bio 3 exam

Protist

Protist

Any organisms that are eukaryotic (have a nucleus) but are not animals, plants, or fungi.

Animal-like protists

Hunt and move around for prey

Fungi-like protists:

live as heterotrophs and form sheet-like colonies of cells like a fungus

Plant-like protists

they are multicellular and photosynthetic like a plant

Single vs multi-cellular

• Diatoms are single-celled and have a silica-based cell wall

• Algae are multicellular that form large kelp forests underwater

Terrestrial vs. aquatic

• Many live in soil, on trees & rocks, etc. love damp environments

• Many live in water, including diatoms, water molds, green algae,& red algae

Motile vs. stationary

1. Most diatoms are stationary due to their thick silica cell wall

2. Dinoflagellates have flagella tails that can propel them through water

Sexual vs. asexual

1. Many protists reproduce asexually through binary fission (cell division)

2. Some reproduce sexually: 2 individuals contribute genetic material to offspring that is genetically different from both parents. (no sex organs involved)

Autotropic vs. Heterotrophic

1. Protists that undergo photosynthesis are autotrophic (self-feeding) & are generally called algae

2. Heterotrophic protists get nutrients from their surroundings by either: absorbing nutrients directly through cell membranes or ingesting food

Protists that ingest food are predators

• Use extensions of the cell membrane called pseudopods to surround & engulf prey

• Other predatory protists create tine currents that sweep food particles into the mouth-like openings in the cell.

Protists that absorb nutrients directly from the surrounding environment

1. Free-living types in the soil that decompose organic dead matter

2. Parasites that live inside the bodies of other organisms, sometimes harming the host

Protists & other organisms/environment positive 1

Photosynthesis

• Capture sunlight, turning it into fuel for all living things

• Produce oxygen, allowing us to continue breathing

• Pull carbon dioxide from the air, reducing dangerously high levels in the atmosphere

Protists & other organisms/environment: positive 2

Food sources

• Protists (plankton) are the most important organism in the ocean food chain

Protists & other organisms/environment: positive 3

Commercial uses

• Agar is a gelatinous substance derived from algae & is used as a: vegetarian substitute for gelatin

Protists & other organisms/environment: negative

Some protists act as pathogens, causing illness & disease

• Parasitic protists cause some common and sometimes deadly ailments in humans

• “light blight” caused the Irish potato famine of 1840

• “downy mildew” is a parasitic water mold that can destroy crops like grapes

• Marine protists that release toxins that can accumulate to harmful levels in coastal areas “red tide”

Fungi characteristics

• Heterotrophic -Secrete enzymes to absorb nutrients

• Multicellular

• Mycelium body structure

  • Reproduce using spores

  • Hyphae- threadlike filaments

  • Septa- divide cells into partitions and pores to allow nutrients to pass through each cell

• Chitin- in cell walls. It is tough and flexible

• Fruiting bodies = reproductive spore-producing structures such as mushrooms, puffballs, or truffles

Endophytes

live with plants and provide benefits to the plant

Mycorrhizae

roots of plants

Lichens

live on or with protists or bacteria

Fungi & other organisms: the good 1

Provide antibiotics

• Not all but many antibiotics are derived from fungi

• The 1st antibiotic discovered, penicillin, is produced by a mold

• Other medications are derived from fungi as well (cyclosporin)

Fungi & other organisms: the good 2

• Some fungi provide food

  1. Mushrooms, such as morels and truffles, are eaten by many animals

  2. Certain molds impart flavor to some of the world’s most famous cheeses

Fungi & other organisms: the good 3

• Yeast is useful in baking and brewing

  1. Wine is produced when yeasts ferment fruit sugars

  2. Beer is derived when yeasts ferment sugars in germinating grains (barley)

  3. Bread rises when yeasts ferment sugar that has been added to bread dough

Fungi & other organisms: the good 4

• Most fungi are important decomposers

  1. Fungal Saprophytes feed on dead organisms

     1. Secrete substances that digest the tissues of dead organisms, liberating nutrients that can be reused by plants

     2. Important for recycling minerals, nutrients, & energy on earth

Fungi & other organisms: the bad 1

• Parasitic

  1. Fungal parasites cause the majority of plant diseases

  2. Rusts & smuts = parasites that cause considerable damage to grain crops

Fungi & other organisms: the bad 2

• Mold and mildew

  1. Some molds & mildews cause wooden structures to rot

  2. Some damaged cotton and wool fabrics

Fungi & other organisms: the bad 3

• Poisonous

  1. Claviceps purpurea produces several toxins. It infects rye plants and causes a disease called ergot.

  2. Ergot symptoms= vomiting twitching hallucinations, & death.

Fungi & other organisms: the bad 4

• Pathogenic

  1. Jock itch is caused by fungi that affect the skin

Plant characteristics 1

• Plants exist nearly everywhere

  1. Form the basis for complex food webs & provide diverse habits for all other organisms

Plant characteristics 2

1. Plants are autotrophic

   1. Self-feeding through photosynthesis

Plant characteristics 3

Plants are multicellular

Plant characteristics 4

Plants are immobile

Plant characteristics 5

• Most plants reproduce sexually (& some asexually)

  1. Some plants can make offshoots, giving rise to identical offspring: asexual reproduction

  2. Most plants reproduce sexually ( sperm and egg) Alternation of generations (sporophyte, gametophyte, embryo, haploid, diploid…)

A full plant creates (diploid)

sporophyte

A sporophyte (haploid) produces

spores

Spores grow into

Gametophytes (not a full plant haploid)

Gametophytes produce

gametes (egg and sperm) haploid

A fertilized egg turns into

an embryo (diploid)

The embryo turns into

A full plant

Plants (positive 1)

• Provides food for animals, fungi, & other heterotrophic organisms

  1. Energy moves 1-way coming from the sun to the earth into plants

  2. Organisms eat plants and other organisms to stay alive

Plants (positive 2)

maintain the atmosphere

1. Through the process of photosynthesis. They pull CO2 from the atmosphere and release O2

Plants (positive 3)

build & maintain the soil

1. Dead plant material is decomposed into organic matter, adding nutrients that soil makes more fertile.

2. They hold the soil together preventing erosion

Plants (positive 4)

Keep water in ecosystems

1. They absorb stored water from the soil & release it slowly

Plants (positive 5)

provide shelter and homes for organisms

Plants (positive 6)

provide important medicines

1. Aspirin

2. Taxol

Plants (positive 7)

provide useful materials for fuel & other commercial goods

1. Fuel, twine, canvas, clothing, pigments, alcohol, cleaners, oils, cosmetics

Nonvascular plants

• No way to conduct water around the plant

• No seeds: sperm & egg must meet in the water

• MUST be around water

Vascular plants

• Have tube-like cells to spread water

• Provide support & transport water

• Allows for larger size and can move away from water

Vascular seedless

• Plants have no seeds, so they still require sperm & egg to meet in the water

• Some stay near water to continue reproduction

Vascular seeded

• Pollen= tiny grains for reproduction

  • Dispersed by wind or pollinators

  • Eliminates the need for sperm to swim to the egg, so they can live and reproduce on dry land

• Seeds protect the embryo as it grows and provide it with nourishment

Gymnosperms

vascular seeded plants that do NOT have flowers or fruits

Angiosperms

vascular seeded plants with flowers & fruits

• Most Diverse & widespread of all plants

Flowers

Reproductive structures in which gametophytes are formed

Fruits

Contain developing seeds

How are seeds spread around

• Edible fruits entice animals to eat them: seeds pass through the digestive tract unharmed

• Burr fruits cling to animal fur

• Winged fruits are carried through the air