Biology Homework #1: Species Concepts

Homework #1

• Lions, elephants, and dogs are examples of the biological species concept, where they interbreed and produce fertile offspring.
• Lions occasionally interbreed with tigers (unnatural circumstances), but the offspring is usually infertile.
• Dogs interbreed to create different dog breeds, all part of the same species.
• Elephants are categorized into different species (African and Asian), where interbreeding between species is rare.
• Species classification can be based on morphology where species can reproduce asexually.
• Evolution and adaptation in a habitat can result in separate species.
• Traveling between areas may prevent species from ever interbreeding again.
• A heterotroph is an organism that obtains energy by consuming other organisms (e.g., humans).
• An autotroph is an organism that creates its own energy (e.g., plants).
• Coral reefs provide cleaning stations for fish (removed by small fish and shrimp).
• Trillium seed dispersal is assisted by ants.
• Hermit crabs use snail shells for protection.

Notes #1

• Species diversity measures the variety and evenness of species in an area.
• Species richness measures the number of different species.
• Relative abundance measures the distribution of individuals of species (how evenly they are spread out).
• A forest with a number of species equally abundant is more diverse than a forest with a dominant species.

Species Richness and Relative Abundance

• Species richness is simply the count of different species in a given area.
• Relative abundance describes the distribution of individuals across different species in an area—how many individuals are there of each species.

6 Kingdoms of Biology

• Kingdom Animalia: Multicellular, eukaryotic, heterotrophic, reproducing sexually.
• Kingdom Plantae: Multicellular, eukaryotic, autotrophic, reproducing asexually and sexually.
• Kingdom Fungi: Some single or multicellular, eukaryotes, heterotrophic, reproducing through budding or spores.
• Kingdom Protista: Single-celled, eukaryotes, can consume or produce energy, reproducing via binary fission, spores, budding etc..
• Kingdom Eubacteria: Single celled, prokaryotes, with a variety in their nutrition.
• Kingdom Archaea: Single celled, prokaryotes, heterotrophic or autotrophic, reproducing via binary fission.

Taxonomy

• Taxonomy, also known as systematics, is the science of classifying organisms (both living and fossilised).
• Carl Linnaeus developed the binomial nomenclature system, a two-part naming system (genus and species) for organisms.

Biodiversity

• Biodiversity is the variety and diversity of life in different environments.
• Ecosystems with high biodiversity are often more resilient to environmental changes.
• Genetic diversity influences an adaptation for species.
• Variation in genes among individuals of the same species affects the ability to adjust or evolve.
• Communities which influence the variety are closely connected.

Evolution

• Evolution is the change of species over time.
• Phylogeny is the study of the evolutionary relationship between organisms.
• Phylogenetic trees—maps of life—illustrate the evolutionary relationships among organisms.
• Clades are groups of species with a common ancestor.

Taxonomy

• Taxonomy is the process of classifying organisms.
• Taxonomy uses categories to organise organisms based on characteristics.
• Dichotomous keys aid in the identification of organisms.

Dichotomous Key

• A dichotomous key consists of paired statements describing characteristics of an organism.
• Using the key, users select characteristics based on the traits of the organism to identify it.

Prokaryotic vs. Eukaryotic

• Prokaryotes lack a nucleus and membrane-bound organelles.
• Eukaryotes have a nucleus and membrane-bound organelles.
• Examples of Prokaryotes: bacteria and Archaea.
• Examples of Eukaryotes: Protists, Fungi, plants, and animals.

Viruses

• Viruses are nonliving entities that require a host for reproduction.
• Viruses have genetic material (DNA or RNA) enclosed in a protein coat (capsid).
• Viral reproduction can either be lytic or lysogenic.
• In a lytic cycle viruses replicate, then infect host cells; in the lysogenic cycle the virus's DNA integrates to host cell's DNA and replicates along with host DNA.

Bacteria

• Bacteria are single-celled, prokaryotic organisms.
• Bacteria reproduce asexually via binary fission.
• Gram staining identifies cell walls of bacteria.
• Bacteria are involved in decay, fermentation processes and as pathogens.

Pandemic, Epidemic, or Endemic

• Pandemic: global viral infection.
• Epidemic: widespread viral infection in a specific region.
• Endemic: sustained viral infection in a given region.

Kingdom Protista

• Protists are eukaryotic, single-celled or multicellular organisms.
• Protists can be plant-like, animal-like or fungi-like.
• Examples include Protozoans and algae.
• Protists exhibit different nutritional methods

Fungi

• Fungi are eukaryotic organisms, multicellular or single-celled.
• Most fungi are decomposers, breaking down dead material.
• Some fungi cause plant diseases or affect crops.
• Fungi have vital roles in ecosystems.
• Fungi-like protists are diverse organisms.

Plants

• Plants are multicellular, eukaryotic organisms.
• Plants are photosynthetic, using sunlight to produce their own food.
• Plants can be vascular or non-vascular.
• Plants reproduce sexually and asexually.

Flowering Plants

• Flowering plants (angiosperms) produce flowers and fruits.
• Flowering plants have diverse structures.
• Flowering plants are vital for ecosystems.

Animals

• Animals are multicellular, eukaryotic organisms.
• Animals are heterotrophic, consuming other organisms for energy.
• Animals have tissues and organs.
• Animals exhibit a wide range of body plans and adaptations.

Invertebrates and Vertebrates

• Invertebrates: Animals without a backbone, various groups like Mollusks and Arthropods.
• Vertebrates: Animals with a backbone, containing fish, amphibians, reptiles, birds and mammals.
• Animals develop in stages like blastula and gastrula.
• Many animals exhibit adaptations.

This quiz covers fundamental concepts of biological species, including interbreeding, species classifications, and energy acquisition by organisms. It delves into examples such as lions, elephants, and dogs, exploring how species evolve and adapt within their habitats. Test your understanding of these critical aspects of biology.