Bio 1 (5)

Species Importance

Understanding species is crucial for utility, biodiversity, and classification.

Utility of Species Definition

Helps in organizing and retrieving biological information.

Biodiversity

Species are central to conservation and ecological studies.

Classification

Provides a basic rank in biological classification systems.

Biological Species Concept

Defines species as populations capable of interbreeding to produce fertile offspring.

Reproductive Barriers

Factors that prevent interbreeding between species.

Prezygotic Barriers

Barriers that occur before fertilization, preventing mating or fertilization.

Types of Prezygotic Barriers

Geographical, ecological, temporal, behavioral, mechanical, and gametic isolation.

Postzygotic Barriers

Barriers that occur after fertilization, affecting hybrid viability or fertility.

Limitations of Biological Species Concept

Not applicable to asexual organisms or where sexual reproduction is unobservable.

Morphological Species Concept

Based on structural features to determine species.

Limitations of Morphological Species Concept

Phenotypic plasticity and genetic variability can obscure true classifications.

Evolutionary Species Concept

Defines a species as a cluster of organisms representing a lineage of descent.

DNA Barcoding

Utilizes DNA extraction, PCR amplification, and DNA sequencing for species identification.

Applications of DNA Barcoding

New species discovery, biodiversity assessment, phylogenetic studies, regulation of endangered species.

Ecological Species Concept

Defines species based on their ecological niche and lifestyle.

Taxonomic Challenges

Difficulties in classifying species due to the subjective nature of classifications.

Convention on Biological Diversity

An international treaty aimed at sustaining biodiversity.

International Union for the Conservation of Nature

An organization aimed at promoting sustainable development through nature conservation.

Study of Biological Diversity

Reflects phylogeny and evolutionary history of species.

5-Kingdom Scheme

Proposed by R.H. Whittaker to classify organisms into five kingdoms.

Prokaryotes

Organisms without membrane-bound organelles, including bacteria and archaea.

Eukaryotes

Organisms with membrane-bound organelles and DNA in a nucleus.

Main Features of Bacteria

Unique rRNA sequences, no introns, presence of peptidoglycan cell wall.

Archaea Characteristics

Similar rRNA sequences to eukaryotes, presence of introns in some genes.

Kingdom Monera

Includes prokaryotic organisms, divided into bacteria and archaea.

Mode of Nutrition in Monerans

Includes photoautotrophs, chemoautotrophs, and chemoheterotrophs.

Cyanophyta

Photosynthetic bacteria known as blue-green algae.

Forms of Bacteria

Include bacillus (rod-shaped), spirillum (corkscrew-shaped), coccus (spherical).

Kingdom Protista

Mostly unicellular eukaryotes with a wide range of complexity.

Photosynthetic Protists Examples

Chlorophyta (green algae), Phaeophyta (brown algae), Rhodophyta (red algae).

Heterotrophic Protists Examples

Ciliates, sarcodines, apicomplexans, myxomycetes, oomycetes, zoomastigophorans.

Kingdom Fungi Characteristics

Heterotrophs that absorb food, with cell walls made of chitin.

Types of Fungi

Include chytrids, zygomycetes, ascomycetes, basidiomycetes.

Kingdom Plantae Characteristics

Multicellular, photosynthetic organisms with cell walls made of cellulose.

Types of Plants

Include non-vascular (moss) and vascular plants (ferns, gymnosperms, angiosperms).

Vascular Plants Examples

Pteridophytes (ferns), gymnosperms (pines), angiosperms (flowering plants).

Types of Angiosperm Fruits

Includes simple, aggregate, and multiple fruits.

Kingdom Animalia Characteristics

Eukaryotic, multicellular organisms that are heterotrophic and motile.

Porifera Characteristics

Sponges, no true tissues, asymmetrical, aquatic.

Cnidarian Characteristics

Diploblastic, radial symmetry, specialized stinging cells called cnidocytes.

Platyhelminthes Characteristics

Flatworms with acoelomate body plan, bilateral symmetry.

