prokaryotes that are not archaebacteria

ex: blue-green algae, Escherichia coli

·         single celled and simple multicellular organisms having nuclei

·         includes protozoa, algae, water molds, and slime molds

·         where everything that doesn’t fit another eukaryotic kingdom is put

·         organisms with cell walls consisting of chitin

·         most are multicellular

·         includes molds and yeasts

·         complex multicellular organisms having tissues and organs

·         plant cells have walls containing cellulose

·         most (but not all) contain chlorophyll in chloroplasts, and carry on the process of photosynthesis.

·         complex multicellular organisms that must eat other organisms for nourishment

·         typically contain cells lacking walls, and have organs and organ systems

·         most (but not all) forms are motile

§  zygote immediately undergoes meiosis

§  diploid zygote never undergoes mitosis; mitosis only in haploid cells, making haploid individuals

§  found in many protists

§  meiosis produces gametes that never undergo mitosis

§  zygote undergoes mitosis, making diploid individuals

§  found in most animals

§  zygote undergoes mitosis, making diploid individuals

§  some diploid cells undergo meiosis to make haploid spores (sporic meiosis)

§  mitosis in haploid spores, making haploid individuals

§  some spores develop into gametes, which undergo syngamy to make a diploid zygote

§  thus, two bodies in one life cycle – two instances of mitosis in one life cycle

homo - genus

sapiens - specific epithet

basic unit of classification or taxonomy

·         if sexual, a group of organisms that can interbreed and produce fertile offspring

·         if asexual, grouped based on similarities (DNA sequence is best)

·         about 1.8 million living species have been described, likely millions more

·         the Genus name is always capitalized, and the specific epithet is never capitalized.

·         the Genus and specific epithet are always together, and italicized (or underlined).

·         example: Homo sapiens or Homo sapiens

one or more populations whose members are capable of interbreeding and producing fertile offspring, and whose members are reproductively isolated from other such groups

a single line of descent (lineage) that maintains its distinctive identity from other lineages; works for all species, but it can be hard to clearly define “distinctive identity”

1. Excavata
2. Discicristata
3. Alveolata
4. Stramenopila
5. Rhizaria
6. Archaeplastida
7. Amoebozoa
8. Opisthokonta

1.        “double cell” structure

2.        have two equal-sized nuclei and multiple flagella

3.        modified mitochondria called mitosomes

4.        includes Giardia lamblia, the organism that causes “hiker’s diarrhea” or giardiasis

·         infects humans and some other animals; found across U.S. in most freshwater

·         causes nausea, cramps, diarrhea

1.        modified mitochondria called hydrogenosomes that make hydrogen gas

2.        includes Trichomanas vaginalis, a sexually transmitted parasite in humans

·         disease called trichomoniasis or “trich” infections

·         over 7 million new infections each year in the U.S. alone, although many show no symptoms

·         symptoms are discolored discharges from vagina or penis and painful urination and intercourse

·         most infected men and about 20% of infected women have no obvious symptoms

A.      synapomorphy: mitochondria with distinctive disc-shaped cristae

B.       largest group is the phylum Euglenozoa

euglenids and kinetoplastids

 the largest group within this clade

crystalline or spiral rod in flagella

·         some photosynthetic (using chlorophylls a and b, like green algae and plants), but some are not

·         ancestors of photosynthetic forms likely got their chloroplasts from green algae that they ate (“secondary endosymbiosis”) – in other words, this is NOT a synapomorphy that defines a clade

·         some are facultative heterotrophs, photosynthetic forms that can switch to being heterotrophs if kept in the dark, and switch back to autotrophs if given enough light

·         characterized by having a helical, flexible protein coat called a pellicle on the outside of cell

·         only asexual reproduction

·         important members of many freshwater food chains

·         example: Euglena.

·         single, large mitochondrion that has an organized mass of DNA called a kinetoplast

·         include trypanosomes – a group that includes some important parasites of humans and domestic animals

§         African sleeping sickness: caused by Trypanosoma

i.       carried to new host by biting fly (tsetse fly)

ii.     Affects cattle and prevents livestock culture in large area of Africa.

