Biology Chapter on Taxonomy & Classification

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What type of organisms form a symbiotic relationship in lichens?

A fungus and a vascular plant

A bacteria and a protozoan

Two different fungi

A fungus and a cyanobacterium or an alga (correct)

Which of the following statements accurately describes hyphae?

They are involved in the sexual reproduction of plants.

They are the reproductive structures of fungi.

They are single-celled organisms.

They form the body structure of most fungi. (correct)

What is the primary function of the oral groove in a ciliate?

Photosynthesis

Reproduction

Movement and locomotion

Digestion and food intake (correct)

What is the characteristic feature of euglenoids like Euglena?

They possess chloroplasts for photosynthesis. Signup and view all the answers

What type of spores is produced through the process of conjugation in zygomycete fungi?

Zygospore Signup and view all the answers

In terms of genetic diversity, what is the primary difference between asexual and sexual reproduction?

Asexual reproduction has very low genetic diversity. Signup and view all the answers

Which of the following describes a sporangium?

It is a reproductive structure that produces spores. Signup and view all the answers

What is the main characteristic of heterotrophs?

They depend on other organisms as food sources. Signup and view all the answers

Which type of organism is characterized as living in a high-salt environment?

Halophiles Signup and view all the answers

What type of organism is classified as a plasmodium?

A wall-less mass of cytoplasm of an acellular slime mold Signup and view all the answers

What are the two names assigned to an organism in the binomial nomenclature system?

Genus and Species Signup and view all the answers

Which structure is specifically responsible for producing ascospores in fungi?

Ascus Signup and view all the answers

Which characteristic is unique to fungi among the kingdoms discussed?

Cell walls containing chitin Signup and view all the answers

What type of organism can produce energy both in the presence and absence of oxygen?

Facultative Anaerobes Signup and view all the answers

Which of the following is an example of an autotroph?

Euglena Signup and view all the answers

In lichen, which relationship exists between fungi and photosynthetic organisms?

Mutualism Signup and view all the answers

What reproductive method involves the transfer of DNA between two bacterial cells?

Conjugation Signup and view all the answers

Which organisms are classified within the kingdom Eubacteria?

Prokaryotic single-celled organisms Signup and view all the answers

What type of spore is produced in the ascus of ascomycete fungi?

Ascospore Signup and view all the answers

Which term describes a plant that produces flowers and seeds within an ovary?

Angiosperm Signup and view all the answers

What is the main component of the cell walls in fungi?

Chitin Signup and view all the answers

What type of bacteria can survive only in the absence of oxygen?

Obligate Anaerobes Signup and view all the answers

Which group of organisms does the kingdom Animalia NOT include?

Organisms with cell walls Signup and view all the answers

What is the function of chlorophyll in organisms?

Capture light energy for photosynthesis Signup and view all the answers

What is the primary role of the algae in the symbiotic relationship of lichens?

To provide nourishment through photosynthesis Signup and view all the answers

Which of the following is a type of green algae that forms colonial structures?

Volvox Signup and view all the answers

Which characteristic is NOT true for fungi?

Fungi have cell walls composed of cellulose Signup and view all the answers

What structure do Euglena possess that allows them to detect light?

Eyespot Signup and view all the answers

In the life cycle of yeast, what is the process called where they reproduce asexually?

Budding Signup and view all the answers

What role do mycorrhizae play in the relationship with plant roots?

They increase nutrient absorption for plants Signup and view all the answers

Which type of fungal reproduction occurs under favorable conditions?

Asexual reproduction Signup and view all the answers

Which of the following is an accurate description of the structure of zygomycota fungi?

Spores in a case-like structure Signup and view all the answers

What distinguishes animal-like protists from plant-like protists?

Ability to photosynthesize Signup and view all the answers

Which type of plant-like protist is known for having bi-flagellated cells?

All of the above Signup and view all the answers

Which characteristic is typical of amoebas?

They feed through endocytosis Signup and view all the answers

Which of the following is NOT a characteristic of all animals?

Lack specialized tissues Signup and view all the answers

What is the correct sequence of steps in the lytic cycle of viral reproduction?

Infection, replication, lysis Signup and view all the answers

Study Notes

Taxonomy & Classification

Linnaeus developed binomial nomenclature (two names) to classify organisms.
Each organism has a genus and species name.
Scientific names are written in italics or underlined. Only the first letter of the genus is capitalized.

Definitions

Aerobes use oxygen to produce energy
Obligate aerobes require oxygen to survive.
Anaerobes don't need oxygen to produce energy.
Obligate anaerobes can only live without oxygen.
Facultative anaerobes can use oxygen or not.
Anaerobic methanogens are bacteria that live in oxygen-free environments and release methane gas.

Kingdoms of Life

Animalia: multicellular, heterotrophic, eukaryotic with cells lacking cell walls.
Archaebacteria: prokaryotic, single-celled organisms genetically different from Eubacteria. Found in harsh environments.
Eubacteria: prokaryotic, single-celled organisms; contains most bacteria species.
Fungi: eukaryotic, multicellular, heterotrophic with cell walls containing chitin. Examples are mushrooms, yeasts and molds.
Plantae: mostly multicellular, autotrophic organisms.
Protista: mostly unicellular, eukaryotic organisms.

