LIFE SCIENCE Chapter 7 Notes: Compare Against What You Have in Your Spiral Notebook!

LIFE SCIENCE Chapter 7 Notes: Compare against what you have in your spiral notebook!

KINGDOM: Protists Section One

I. Two COMMON characteristics all share

A. All eukaryotes (have cells with nuclei, like YOU do)

B. All live MOIST surroundings

II. “Junk drawer” kingdom – DIVERSE (very different from each other)

A.Most unicellular (made up of ONLY one cell) like pretty diatoms

B.Some multicellular (many cells) – like giant kelp

C. Some heterotrophs (get food from an other source), some are autotrophs (make own food – self feeders), some BOTH

III.THREE main groups

A.PROTOZOANS (animal-like protists) –animal-like because all are heterotrophs and most can move from place to place to get food -different from animals because they are UNICELLULAR

1. Sarcodines – have a “false foot” or pseudopod to move and to trap food – example is ameba (no definite shape because cell membrane is VERY thin) – have CONTRACTILE

VACUOLE to expel excess water that passes in so ameba doesn’t explode or burst

2. Ciliates – protozoans with hairlike projections called cilia – use these like tiny oars to move and also sweep food into oral groove (like a mouth) – example is paramecium

3.Zooflagellates – protozoans with one to eight whip-like structures called flagella to help them move – example is Giardia

a. Symbiosis – interaction between two species where at least oneof the species benefits

* Mutualism –type of symbiosis or interaction between two species where BOTH benefit (example is zooflagellates that live in termites)

* Parasitism –type of symbiosis where host organism is harmed (like Giardia, which you get from drinking bad water –attaches to your intestines and makes you very sick – don’t drink water from streams or rivers when camping!)

* Commensalism – a type of symbiosis where one species benefits and the other is neither harmed nor help (unaffected)

4.Sporozoans – other protozoans – ALL are parasites –move in different ways (some have flagella, some depend on host to move, and some slide on layer of slime) - can have more than one host, example is sporozoan that causes malaria, a blood disease –use both mosquitoes and people as hosts

B. Funguslikeprotists –LIKE fungi because heterotrophs, have cell walls, and use spores (tiny cells able to grow into new organism) to reproduce – UNLIKE fungibecause all able to moveat some point in life. Three types: WATER MOLDS, DOWNY MOLDS (both look like tiny fuzzy threads – like water mold parasite on the fish), and SLIME MOLDS (beautiful colors, grow in moist soil or on decaying plants and trees – move using pseudopods)

C. Plantlike protists – common name ALGAE –very diverse but ALL are AUTOTROPHS (make their own food) – just like plants

1. Examples:EUGLENOIDS or euglena (fresh water, green, unicellular – can be autotrophs OR heterotrophs);DINOFLAGELLATES (unicellular, many different colors, glow in the dark on the ocean’s surface, stiff hard plates covering them);DIATOMS (unicellular with beautiful glass-like cell walls – look like stained glass – ground up in toothpaste, cleaners,

DE for pool filters, and insecticides); GREEN ALGAE (freshwater or saltwater, most unicellular);RED ALGAE (multicellular seaweeds, nutritious – especially eaten in Asian cultures – red because can absorb small amount of sunlight deep in the ocean); BROWNALGAE (what we typically call seaweed –example is giant kelp, form underwater “forests,”

can be 300 feet tall, provide a home formany ocean animals)

2. Algae contain many types of PIGMENTS – chemicals that produce color (green, yellow, red, brown, orange, or black)

SECTION TWO: ALGAL BLOOMS

RAPID growth of algae called algal bloom (not good) – can happen in freshwater or saltwater

SALTWATER ALGAL BLOOMS typically called RED TIDES (often have red pigments but CAN be green, brown, colorless – depends on species of algae that blooms) – happen more now than 20 years ago - can be from excess nutrients in water, climate change (warmer ocean temperatures), or change in ocean currents bringing up nutrients from cold deep water. Can release toxins that kill even large humpback whales and cause beaches to close – fish and people can die from eating shellfish that feed on these algae

FRESHWATER ALGAL BLOOMS – can cause EUTROPHICATION: nutrients build up, cause algae to bloom, blocks sunlight so plants die, get more bacteria as decomposers because of dead plants, bacteria use up oxygen, fish die. Eutrophication can be natural over tens of thousands of years (ponds or lakes turn into meadows), but people speed it up by dumping fertilizers and sewage into freshwater

KINGDOM: Fungi Section Three

I. Four COMMON characteristics MOST of them share:

A. EUKARYOTES (have cells with nuclei, like YOU do)

B. Live inMOIST surroundings

C.In regard to food, they are HETEROTROPHS (get their food from OTHER sources)

D.Use SPORES to reproduce. Most can reproduce EITHER sexually OR asexually.