§         Leishmaniasis (caused by Leishmania)

i.       carried to new host by biting fly (sand fly) in tropical areas

ii.     causes sores and erosion of skin (4 million people/yr)

A.      synapomorphy: sac-like “alveoli” that form a continuous layer just under the plasma membrane

B.       3 major groups

1.        Phylum Dinoflagellata (dinoflagellates)

2.        Phylum Apicomplexa (sporozoans)

3.        Phylum Ciliophora (ciliates)

1.        unicellular, mostly marine; 2100 species known

2.        usually have 2 flagella

3.        most have chlorophylls a and c, so chloroplasts are like those of diatoms, golden algae, and brown algae, more likely due to secondary endosymbiosis

4.        have an exoskeleton made up of plates of cellulose

5.        reproduce mostly by asexual reproduction (sex rare but it does occur)

·         zooxanthellae: symbionts (live in mutually beneficial relationship) in other organisms (jellyfish, sea anemones, mollusks, corals)

§         zooxanthellae in corals (up to 30,000 cells per cubic mm or coral tissue) do photosynthesis and make carbon products absorbed by coral

§         help make coral reefs one of most productive habitats on Earth

§         can actually leave the corals and live on their own – probably in response to pollution

§         many of the world’s coral reefs are bleaching (dinoflagellates are leaving), killing the coral

·         bioluminescent: many planktonic dinoflagellates emit light when disturbed

§         creates sparkling waves and glowing wakes of ships at night

§         Why do this? Perhaps to attract predatory fish to eat the predators of the dinoflagellates!

·         predatory dinoflagellates

§         some generate toxins that they use to kill marine life

§         example, Pfiesteria piscicida: stuns fish with toxin and feeds on body fluids

§         red tides: population explosions (“blooms”) that can color the water with pigmented dinoflagellate cells; red tides kill marine life due to the high concentration of toxins from the dinoflagellates

§         some dinoflagellates cause disease in humans who are exposed to them in high levels

§         hog farm manure lagoons in NC appear to be a breeding ground for deadly dinoflagellates that cause freshwater fish kills and human disease

1.        unicellular

2.        nonmotile, spore-forming parasites of animals (their spores are infective bodies used to reach new hosts)

3.         ~3900 species described

4.        cell structure unique: one end (apex) of cell has dense concentration of organelles

5.        complex life cycle, with both sexual and asexual phases – alternation of generations

6.        famous example: Plasmodium - malaria

1.        unicellular (but some big and internally complex)

2.        ~8000 species known

3.        most with many cilia

4.        outer covering (called pellicle) of tough protein material

5.        form vacuoles for ingesting food and regulating water balance

6.        two types of nuclei: macronucleus (large) and micronucleus (small)

·         micronuclei – diploid chromosomes – for sexual reproduction

·         macronuclei – derived from micronuclei; multiple copies of small strands of DNA (sometimes one gene) for metabolic, synthetic, and developmental functions

7.        unusual sexual reproduction: conjugation – two different mating types; partners exchange haploid micronuclei that can will then fuse to make diploid micronuclei

8.        famous example: Paramecium

A.      synapomorphy: normally two flagella when present, with hairlike projections on one of them

B.       4 major groups

1.        Phylum Oomycota (oomycetes)

2.        Phylum Bacillariophyta (diatoms)

3.        Phylum Chrysophyta (golden algae)

4.        Phylum Phaeophyta (brown algae)

1.        ~580 species

2.        parasites or saprobes (feed on dead organic matter)

3.        cellulose or cellulose-like cell wall (no chitin)

4.        can form filamentous structures (threadlike cells) called hyphae

5.        asexual and sexual reproduction

·         sexual via gametic meiosis; zygote becomes thick-walled oospore

·         make asexual spores called mitospores by mitosis

§         as with all spores, one can form a new organism without joining with another cell

§         swimming mitospores are called a zoospores

6.        importance:

·         some cause diseases of plants or fish, such as potato blight and downy mildew

1.        have chlorophylls a and c, so chloroplasts are like those of golden algae and brown algae

2.        make chrysolaminarin, a unique carbohydrate used for energy storage (also made by golden algae)

3.        unicellular

4.        more than 11,500 living species known

5.        occur in plankton

6.        lack flagella

7.        have a cell wall made up of double shells of silica that fit together like a box and lid

8.        diatom shells have intricate designs

9.        mostly asexual reproduction, but can undergo gametic meiosis (diatoms are usually diploid for most of their life cycle)

10.     importance:

·         “grass of the sea” – abundant members of plankton; perform a large % of the photosynthesis done in oceans

·         fossil deposits of cell walls called “diatomaceous earth”, which is mined and used for pest control (applied to insects, gets in appendages and grinds them to death), reflective paints, filters