UPCAT Biology — Taxonomy & ClassificationFlash Cards

What is taxonomy and who developed the modern classification system?

Taxonomy is the branch of biology that categorizes living things into groups called taxa based on shared characteristics. The modern classification system was developed by Swedish botanist Carolus Linnaeus in the 18th century, and his system is still used today with modifications.

List the eight taxonomic ranks from broadest to most specific.

Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species. Remember the mnemonic: 'Dear King Philip Came Over For Good Soup' to memorize the order.

What are the three domains of life and their basic characteristics?

1. Bacteria - prokaryotic, single-celled organisms without nucleus 2. Archaea - prokaryotic, single-celled organisms with unique biochemistry 3. Eukarya - organisms with cells containing nucleus and membrane-bound organelles, can be unicellular or multicellular

Name the six kingdoms of life and give one example of each.

1. Eubacteria (E. coli) 2. Archaebacteria (methane bacteria) 3. Protista (amoeba, algae) 4. Fungi (mushrooms, yeast) 5. Plantae (trees, flowers) 6. Animalia (mammals, sponges)

Compare prokaryotic and eukaryotic cells in terms of cell structure.

Prokaryotic cells: No nucleus, no membrane-bound organelles, genetic material freely floating in cytoplasm. Found in Bacteria and Archaea. Eukaryotic cells: Have nucleus, membrane-bound organelles (mitochondria, ER, etc.), genetic material enclosed in nuclear membrane. Found in Protista, Fungi, Plantae, and Animalia.

What is binomial nomenclature and how is it written?

Binomial nomenclature is the two-part scientific naming system using genus and species. Format: Genus species (e.g., Homo sapiens for humans). Rules: Always italicized, genus capitalized, species lowercase. This system ensures each organism has a unique scientific name worldwide.

Describe the key characteristics that distinguish the kingdom Fungi from other kingdoms.

Fungi characteristics: - Eukaryotic cells - Cell walls made of chitin (not cellulose) - Heterotrophic nutrition (absorb nutrients) - Mostly multicellular (some unicellular like yeast) - Reproduce by spores - Include mushrooms, molds, yeasts - Important decomposers in ecosystems

What distinguishes Kingdom Plantae from other kingdoms?

Plantae characteristics: - Eukaryotic cells with cellulose cell walls - Autotrophic nutrition (photosynthesis) - Multicellular with tissue organization - Non-motile - Produce oxygen and serve as primary producers - Include trees, flowers, ferns, mosses - Essential for life on Earth

What are the main characteristics of Kingdom Animalia?

Animalia characteristics: - Eukaryotic cells without cell walls - Heterotrophic nutrition - Multicellular with organ system organization - Motile (can move) - Sexual reproduction common - Wide ecological impact - Include mammals, birds, fish, insects, sponges

What is a diplontic life cycle and which organisms exhibit it?

Diplontic life cycle: Mitotic division occurs only in diploid cells. The haploid phase is limited to gametes produced by meiosis. The diploid zygote undergoes mitosis to develop into multicellular diploid organisms. Animals are examples of diplonts.

Explain the haplontic life cycle with examples.

Haplontic life cycle: Mitosis occurs only in haploid cells. Gametes form through mitosis, and the zygote is the only diploid stage. The zygote undergoes meiosis to form spores, which then divide mitotically. Examples include most fungi and some green algae like Chlamydomonas.

What is alternation of generations and which organisms show this pattern?

Alternation of generations (haplo-diplontic life cycle): Mitosis occurs in both haploid and diploid stages. Organisms alternate between multicellular haploid gametophyte and multicellular diploid sporophyte phases. Examples include many algae and all terrestrial plants.

Distinguish between isomorphic and heteromorphic alternation of generations.

Isomorphic: Gametophyte and sporophyte have similar morphology (appearance). Example: Ulva, Cladophora. Heteromorphic: Gametophyte and sporophyte have different morphologies. Example: Laminaria (brown algae) where the large sporophyte looks very different from the small gametophyte.

What is phylogeny and how does it differ from traditional classification?

Phylogeny is the study of evolutionary relationships among organisms. Unlike traditional classification based on physical similarities, phylogenetic classification groups organisms according to their common ancestors and evolutionary history. This approach is more reliable because similar appearance doesn't always indicate close relationship.

What is cladistic analysis and what tool does it use?

Cladistic analysis is a method that uses cladograms to examine evolutionary relationships. It focuses on derived characters (new characteristics) that arise in lineages. On a cladogram, organisms further down a branch share more recent common ancestors and possess the derived traits that appeared at each branching point.

What are the four major supergroups of Domain Eukarya?

The four supergroups of Domain Eukarya are: 1. Excavata (diplomonads, euglenozoans) 2. SAR Clade (stramenopiles, alveolates, rhizarians) 3. Archaeplastida (red algae, green algae, plants) 4. Unikonta (amoebozoans, fungi, animals)

Give the complete taxonomic classification of humans.

Human taxonomy: Domain: Eukarya Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Primates Family: Hominidae Genus: Homo Species: sapiens Scientific name: Homo sapiens

Compare the cell wall composition across different kingdoms.

Cell wall materials by kingdom: - Eubacteria: Peptidoglycan - Archaebacteria: Uncommon lipids - Protista: Pectin or none (green algae have cellulose) - Fungi: Chitin - Plantae: Cellulose - Animalia: No cell wall

What is the difference between autotrophic and heterotrophic nutrition? Give examples.

Autotrophic nutrition: Organisms make their own food through photosynthesis or chemosynthesis. Examples: plants, some bacteria. Heterotrophic nutrition: Organisms obtain food by consuming other organisms. Examples: animals, fungi, most bacteria. Methods include absorption (fungi) or ingestion (animals).

Why was the kingdom Protista abandoned in modern classification systems?

Kingdom Protista was abandoned because advances in phylogenetic analysis revealed that protists are not a natural group. Some protists are more closely related to plants, fungi, or animals than to other protists. This made Protista a 'wastebasket' category rather than a true evolutionary group, so protists are now distributed among the four supergroups of Eukarya.