Studied by 13 peopleWhat essential services do fungi provide for ecosystems?
decomposition
recycling of nutrients
soil maintenance
Characteristics of Fungi
Eukaryotic
Heterotrophic
Multi-cellular (most)
Typically not motile
Have an alternation of generations (can reproduce sexually & asexually)
Cells have cell walls made of chitin
Most are terrestrial
Feed via extracellular digestion
Fruiting Structure (Sporocarp)
The above ground structure that houses the spores
Called the mushroom cap
On the underside of the cap, spore-producing structures called basidia form on the mushroom’s gills
Basidia
Spore-producing structures found on the underside of the mushroom cap
Body (structure of a club fungus)
The main structure of the fungus is located below ground.
The body is a mesh-like structure, made up of a branching network of filaments that are collectively called mycelium.
The individual mycelium filaments are called hyphae (singular: hypha) The hyphae are microscopically thin. They consist of long tubes of cytoplasm containing many nuclei. The cell wall is composed of chitin
The hyphae tubes are sometimes separated into cell-like compartments by cell walls called septa (singular: septum) The walls are not solid and contain large pores and the cytoplasm is therefore continuous from end to end
Mycelium
The body of a club fungus made up of a branching network of filaments
Hyphae
The individual mycelium filaments
Consist of long tubes of cytoplasm containing many nuclei. The cell wall is composed of chitin
Hyphae tubes are sometimes separated into cell-like compartments by cell walls called septa. Cells walls are not solid and contain large pores → cytoplasm is continuous
Fungus Life Cycle
Mycelium of the body pushes above the ground to form the fruiting body. The mycelium fibres run up through the stem into the cap.
Spores are released. Each spore that is released is haploid (containing only one copy of each chromosome).
Spores grow and produce hyphae with one nucleus.
When two hyphae come in contact, two of their cells can fuse, forming a dikaryotic cell (a cell with two separate nuclei – the nuclei do not join)
The dikaryotic hyphae grows into mycelium which produces the mushroom cap when it is mature. Inside the basidia gills, the two haploid nuclei fuse forming a zygote. The zygote divides and produces 4 haploid spores.
Haploid
Contains only one copy of each chromosome
Dikaryotic cell
A cell with two separate nuclei
Symbiotic Relationships
Fungi + Trees (any plant)
Fungi increases the surface area of the trees roots → tree is able to get more food and water
The tree produces food in the leaves and sends it towards the roots → fungi can use as food
Symbiotic Relationships
Fungi + Cyanobacteria = Lichens
The fungus provides structural support, carbon dioxide, and water to the cyanobacteria
The cyanobacterium shares its carbohydrates with the fungus
Zygospore Fungi (Zygomycota)
Reproduce asexually & sexually
during sexual reproduction produce zygospores
Ex: Bread moulds
Club Fungi (Basidiomycota)
Have short lived reproductive structures called basidiocarps (fruiting bodies) that form basidiospores
Reproduce asexually by either budding or asexual spore formation
Ex: Mushrooms, bracket, fungi, puffballs
Sac Fungi (Ascomycota)
Reproduce both sexually (forms sacs) and asexually (produces spores)
Identified by fingerlike sacs called asci which form during sexual reproduction.
In asexual reproduction, spores are produced at the tip of hyphae
Ex: Mildews, morels, truffles, yeast
Imperfect Fungi
Imperfect because they do not have a sexual phase
Ex: Penicillium makes the drug penicillin, P. roquefort makes blue cheese, deuteromycetes used to make soya sauce, cyclosporine is a drug used in transplant patients
Characteristics of Animals
Eukaryotic
Cells have no cell wall
Multicellular
Heterotrophs that ingest food
Mobile at some point in their life cycle
Form a hollow ball of cells called a blastula during the embryological development
Classifying Animals
Body Organization
Specialized cells are organized into tissues, organs, and organ systems
The development of nerves is a key early innovation important for coordinating movements and sensing changes in the environment.
Members of the Porifera phylum (sponges) are the only animals that lack a nervous system and other tissue types.
Classifying Animals
Body (Germ) Layers
There are three different layers of cells in a developing embryo that give rise to the specialized tissues:
Ectoderm (outer layer e.g. skin, nervous system)
Endoderm (inner layer e.g. lining of body cavity)
Mesoderm (middle layer e.g. circulatory, reproductive, muscular systems)
Ectoderm
Outer layer (e.g. skin, nervous system)
Endoderm
Inner layer (e.g. lining of body cavity)
Mesoderm
Middle layer (e.g. circulatory, reproductive, muscular systems)
Classifying Animals
Coelom
Fluid-filled body cavity
Allows for the development of more complex organ systems
Acoelomate animals have a flattened body
Coelomate animals have a body cavity in which complex internal organs can develop
Acoelomate
Animals that have a flattened body
Coelomate
Animals that have a body cavity in which complex internal organs can develop
gives muscles a structure to brace against
allows for the development of more complex organs
Classifying Animals
Digestive Tract or Gut
One opening (bag digestive system) (ex. hydra)
Two openings (tube digestive system) (ex. earthworm)
Classifying Animals
Body Symmetry
Asymmetrical: Animals which have no symmetry at all
Radial Symmetry: Animals that are shaped like a c__ylinder or bowl__ in which their body parts are arranged around an imaginary central axis
Bilateral Symmetry: Animals that have mirror-image right and left sides. This is the most common type of symmetry. Animals have a distinct head and tail, back and bottom surfaces and two side surfaces.
