Prokaryotes and Protists Overview

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Questions and Answers

What is a characteristic feature of prokaryotes?

Complex multicellular structure

Presence of a nucleus

Reproduce through sexual reproduction

Lack of organized nucleus and organelles (correct)

Which of the following correctly identifies a classification of archaea?

Dinoflagellates

Halophiles (correct)

Protozoa

Chemoautotrophs

What is the primary role of cyanobacteria?

Serving as a pathogenic bacteria

Causing infectious diseases

Breaking down dead organic matter

Producing oxygen through photosynthesis (correct)

Which of the following is a characteristic of slime molds?

Heterotrophic decomposers Signup and view all the answers

Which organism is classified as a protozoan?

Giardia Signup and view all the answers

What distinguishes algae from other groups of protists?

Autotrophic capability Signup and view all the answers

What is the primary feature of pathogenic bacteria?

Induce diseases in hosts Signup and view all the answers

Which of the following best characterizes protozoans?

Animal-like heterotrophs that often move Signup and view all the answers

Which characteristic is unique to seed plants compared to nonvascular and seedless vascular plants?

Production of seeds Signup and view all the answers

What is the main function of phloem in vascular plants?

Transport nutrients and sugars Signup and view all the answers

Which of the following interactions is characterized as mutualism?

Bee pollination of flowers Signup and view all the answers

What distinguishes vertebrates from invertebrates?

Presence of a backbone Signup and view all the answers

What is a primary benefit of having vascular tissue in plants?

Ability to grow taller and transport nutrients Signup and view all the answers

What is a key trait of fungi that sets them apart from plants?

Heterotrophic nutrition Signup and view all the answers

What defines a carrying capacity in ecology?

The maximum number of individuals an environment can sustain Signup and view all the answers

Which of the following describes a keystone species?

A species that has a significant impact on its ecosystem Signup and view all the answers

What are invasive species known for?

Outcompeting native species for resources Signup and view all the answers

What type of growth curve describes a population that stabilizes after reaching carrying capacity?

Logistic growth Signup and view all the answers

What are R-selected species typically characterized by?

Short life spans and rapid reproduction Signup and view all the answers

What defines a community in ecology?

Different species living in the same area Signup and view all the answers

What is the impact of decomposer fungi in ecosystems?

They help break down dead organic matter Signup and view all the answers

Study Notes

Prokaryotes (Bacteria and Archaea)

Characteristics: Unicellular, lack a nucleus and organelles, reproduce via binary fission, can be autotrophs or heterotrophs (some obtain energy from chemical reactions, others produce food like plants).
Movement: Often use flagella (long tails) or cilia (tiny hairs).
Examples: Pathogenic (harmful): Yersinia pestis (plague), Clostridium botulinum (botulism); Beneficial: Cyanobacteria (produce oxygen), many types of bacteria in the human microbiome (important for digestion, immunity, etc).
Human Microbiome: Bacteria living on and in humans. Examples: E. coli (used to make medicine like insulin), oil-eating bacteria (clean up oil spills), bioluminescent bacteria (camouflage in squids).
Archaea: Two classifications include halophiles (salt-loving) and thermophiles (heat-loving).

Protists

Characteristics: Eukaryotic (have a nucleus and organelles), often unicellular, not plants, animals, or fungi.
Nutrition: Can be autotrophs (producing their own food), heterotrophs (consuming other organisms), or mixotrophs (both).
Reproduction: Can reproduce asexually or sexually.
Groups:
- Protozoa ("animal-like"): Heterotrophic, move using flagella, cilia, or pseudopods (e.g., amoeba). Examples include Giardia (causes giardiasis), Trypanosoma (causes sleeping sickness), and Plasmodium (causes malaria). Brain-eating amoeba is another example - focus on Plasmodium and malaria for exam preparation as requested.
- Algae ("plant-like"): Photoautotrophs (performing photosynthesis), usually found in water. Examples include diatoms (important producers of oxygen) and dinoflagellates (many are symbiotic).
- Slime molds ("fungus-like"): Decomposers, consume dead plants and animals.

