5 Kingdoms of Life:

1. 5 Kingdoms of Life:

2. The Kingdoms…

3. Virusus: • viruses are composed of nucleic acidsenclosed in a protein coat called a capsid and are smaller than the smallest bacterium. • Most biologists consider viruses to be nonliving because they don’t respirate, grow, or develop, and thus aren’t in a kingdom of life. • Viruses can replicate themselves, but only with the help of living cells called host cells. • Viruses cause many diseases in people, animals, and plants. • Before a virus can enter a host cell it must first recognize and attach to a receptor siteon the plasma membrane. • The RNA virus with the most complex replication cycle is the retrovirus. • Retroviruses use an enzyme called reverse transcriptaseto make DNA from its RNA once inside its host cell.

4. Monerans: • Bacteria are the oldest and most abundantorganisms. • They can be found everywhere. • Unique in that they are prokaryotic. • Most monerans have a cellwall. • Classified into two categories: archaebacteriaand eubacteria. • Antibiotics kill bacteria, but some bacteria are resistant to some antibiotics.

5. Most archaebacteria live in extreme environments such as in the digestive tract of mammals or cracks deep in the ocean floor. Eubacteria are mostly heterotrophic. The autotrophic ones are either photosynthetic or chemosynthetic. Many monerans can move, some having flagella. Monerans reproduceasexuallythrough a process called binary fission. Some bacteria cells can split every 20 min. under ideal conditions- leading to exponential growth in population.

6. Protists • Kingdom Protista contains mostdiversity among its organisms. • All protists are eukaryotesie. Most metabolic processes occurs inside their membrane-bound organelles. • Animal-like heterotrophic protists are called protozoa, which areunicellular. • Plant-like autotrophic protozoa are called algae. • Some protists cause diseases in otherorganisms. • Fungus-likeprotists decompose dead organisms, but are mobile during past of their life, and don’t have chitincell walls. • Reproduction can be sexual or asexual.

7. Protozoa • Amoebas change their shape to move and capture its food using bodily extensions called pseudopia. • Sporozoansare protozoa that are immobile, parasitic and reproduce by releasing spores (ex: Genus plasmodium cause malaria) • Flagellates are protozoans that use flagella to move and capture food. Some of which are parasites that cause diseases in animals. • Some protozoans have thousands of tiny hair-like ciliato move around in fluids and are called ciliates(ex: paramecium)

8. Plant-like Protists • Algae come in many different colors, and as such many are classified according to their color. • Photosynthesizing unicellular algae are called phytoplankton and are major producersof nutrientsand oxygenin aquatic ecosystems. • Multicellular algae have no roots, stems, or leaves separating them from the plant kingdom. • Euglenoids are aquatic protists with both plant and animal characteristics (ex: no cell wall, have chlorophyll, but are heterotrophs when light is not available)

9. Diatoms are golden-yellow unicellular photosynthetic organisms with shells composed of silica. The food they synthesize is made of oils rather than starch. • Dino flagellateshave thick, cellulose plates, chlorophyll, yellow-red pigments and resemble helmets and suits of armor. They have two flagella and slowly spin. Some produce toxins for defense. • Among the protists are 4000 species of red algae, approx. 1500 species of brown algae, and over 7000 green algae. All are multicellular and some formcolonies. Red and brown algae live in or near bodies of water. Green algae can live in water, or trees, in snow, or even in the fur of sloths.

10. Fungi-like Protists: • Among the protists are slime molds, water molds, and downy mildews, all having fungus like features ( like cool, shady, moist environments and feed on decaying plant material) • Slime moldsare beautifully coloredorganisms that live in cool, moist, low-lit places, where they grow on decaying organic matter. • Like fungi, slime molds make spores to reproduce.

11. Plasmodial slime moldsform a mass of cytoplasm full of diploid nuclei called a plasmodium. This plasmodium creeps like an amoebaover its food source. • Cellular slime moldsare consisted of haploid, amoeba-like cellsthat combine with others to form a spore-filled capsule on a stalkfor reproduction. • Water moldsappear as fuzzy white growthson decaying matter, but unlike fungi, they produce flagellated reproductive cells. • One downy mildew is phytophthorainfestans which kills potato plants in Ireland.

12. Fungi: • Fungi are everywhere: in the air, water, damp basement walls, gardens, on foods, in between people’s toes (athlete’s foot). • They vary greatly in size, form and color. • Fungi used to be classified in the plant kingdom because they grow anchored to their food and have cell walls. • However, biologists later realized that they belong to their own kingdom.

13. A few fungi are unicellular (ex. yeast) but most are multicellular. • There are 3 basic structural units in multicellular fungi: • 1) threadlike filaments called hyphae which develop from spores • 2) extensive network of filaments called mycelium • 3) unlike plants which have cellulose, fungi have cell walls made of chitin • Fungi can cause food to spoil, some cause diseases, others are poisonous. • Without fungi, the Earth would be littered with complex organic wastes, in a form other organisms cannot retrieve energy from. • Fungi aren’t heterotrophs, so they use a process called extracellular digestionto obtain nutrients, where the food is digested outside a fungus’s cells by the secretion of enzymes then absorbed. • Fungi reproduce sexually or asexually by fragmentation, budding, or spores.