Many of these animals have numerous repeating body parts called segments
The segments can become specialized for specific functions
These animals also tend to have paired limbs
Animals that have bilateral symmetry also have cephalization, the location of the majority of the sense organs and nerve cells in the head region.
Bilaterally symmetrical animals are further divided into two major branches:
Protostomes: During embryonic development the mouth forms first
Deuterostomes: During embryonic development the anus forms first
Asymmetrical
No symmetry
Ex. sponges
Radial Symmetry
Animal’s body parts are arranged around an imaginary central axis
Ex. starfish
Bilateral Symmetry
Animals that have mirror-image right and left sides
Ex. beetles
Protostomes
During embryonic development the mouth forms first
Deuterostomes
During embryonic development the anus forms first
Invertebrates
This group has the majority of animals (over 98%)
They do not have a backbone
Ex. leaches, clams, insects
Vertebrates (Chordata)
Have a notochord for at least part of their life cycle (a rodlike cord of cells that forms the main axial support i.e. backbone)
Agnathans
Jawless fishes
Gnathostomata
Jawed animals
Porifera
None
Acoelomate (flattened body)
No Symmetry
No Digestive System
Filters nutrients from the environment
No Nervous System
No Respiratory System
No Circulatory System
Ex: glass sponge, commercial sponge
Cnidaria
None
Acoelomate
Radial Symmetry
Bag Digestive System
Hunts for food w/ tentacles around mouth
Yes Nervous System
No Respiratory System
No Circulatory System
Ex: jellyfish, sea anemone
Platyheminthes
Protostomes (mouth forms first)
Acoelomate
Bilateral Symmetry
Bag Digestive System
Eat by catching food through their mouths
Yes Nervous System
No Respiratory System
No Circulatory System
Ex: flatworms, tapeworms, liverflukes
Nemotoda
Protostomes (mouth forms first)
Pseudocoelomate (body cavity isn’t fully lined but isn’t hollow)
Bilateral Symmetry
Tube Digestive System
Gulps food whole and crushes in pharynx or slurps food through a “stylet” drinking straw
Yes Nervous System
No Respiratory System
No Circulatory System
Ex: roundworms, heartworm, human whipworm
Annelida
Protostomes (mouth forms first)
Coelomate (have a body cavity in which complex internal organs can develop)
Bilateral Symmetry
Tube Digestive System
Eats food w/ a mouth and takes food from decaying animals and plants
Yes Nervous System
Yes Respiratory System
Yes Circulatory System
Ex: earthworm, leeches
Molluscs
Protostomes (mouth forms first)
Coelomate (have a body cavity in which complex internal organs can develop)
Bilateral Symmetry
Tube Digestive System
Have microscopic teeth that allow them to catch and hunt their prey
Yes Nervous System
Yes Respiratory System
Yes Circulatory System
Ex: snail. slug
Anthropods
Protostomes (mouth forms first)
Coelomate (have a body cavity in which complex internal organs can develop)
Bilateral Symmetry
Tube Digestive System
Hunting for food or catching it in its web
Yes Nervous System
Yes Respiratory System
Yes Circulatory System
Ex: spider, crayfish
Echinodermata
Deuterostome (anus forms first)
Coelomate (have a body cavity in which complex internal organs can develop)
Radial as adults, bilateral as larvae
Tube Digestive System
Attaches to and consumes prey
Yes Nervous System
No Respiratory System
No Circulatory System
Ex: starfish, sea urchin
Chordates
Deuterostome (anus forms first)
Coelomate (have a body cavity in which complex internal organs can develop)
Bilateral Symmetry
Tube Digestive System
Hunts and eats food, chews w/ hinged mouth
Yes Nervous System
Yes Respiratory System
Yes Circulatory System
Ex: dog, turtle, wolf
Rotifera
Protostomes (mouth forms first)
Pseudocoelomate (body cavity isn’t fully lined but isn’t hollow)
Bilateral Symmetry
Tube Digestive System
Hunts and eats with a mouth
Yes Nervous System
No Respiratory System
No Circulatory System
Ex: prarotatoria, monogononta
Note
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