bio 100 get this shit done

Explain how the first photosynthesizers evolved into modern plants

Cyanobacteria became chloroplasts through endosymbiosis and land plants evolved cuticles, stomata, vascular tissues, lignin, seeds, and flowers.

Four major periods of plant evolution

Bryophytes first, then seedless vascular plants, then gymnosperms, then angiosperms.

Bryophytes

Nonvascular plants that are gametophyte-dominant and require water for fertilization.

Seedless vascular plants

Vascular plants that are sporophyte-dominant and reproduce with spores.

Gymnosperms

Seed plants with cones and pollen that do not produce fruit.

Angiosperms

Flowering plants that produce seeds within fruits and undergo double fertilization.

Xylem

Tissue that transports water and minerals upward and is dead at maturity.

Phloem

Tissue that transports sugars throughout the plant and is alive at maturity.

Cuticle

Waxy protective coating that reduces water loss.

Stomata

Pores that allow gas exchange and are controlled by guard cells.

Lignin

Structural material that strengthens vascular tissues for upright growth.

Gametangia

Structures that protect gametes from drying out.

Flower reproductive parts

Anther and filament are male parts; stigma, style, and ovary are female parts.

Definition of animal

Multicellular eukaryotic heterotrophs that ingest food.

Porifera

Asymmetrical animals with no true tissues that filter feed.

Cnidaria

Radially symmetrical animals with stinging cells and a gastrovascular cavity.

Platyhelminthes

Bilateral acoelomate flatworms with simple organs.

Nematoda

Bilateral pseudocoelomate roundworms with a complete digestive tract.

Annelida

Segmented worms with a coelom and a closed circulatory system.

Mollusca

Animals with a mantle and often a shell and mostly open circulation.

Arthropoda

Animals with exoskeletons, jointed limbs, and segmentation.

Echinodermata

Radial adult animals with a water vascular system.

Chordata

Animals with a notochord, dorsal nerve cord, and pharyngeal slits.

Endothermic

Organisms that maintain constant internal body temperature.

Exothermic

Organisms that rely on external heat sources.

Four tissue types

Epithelial, connective, muscle, and nervous tissues.

Homeostasis

Maintenance of stable internal conditions.

Population

A group of the same species living in an area.

Community

All living species in an area.

Ecosystem

A community plus nonliving environmental factors.

Biosphere

All ecosystems on Earth.

Population size vs density

Size is the number of individuals and density is number per unit area.

Mark-recapture

Method to estimate populations of mobile animals.

Quadrat sampling

Method to estimate populations of plants or sessile organisms.

Clumped dispersion

Individuals grouped together making estimates less accurate.

Uniform dispersion

Individuals evenly spaced.

Random dispersion

Individuals randomly spread making estimates easier.

Exponential growth

J-shaped growth under unlimited resources.

Logistic growth

S-shaped growth limited by carrying capacity.

Carrying capacity

Maximum population an environment can support.

Density-dependent factors

Competition, predation, and disease.

Density-independent factors

Weather and natural disasters.

Type I survivorship

High survival until old age.

Type II survivorship

Constant death rate over life.

Type III survivorship

High death rate in young.

Opportunistic species

Many offspring and low parental care.

Equilibrial species

Few offspring and high parental care.

Ecological footprint

Amount of land needed to support resource use.

Ecological niche

An organism’s role and resource use.

Competitive exclusion principle

No two species can occupy the same niche.

Types of interspecific interactions

Competition, predation, herbivory, parasitism, mutualism, commensalism.

Primary succession

Community development starting without soil.

Secondary succession

Community development where soil is already present.

Trophic levels

Feeding levels such as producers, consumers, and decomposers.

Energy flow vs chemical cycling

Energy flows one way and nutrients cycle repeatedly.

Food chain vs food web

Chains show one feeding path and webs show many.

Energy pyramid

Shows decreasing energy with each trophic level.

Water cycle

Movement of water through evaporation, condensation, and precipitation.

Carbon cycle

Movement of carbon through photosynthesis, respiration, and combustion.

Nitrogen cycle

Movement through fixation, nitrification, assimilation, and denitrification.

Phosphorus cycle

Movement of phosphorus from rocks to soil to organisms.

Biomes

Major climate-based ecosystems such as tundra, desert, and rainforest.

Aquatic ecosystems

Lakes, rivers, wetlands, estuaries, coral reefs, and open ocean.

Human impacts

Climate change, pollution, habitat destruction, and overexploitation.

Endangered species

Species at high risk of extinction.

Threatened species

Species likely to become endangered.

Endemic species

Species found only in one geographic area.

Biodiversity levels

Genetic, species, and ecosystem diversity.

Conservation biology

Science of protecting biodiversity.

Ecological restoration

Returning damaged ecosystems to a natural state.

Sustainable development

Using resources in a way that preserves them for the future.