Systematics + Properties of Life

Systematics

Study of biological diversity and evolutionary relationships of organisms

Taxonomy and phylogenetics

Main parts of systematics

Classification Hierarchy

Organisms are grouped in a hierarchical system

Taxonomy

Science of naming, describing, and classifying organisms based on shared characteristics and evolutionary relationships

Taxon

Any group of organisms given a formal taxonomic name

Domain

Groups organisms based on cell type and genetic makeup

Archaea

Type of domain that includes organisms that are prokaryotic and live in extreme environments

Bacteria

Type of domain that includes organisms that are prokaryotic and are common everywhere

Eukarya

Type of domain that includes organisms that are eukaryotic with nucleus

Kingdom

Groups organisms with similar basic features

Animalia

Multicellular, heterotrophic

Plantae

Multicellular, autotrophic

Fungi

Absorbs nutrients, decomposers

Protista

Single-celled eukaryotes

Bacteria / Eubacteria

Prokaryotic bacteria

Archaebacteria

Ancient prokaryotes

Phylum

Groups organisms with same major body plan

Class

Organisms in a phylum are divided into these

Order

Groups related families

Family

Groups closely related genera

Genus

Group of very closely related species

Species

• Smallest and most specific rank

  • Group of organisms that can interbreed and produce fertile offspring

1. Domain – Eukarya

2. Kingdom – Animalia

3. Phylum – Chordata

4. Class – Mammalia

5. Order – Primates

6. Family – Hominidae

7. Genus – Homo

8. Species – Homo sapiens

Taxonomic Rank of Humans

Binomial Nomenclature

System of giving organisms a two-part scientific name

Genus + species

Composition of scientific name

Phylogenetics

Study of the evolution, history, development, and relationships among groups of organisms

Cladistics

Method of classifying living organisms based on common ancestry

Cladograms

Diagram used in cladistics to show evolutionary relations between groups of organisms

Clade

Group of organisms that includes an ancestor and all its descendants

Node

Point on a cladogram where a single lineage splits into two or more lineages

Morphological Characteristics

Physical traits

Molecular Characteristics

DNA, RNA, Protein structures

Behavioral Characteristics

Specific patterns of behavior that are inherited

Ancestral Traits

Characteristics inherited from a distant common ancestor and shared among a group

Derived Traits

New, specialized characteristics that evolved in a specific lineage after separating from that ancestor

Apomorphy

Derived trait that evolved from an ancestral condition

Plesiomorphy

Ancestral trait inherited from a distant ancestor

Autapomorphy

Derived trait unique to a single taxon or lineage

Synapomorphy

Shared derived trait inherited from the most recent common ancestor of a group

Homoplasy

Trait that appears similar in different organisms but did not come from a common ancestor

Convergent Evolution

How does homoplasy happen

Phylogenetic Tree

Diagram that represents evolutionary relationships among organisms

Monophyletic Group

Group that includes an ancestor and all its descendants; also called a clade

Paraphyletic Group

Group that includes an ancestor but not all of its descendants

Polyphyletic Group

Group that does not include the most recent common ancestor of all members

Homologous Structure

Structures in different species that are similar in origin but different in function

Analogous Structure

Structures in different species that are different in origin but similar in function

Hierarchy of Organization

Represents the levels of biological complexity, from the smallest units to entire planet or simplest to most complex

Atom

Basic unit of matter

Molecule

Group of atoms bonded together

Organelle

Functional mini-organs inside a cell

Cell

Basic unit of life

Tissue

Group of similar cells working together to perform a specific function

Organ

Different tissues working together

Organ System

Group of organs working together

Organism

Individual living thing

Population

Group of individuals of the same species living in a specific area

Biological Community

Different populations interacting in an area

Ecosystem

All living organisms plus non-living environment

Metabolism

Total of all chemical reactions in an organism

Metabolism

Ability of an organism to produce its own energy

Adenosine Triphosphate (ATP)

Primary energy source for cellular energy use and storage

Anabolism

Small molecules built into large ones (uses energy)

Catabolism

Large molecules broken down into small ones (releases energy)

Photosynthesis in Chloroplast

Metabolism for Plants

Cellular Respiration in Mitochondria

Metabolism for Animals

Response to Environment

How an organism reacts to an internal or external changes (stimuli)

Tropism

Growth toward or away from a stimulus

Phototropism

Growth toward or away from light

Geotropism

Growth toward or away from gravity

Thigmotropism

Growth toward or away from touch

Homeostasis

Ability to keep a stable internal condition

Negative Feedback

Works to reverse a change to bring the system back to a set point

Positive Feedback

Works to amplify or increase a change

Reproduction

Process by which new organisms ("offspring") are produced from their "parents”

Asexual Reproduction

Only one parent, resulting in offspring genetically identical to the parent

Binary Fission

Used by prokaryotes; the cell replicates its DNA and splits into two equal parts

Mitosis

Used by eukaryotes for growth, tissue repair, and asexual reproduction in single-celled organisms; one cell divides into two identical daughter cells

Sexual Reproduction

Involves two parents and the fusion of specialized cells, leading to genetic variation in offspring

Meiosis

Specialized type of cell division that reduces chromosome number by half to create gametes (sperm and egg cells)

Fertilization

Process where sperm and egg join to form a zygote, restoring full number of chromosomes

Growth

Increase in physical dimensions (e.g., height, weight, volume) or dry mass

Development

Progression of an organism through its life cycle, involving changes in form, function, and complexity

Evolutionary Adaptation

Process by which species change over generations to better fit their environment through natural selection