Key Terms

Autotrophs: produce their own food.
Heterotrophs: obtain energy from other organisms.
Chitin: strong, waterproof carbohydrate found in arthropod exoskeletons and the cell walls of fungi.
Chlorophyll: captures light energy in chloroplasts.
Chloroplast: organelle that contains chlorophyll and converts sunlight to chemical energy in plants and some Protists.

Reproduction in Organisms

Asexual Reproduction: one parent, offspring identical to parent. Mutations are the only source of genetic variation.
Sexual Reproduction: two parents, offspring genetically different from parents. Crossing over and random assortment create genetic variation.

Viruses

Viruses are not classified as a kingdom.
Viruses are not alive.
Viruses are parasitic and require a host for reproduction, nutrition, respiration, and other functions.
Viruses can alter the host cell's genetic makeup.
Lytic Cycle: a viral replication cycle that always ends with the lysis of the host cell.
Lysogenic Cycle: viral DNA inserts into the host's DNA and is copied during cell division, delaying the release of new viruses.

Protists

Eukaryotic organisms that appeared 1.5 billion years ago.
Diverse species, making classification challenging.
Protists are classified based on their nutrition.

Animal-like Protists

Heterotrophic, unicellular, lack cell walls.
Live in aquatic ecosystems, wet soil, or fluids within a host. Some are parasites.

Amoebas

Single-celled, undefined body shape.
Use pseudopods for movement.
Feed using endocytosis. Some are parasites.

Paramecium

Single-celled, uses cilia for movement.
Cilia sweep food into the oral groove, which leads to a food vacuole.
Waste is expelled through the anal pore.

Fungus-like Protists

Heterotrophic, decomposers, feed via endocytosis.
Live in cool, damp habitats.

Water Molds

Filamentous.
The whitish cottony mold found on dead fish.
Saprophytic, consume dead organic matter. Caused the Irish Potato Famine.

Plant-like Protists

Contains plastids and are photosynthetic.

Euglena

Unicellular, freshwater organisms.
Use flagella for movement.
Can be autotrophic or heterotrophic.
Have a red, light-sensitive structure called the eye spot.

Green Algae

Photosynthetic.
Single-celled, colonial, or multicellular.
Bi-flagellated cells.
Primarily live in freshwater.
Chlamydomonas: single-celled.
Volvox: colonial. Hundreds of connected singe, biflagellated cells form a hollow green sphere.

Fungi

Characteristics: eukaryotic, multicellular, heterotrophic (saprophytic), cell walls containing chitin, reproduce both sexually and asexually.
Hyphae are thread-like filaments that make up the body of most fungi.
Mycelium: a tangled mass of hyphae that absorbs nutrients for food.

Classification of Fungi

Classified based on sexual reproduction patterns:
- Zygomycota: spores produced in a case-like structure (sporangium).
- Ascomycota: spores produced in a sac-like structure (ascus).
- Basidiomycota: spores produced in club-like structures (basidium).
Spores: haploid reproductive cells.
Sexual reproduction generally occurs under unfavorable conditions.

Examples of Fungi

Case-like Fungi (Zygomycota)

Bread Mold: Asexual: hyphae extends along the surface and into food. Black sporangia form, releasing spores via wind. Sexual: zygospore forms upon contact and remains dormant until conditions improve. Two genetically different hyphae are produced.

Sac-like Fungi (Ascomycota)

Penicillium: Alexander Fleming discovered penicillin, the first antibiotic. It releases a chemical that inhibits bacterial growth.
Yeasts: unicellular fungi. Asexual: Occurs via budding in favorable conditions. Sexual: forms ascospores that remain dormant until conditions improve. Anaerobic respiration (fermentation) releases CO2 and ethanol as byproducts.

Club-like Fungi (Basidiomycota)

Gilled Mushrooms: gills on the underside contain thousands of basidia, each with thousands of spores that are dispersed by wind.
Imperfect Fungi: Examples include athlete's foot.

Fungal Associations

Lichens: Symbiotic association of fungus with a cyanobacterium or algae. The algae provides food through photosynthesis, the fungus provides water, minerals, and protection from dryness.
Mycorrhizae: Fungal mycelium forms a symbiotic association with plant roots. Mycelium forms a web over the plant roots and provides water and minerals from the soil while the plant roots provide amino acids and sugars.

Characteristics of Animals

Heterotrophic, multicellular, eukaryotes.
Specialized nervous and muscular tissues.
Lack cell walls.
Primarily sexual reproduction.

Classification of Animals

Symmetry: Asymmetrical, bilateral, or radial.
Cell Organization: cells function independently or form tissues and organs.
Coelom: Presence of an internal body cavity.

Simple Animals

Phylum Porifera (sponges)

Most primitive animals.
All aquatic, mostly marine.
Sessile, directly attached to a surface.
Absorb water through tiny pores (ostia) and expel water through larger pores (oscula).
Reproduction: sexually (hermaphrodites) and asexually (budding).

Phylum Cnidaria

Radial symmetry.
Cells organized into tissues.
Examples: jellyfish, corals, anemones.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on the taxonomy and classification of living organisms, touching upon the system developed by Linnaeus. Explore definitions related to aerobes and the different kingdoms of life, understanding their unique characteristics and requirements.