biodiversity exam 3

angiosperms

flowering plants; produce seeds enclosed in fruit. Most diverse plant group. divived between two clades -eudicots and -monocots

Eudicots

major group of angiosperms; have two seed leaves (Cotyledons), net-like veins, and flower pedals in 4 or 5

monocots

one sed leaf(cotyledon), parallel leaf vein(bundles of vascular tissues), fibrous roots, and flower pedals in muliples of 3

Monocot or Eudicot?

Monocot-Becasue flower parts in multiples of 3 (6 petals), parallel leaf veins - common in monocot

and 1 cotyledon

this is a lily flower

pollen

male gametophyte; carries sperm cells to the female ovule

fruit

matrure ovary of a flower, proects and aids in seed disperal

flower anatomy

Sepals (protect bud), Petals (attract pollinators), Stamens (male—anther + filament), Carpels/Pistil (female—stigma, style, ovary).

flower reproduction

• Pollination: Transfer of pollen to stigma.

• Fertilization: Sperm fertilizes egg to form zygote.

• Double Fertilization: One sperm → egg (zygote), other sperm → central cell (endosperm = nutrition for embryo).

Fungi anatomy

• Made of hyphae (threadlike filaments) forming a mycelium.

• Cell walls of chitin. Absorb nutrients externally (heterotrophs).

Fungi reproductive cycle

• Can reproduce sexually (via spores from meiosis) or asexually (by budding or spore production).

• Often alternate between haploid, dikaryotic, and diploid stages.

What is the ecological role of fungi?

• Decomposers (recycle nutrients), mutualists, and pathogens.

• Critical for nutrient cycling and plant health.

what are the major groups of fungi?

• Basidiomycota: Club fungi—mushrooms, puffballs. Produce spores on basidia.

• Ascomycota: Sac fungi—yeast, molds, morels. Produce spores in asci.

Lichens

• Symbiosis between fungus (structure) and alga or cyanobacterium (photosynthesis).

• Important colonizers of bare rock and nutrient-poor environments.

mycorrhizal associations

• Ectomycorrhizae: Fungus forms sheath around roots; exchange nutrients with plant.

• Endomycorrhizae (Arbuscular): Fungal hyphae penetrate root cells.

• Function: Help plants absorb water/minerals; fungus gains carbohydrates.

ECTOmycorrhizal

• Fungus forms sheath around roots; exchange nutrients with plant.

• OUTSIDE OF CELL

ENDOmycorrhizal

• : Fungal hyphae penetrate root cells.

• INSIDE OF CELL

Parasitic Fungi

feed on living organism, sometimes causing disease

White - nose syndrome

Fungal disease affecting bats, caused by Pseudogymnoascus destructans; disrupts hibernation and causes high mortality.

What are the stages of animal development?

Zygote → Cleavage → Blastula → Gastrula → Organogenesis.

Animal development - evolution of tissues

• No true tissues: Sponges (Porifera).

• Diploblastic: Two layers (ectoderm & endoderm) — Cnidaria.

• Triploblastic: Three layers (adds mesoderm) — all other animals.

what is double fertilization?

One sperm fertilizes egg → zygote; other fertilizes central cell → endosperm (nutritive tissue).

Evolution of body cavities

Coelom-body cavity

• Acoelomate: No body cavity (flatworms).

• Pseudocoelomate: Cavity not fully lined with mesoderm (nematodes).

• Coelomate: True coelom fully lined by mesoderm (earthworms, humans).

evolution of symmetry

• Asymmetrical: No symmetry (sponges).

• Radial: Symmetry around central axis (jellyfish).

• Bilateral: Two mirrored sides; allows cephalization (most animals).

Porifera

Sponges

• Unique Traits: No true tissues/organs; filter feeders; sessile adults.

• Anatomy: Pores, spongocoel (central cavity), choanocytes (feeding cells).

• Ecological Role: Filter water; habitat for microorganisms; reef structure.

Cnidaria

• Unique Traits: Stinging cells (nematocysts), radial symmetry.

• Anatomy: Two layers (epidermis, gastrodermis), gastrovascular cavity.

• Reproduction: Alternates between polyp (sessile) and medusa (free-swimming) forms.

• Diversity: Corals (build reefs), anemones (sessile), Portuguese man-of-war (colonial), jellyfish (medusa).

what is a nematocyst

Cnidocyte with nematocyst is
the defining characteristic of the
group.
These cells sting and grab prey.

Cnidaria - anatomy

Epidermis (E) : outer layer of the
organism.
Mesoglea (M) : extracellular matrix that
functions as hydrostatic skeleton.
Gastrodermis (G) : inner layer of the
organism. 

what is extracellular digestion

enzymes break down food particles and cells of the gastrodermis absorb the nutrients. Digestion in the gastrovascular cavity(only one opening)

characteristic of jellyfish

cnidaria reproduction cycle

Flatworms (Platyhelminthes)

• Traits: Acoelomate, bilateral, simple organs, no circulatory system.

• Ecology: Free-living (planarians) or parasitic (tapeworms, flukes).

Nematodes (Roundworms

• Traits: Pseudocoelomate, complete digestive tract, tough cuticle.

• Ecology: Soil decomposers, parasites (e.g., hookworms, C. elegans model organism).

Fungi reproductive cycle

Flower Morphology

flower reproductive cycle