Nematodes Characteristics

Unsegmented roundworms with a pseudo-coelom.

Annelids Characteristics

Segmented worms with a true coelom.

Mollusks Characteristics

Soft-bodied organisms with coelom, features like a mantle.

Arthropods Characteristics

Largest phylum, jointed appendages, exoskeleton.

Echinoderms Characteristics

Marine organisms with radial symmetry.

Chordate Characteristics

Presence of notochord, pharyngeal slits, dorsal tubular nerve cord.

Subphylum Urochordates

Sea squirts, notochord present in larval stage.

Subphylum Cephalochordates

Lancelets, notochord persists throughout life.

Jawless Vertebrates Examples

Includes hagfish and lampreys.

Jawed Vertebrates Examples

Include cartilaginous fish, bony fish, amphibians, reptiles, birds, mammals.

Darwinism

Theory proposing evolution by natural selection.

Natural Selection,

Mechanism of evolution where advantageous traits increase survival and reproduction.

Genetic Drift

Changes in gene frequencies in populations due to chance events.

Bottleneck Effect

A reduction in population size leading to decreased genetic variation.

Founder Effect

Small founding population forms new species in isolated niche.

Microevolution

Evolutionary change within a species or population.

Fossil Record

Historical documentation of life on Earth with evidence of past species.

Comparative Anatomy

Study of similarities and differences in the anatomy of different species.

Homologous Structures

Similar structures in different species that have a common evolutionary origin.

Analogous Structures

Similar functions in different species but different evolutionary origins.

Comparative Embryology

Study of similarities in embryonic development among related organisms.

Molecular Biology Evidence

Related individuals show greater similarities in DNA and proteins.

Divergent Evolution

Evolutionary pattern where related species develop different traits.

Convergent Evolution

Independent evolution of similar traits in unrelated species.

Allopatric Speciation

Speciation that occurs due to physical barriers dividing populations.

Sympatric Speciation

Speciation that occurs without physical separation.

Definition of Evolution

Changes in populations over time driven by mechanisms like natural selection.

Key Terms in Evolution

Includes alleles, population, and adaptation.

History of Evolutionary Thought

Major historical figures include Anaximander, Buffon, Lamarck, Darwin, Mendel.

Mendel's Law of Segregation

Two alleles per trait segregate during gamete formation.

Mendel's Law of Independent Assortment

Different genes are inherited independently of each other.

Darwin's Theory of Natural Selection

Argument that individuals with advantageous traits are more likely to survive.

Microevolution Evidence

Artificial selection, genetic variation maintained by natural selection.

Macroevolution Evidence

Includes fossil record, comparative anatomy, and molecular biology.

Misconceptions About Evolution

Common myths include evolution is random or goal-oriented.

Key Principles of Ecosystems

Interactions and exchange of materials and energy within ecosystems.

Biotic Components

Producers, consumers, and decomposers within an ecosystem.

Energy Flow in Ecosystems

Energy captured by producers diminishes at each trophic transfer.

Trophic Levels

Hierarchical levels in an ecosystem based on feeding positions.

Biogeochemical Cycles

Pathways connecting air, water, and soil through biotic processes.

Hydrologic Cycle

Cycle involving evaporation and precipitation of water.

Nitrogen Cycle

Involves nitrogen fixation, assimilation, and bacterial processes.

Phosphorus Cycle

Cycle involving weathering of rocks and uptake by plants.

Community Definition

Changes in species composition following disturbances.

Primary Succession

Succession starting on a bare substrate after a disturbance.

Secondary Succession

Succession following a disturbance in an existing community.

Keystone Species

Species with a disproportionate impact on community structure.

Sustainable Yield

Using resources without depleting them.

Anthropogenic Impact

Effects of human activity on ecosystems.

Biodiversity Definition

Variety and variability of life on Earth.

Genetic Diversity

Variation in genes within a species.

Species Diversity

Variety of species within a habitat or ecosystem.

Ecosystem Diversity

Different ecosystems within a region.

Philippine Biodiversity

Total species and endemism data, including threatened statuses.