engulfing and drawing within).

What are cellular slime molds?

Microscopic amoeba that feed as individual cells.

What do cellular slime molds form to migrate?

Multicellular aggregates.

What do cellular slime molds disperse?

Reproductive spores.

Dictyostelium discoideum

experimental model for studying the evolution of multicellularity

What organelles are associated with the first cases of endosymbiosis?

Mitochondria and plastids

heteromorphic

sporophytes and gametophytes are structurally different

isomorphic

Referring to alternating generations in which the sporophytes and gametophytes look alike, although they differ in chromosome number.

oomycetes

-water molds/friends

-hyphae (multinucleated filaments)

-cell wall of cellulose

-responsible for potato blight

-decomposers and parasites

amoeba

protists that move and feed with pseudopodia

rhizarians

include radiolarians, forams, and cercozoans

forams

A marine protozoan that secretes a shell and extends pseudopodia through pores in its shell

what are foram tests?

porous shells hardened with calcium carbonate, symbiotic algae can live inside.

What are fungi?

-single OR multicellular heterotrophic eukaryotes

How many species of fungi are there?

100,000 known, probably over a million

Habitat of fungi

many habitats including the arctic, tropical rainforest, fresh and salt water. However, most fungi live in soil.

Cell wall of fungi is made of…

chitin (like bug exoskeleton)

Are fungi vascular or non vascular?

nonvascular

Can fungi move?

No, they’re non-motile

biggest organism ever?

honey mushroom Armillaria

What are hyphae?

thin, thread-like filaments that make up the main “body” of the fungus

What are mycelium?

a mass of hyphae

How do SPORES structure relate to their role in ecosystems?

enable fungi to colonize new environments. The spores germinate and grow when conditions are favourable.

How do hyphae decompose?

EXTRACELLULAR DIGESTION; secret enzymes into the environment to break materials down, then absorb said materials.

How are most hyphae cells divided?

By septa, with pores allowing movement of organelles.

What are Coenocytic fungi?

Have hyphae that lack septa and have a continuous cytoplasmic mass with hundreds or thousands of nuclei.

fungi can be…

decomposers, parasites, predators

Example of a parasitic fungi

ringworm

Unique factor of some predatory fungi

have specialized hyphae for capturing prey.

What are haustoria?

Structures that allow fungi to extract or exchange nutrients with plants by penetrating host cells.

What are mycorrhizae

Symbiotic associations between fungi and plant roots that enhance nutrient exchange.

Where do mycorrhizae grow ?

into the extracellular spaces of the root or extend hyphae directly through the cell walls of the root.

How do plants rely on fungi?

the mycorrhizae allow the plant to obtain phosphate ions and minerals.

What is a lichen?

a symbiotic association between a photosynthetic protist (algae) or bacteria and a fungus.

How do the parts of the lichen interact?

The algae provide carbon compounds, bacteria also provide organic nitrogen, and fungi provide the environment for growth.

Where do the algae/bacteria occupy in a lichen?

underneath the fungal hyphae

How do fungi reproduce?

with spores, both asexually (more common) and sexually

Which is more common in a fungi life cycle: haploid or diploid?

haploid!

What is plasmogamy?

the union of cytoplasm from two parent mycelia.

What is karyogamy?

the fusion of nuclei to produce diploid cells.

What is a heterokaryon?

a fungal mycelium that contains genetically different nuclei within the same cytoplasm.

What is a dikaryon?

A type of fungal mycelium characterized by containing two genetically distinct nuclei within a single cell, allowing for dual genetic material.

How do dikaryon and heterokaryon differ?

blah

What are molds?

fungi that produce visible mycelia and produce haploid spores through mitosis.

What is a yeast?

asexual, unicellular fungi that reproduce with simple cell division and buds

What is a chytrid?

widespread in lakes and soils and include decomposers and parasites.