Fungi

Characteristics: Heterotrophic (rely on consuming others for nutrition) eukaryotes, more closely related to animals than plants, reproduce via spore dispersal, have chitin cell walls. Fungi are decomposers of dead matter, breaking it down to be used in the ecosystem.
Environmental Impact: Important decomposers, breaking down dead plants and animals.

Plants

Characteristics: Eukaryotic, have cellulose cell walls, store carbohydrates as starch, photosynthesize (using chlorophyll), have specialized tissues (roots, leaves, stems).
Evolution and Adaptation: Adapting to live on land involved developing vascular tissues, seeds to protect the embryo, and reproductive structures (flowers and fruit). Early plants were dependent on water and moisture.
Groups:
- Nonvascular: Lack vascular tissue (e.g., mosses), reliant on water for reproduction.
- Seedless vascular: Have vascular tissue but do not produce seeds (e.g., ferns).
- Seed plants: Have vascular tissue and seeds. Further divided into gymnosperms (no flowers or fruit) and angiosperms (bearing flowers and fruit). Angiosperms produce fruit (from the ovary of the flower), which protects and helps disperse the seeds.
Vascular Tissue: Xylem transports water, and phloem transports nutrients. This allows for taller stature.
Seeds: Protect the embryo, aid in long-term survival.
Flowers/Fruit: Flowers attract pollinators, fruits aid in seed dispersal.

Animals

Characteristics: Eukaryotic, heterotrophic, mobile at some point in their life cycle, have tissues and body symmetry, similar developmental patterns during embryonic development.
Vertebrates vs. Invertebrates: Vertebrates have a backbone and spinal cord; invertebrates do not.
Key Groups: (Note examples are limited and you are responsible for memorizing the examples stated in your lecture).
- Cnidarians: Jellyfish, corals (have stinging cells).
- Sponges (Porifera): Lack true tissues.
- Flatworms
- Mollusks
- Arthropods
- Chordates: (includes vertebrates)
- Amphibians
- Reptiles
- Birds
- Mammals
- Marsupials
Vertebrate Evolution: Fish are the first vertebrates to evolve. Amniotic eggs were a critical adaptation for life on land.

Population Ecology

Ecology: Study of living organisms and their interactions with the environment.
Population: Group of the same species living in a given area.
Population Density: Number of individuals per unit area.
Dispersion Patterns: Random, clumped, uniform.
Growth Curves: Exponential (J-shaped) and Logistic (S-shaped).
Carrying Capacity: Maximum population size an environment can sustain.
Life History: Characteristics affecting reproduction and survival.
R- and K-selected species: Differences in reproductive strategies.
Sustainable Resource Management: Harvesting resources without damaging the resources.

Communities and Ecosystems

Community: Different populations of organisms living and interacting in the same area.
Interspecific Interactions:
- Competition: Different species vying for resources.
- Predation: One species consuming another.
- Herbivory: An animal consuming plant material.
- Parasitism: One species benefits, the other is harmed.
- Mutualism: Both species benefit.
- Commensalism: One species benefits, the other is unaffected.
Trophic Levels: Feeding positions in a food web.
Foundation Species: Species that create or maintain habitats for other species.
Invasive Species: Non-native species harming native species.
Keystone Species: Species with major impacts in their ecosystem, their absence may cause great ecological consequences.
Ecosystem: Community of organisms and their environment.

Conservation

Biodiversity: Three main components – genetic diversity, species diversity, and ecosystem diversity.
Endangered/Threatened Species: Species facing extinction/at risk of extinction.
Threats to Biodiversity: Habitat loss, climate change, invasive species, overexploitation, pollution.
Conservation Strategies: Protecting habitats, controlling invasive species, sustainable resource management, and establishing protected areas, among others.

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Description

This quiz covers the fundamental characteristics of prokaryotes, including bacteria and archaea, as well as protists. Learn about their structures, reproduction methods, movement, and roles in the human microbiome. Test your understanding of the differences between these microorganisms and their significance in various ecosystems.