E.MOST (except yeast) are MULTICELLULAR (have many cells)

II. Structure

A. HYPHAE: branching, threadlike tubes make up the bodies of multicellular fungi (EXCEPT yeast - unicellular)

1. Substances move THROUGHthese threadlike tubes

2.Some hyphae LOOSELY-tangled - like fuzzy-looking bread mold

3. Other fungi, like mushrooms - TIGHTLY-packedhyphae

B.Hyphae above ground in mushroom stalk (or stem, sometimes called stipe) and cap - so tightly packed together they look SOLID

C.HYPHAE underground form loose maze in soil (look like roots, but NOT roots) -

underground network of hyphae called MYCELIUM or MYCELIA (this is not in your

book)

III.Getting food

A.ABSORB food through hyphae that grow into food source

B.Grows hyphae INTO food source, OOZES out digestive chemicals into food, digestive chemicals BREAK DOWN food into SMALL substances - can then be

ABSORBED through hyphae

IV.Reproduction

A.Produce SPORES but only a FEW of thousands that get released will end up in favorable conditions - grow into new fungi

B. Spores - lightweight, protective coat, easily carried by wind or water

C.Spores produced in part of fungi called the FRUITING BODY

D.When GOOD conditions (enough moisture and food), fungi reproduce ASEXUALLY -

grow fruiting bodies that release THOUSANDS of spores

1. BUDDING is a kind of ASEXUAL reproduction that unicellular yeast goes through:

small yeast cell grows from body of large, well-fed parent yeast cell

E.When conditions NOT good, fungi can reproduce SEXUALLY by having

hyphae of two fungi GROW TOGETHER and exchange genetic material. Spore-

producing structure (fruiting body) then grows out of two JOINED hyphae

V.Classification of fungi (based mainly on the shape of their spore-producing structures)

A.THREADLIKE:About 600 different species - all produce spores in threadlike structures Examples - BREAD MOLDS (such as Rhizopus)

B.SAC Fungi: About 30,000 species - produce spores in structures that look like SACKS

Examples: YEAST, BIRD’S NEST FUNGI, TRUFFLES, and fungi that cause DUTCH ELM DISEASE

C.CLUB Fungi: About 25,000 species (including MUSHROOMS) - grow spores in structures

that look like clubs. Other examples: PUFFBALLS and BRACKET FUNGI (look like shelves)

D.IMPERFECT Fungi: About 25,000 species - do NOT reproduce sexually. Most well-known

example: Penicillium, used as ANTIBIOTIC

VI.Fungi and the living world

A. HELPS

1.Decomposers (same job as some bacteria….nature’s recyclers of chemicals)

2.Provide food: yeast in breads and wine, some cheeses (blue cheese), mushrooms (NEVER

pick wild mushrooms)

3.Fight disease (penicillin from Penicillium) – Alexander Fleming, 1928, by “accident”

4.Symbiosis (fungus and plant ROOT association) – the mycelia (hyphae) of the fungus

spread out searching for water and nutrients from soil –share that with plants,

and plants share food they make (as AUTOTROPHS) with fungi

TERM: FAIRY RING – when fruiting bodies of mushrooms (the caps) emerge in almost

perfect circle because sharing the same underground hyphae (mycelia). Watch our football field. Question: Why does the grass growing around the mushrooms look greener than the other grass?

B.HARMFUL - cause diseases

1. Plants: corn smut, wheat rust (both caused by types of club fungi) and Dutch elm

disease (trees) – caused by a sac fungus

2. Humans: athlete’s foot, ringworm, some types of pneumonia

VII.LICHENS are fungus that live together (MUTUALISM) with either algae or autotrophic

bacteria….grow on tree bark or rocks – look like crusty patches

1. Fungus gets food from algae (plant-like protists that are

autotrophs) or autotrophic bacteria - algae or bacteria get water and minerals from fungi

2. Often called PIONEER ORGANISMS because the first to appear after forest fires,

volcanoes, or rock slides. Since very sensitive to pollution, scientists monitor

lichens to measure air quality