CH 12 - Eukaryotes

Thallus

Fungal body

Thallus consists of

Hyphae

Mass of hyphae is

Mycelium

Fungus hyphae types

• vegetation hyphae - grow nutrients

• Aerial hyphae - reproduction

Different types of yeasts

• Fission yeasts - divide symmetrically

• Budding yeasts - divide asymmetrically

Types of reproduction

• asexual

• Sexual

Asexual reproduction

Produces spores NOT endospores

Sexual reproduction

• Produce spores from nuclei of two opposite mating strains of same species of fungus

• Less frequent than asexual reproduction

2 types of asexual spores

• conidia or conidiospores - from conidiophore

• Sporangiospore - from sporangium

Zygospore

Created from a fusion of haploid cells (black mold)

Ascospore

Formed in a sac (ascus)

Basidiospore

Found externally on a pedestal (bastidium)

Nutritional adaptations of fungi

• Chemoheterotroph

• Can adapt to environments that are hostile to bacteria

Types of environments that are hostile to bacteria

• low pH

• Low moisture

• Less nutrients

• High osmotic pressure

• Metabolizing complex compounds

Impacts of fungi to humans an environment

• decomposition

• Symbioses

• Food and biotechnology

• Diseases

Mycosis

Fungal infection

Mycosis is classified into five groups according to

Tissue involvement and mode of entry

5 groups of Mycosis

• systemic

• Subcutaneous

• Cutaneous

• Superficial

• Opportunistic

Systemic Mycoses

• deep within the body

• Caused by fungi in soil

• Transmission via inhalation of spores

Subcutaneous mycoses

• beneath the skin

• Infection via direct implantation of spores or mycelia’s fragments

• Enters in the wound

Cutaneous mycoses

• affects hair, skin, and nails

• Transmitted from human to human

Superficial mycoses

• Localized

  • Hair shafts

  • Surface epidermal cells

Opportunistic mycoses

Caused by normal microbiota or environmental fungi

Lichens

Mutualistic combination of alga and fungus

Alga function in lichens

Produces and secretes carbohydrates

Fungus function in lichens

Provides support, nutrients, protection

Three types of lichens

• fruticose

• Foliose

• Crustose

Selective phyla of algae

• brown algae

• Red algae

• Green algae

• Diatoms

• Dinoflagellate

• Water molds

Phaeophyta

• brown algae

• Cellulose and alginic acid cell wall

• Multicellular

• Harvested for food

Algin

Gelling products

Rhodophyta

• red algae

• Cellulose cell walls

• Multicellular

• Harvested for agar and carrageenan

Chlorophyta

• green algae

• Cellulose cell walls

• Unicellular/multicellular

• Gave rise to plants!

Diatoms

• pectin and silica cell walls

• Unicellular

• Produces dominic acid

  • Toxin causes diarrhea and memory loss

Dinoflagellates

• cellulose in plasma membrane

• Unicellular

• Some produce neurotoxins

  • Causes paralytic shellfish poisoning

• Creates red tide

Water molds

• cellulose cell walls

• Multicellular

• Chemoheterotroph

• Produce zoospores

Oomycota

• decomposers and plant parasites

Phytophthora infestans

Responsible for Irish potato blight

P cinnamoni

Infects eucalyptus

P. Ramorum

Causes sudden oak death

Role of algae in nature

• fix CO2 in organic molecules

• Produces 80% of earth’s O2

• Oil production

• Symbionts of animals

• Algal blooms

Algal blooms

• Increases in planktonic algae

  • Results in toxin release

  • Dies and can consume oxygen

Medically important Protozoa

• Feeding grooves

• Amebae

• Apicomplexa

• Ciliates

Types of feeding grooves (excavata)

• diplomonads

• Parabasalids

• Euglenozoa

Apicomplexa

• nonmotile

• Obligate intracellular parasites

• Complex life cycles (transmission between several hosts)

Sporozoite

Infective stage of plasmodium vivax

Merozoite

Offspring

Intermediate host

Host in which the parasite undergoes asexual reproduction

Definitive host

Host in which the parasite undergoes sexual reproduction

Kingdom of helminths

Animalia

Phylums of helminths

• Platyhelminthes (flat worms)

• Nematoda (roundworms)

Classes of helminths/platyhelminthes

• trematodes (flukes)

• Cestodes (tapeworms)

Parasitic helminths characteristics

can live inside their hosts

• reduced digestive system

• Reduced nervous system

• Reduced locomotion

• Complex reproduction

Life cycle of helminths

Egg —> larvae —> adult

Monoecious

Male and female reproductive systems in one animal

Dioecious

Separate male and female