Chapter 1 Test Flashcards
What does biology mean?
The study of life
Derived from Greek: bios meaning life, logos meaning to study
Why study biology? (4)
Biotechnological advances
Medical advances
Addressing needs of a growing population
Challenges of decreasing rate of biodiversity
What does biology do? (3)
Studies characteristics and behaviors of organisms
Studies the origin and evolution of organisms
Studies the interactions of organisms and their environment
What are the traits of living things?
ORDERHEG
Order Reaction to stimuli Development Energy utilization Reproduction Homeostasis Evolutionary adaptation Growth
What are the levels of organization?
Biosphere Ecosystem Community Population Organism Groups of cells Cells Molecules
Define biodiversity
The variety of different organisms in an ecosystem, the number of individuals within each species and the variety of habitats within the ecosystem
Define species
All organisms capable of breeding freely among each other under natural conditions
Define hybridization
The cross breeding between two different species
How are organisms defined?
Defined by their species however those who reproduce asexually aren’t considered part of species therefor are defined by morphology
Define morphology
The study of physical appearance and characteristics of an organism
Define evolutionary change
A change that occurs in a species over a long period of time
Define genetic diversity
The genetic variability of each individual within the same species
Determined by the biological parents and the genetic info they pass down
Define heterotroph
An organism that consumes other living and dead organisms to gain nutrients
Define autotroph
An organism that can produce its own nutrients using natural resources
Define species diversity
Measure of diversity within ecosystems, taking into account the variety of species present and the number of individuals within each species
Define structural diversity
The variety of physical shapes and sizes in an ecosystem
Aka the variety of different habitats within an ecosystem
What is happening to the diversity of life?
What would this mean for humans?
Diversity is decreasing, species are going extinct (3 per hour as of 2017)
Loss of food supply
Loss of natural medicines
Cause disruptions in the biogeochemical cycle
Economic impact on tourism and forestry industries
What are the three components of biodiversity?
Species diversity (variety of different species within an ecosystem)
Genetic diversity (differences between living organisms within a species; genes create a unique offspring which gives the species the ability to adapt to a changing environment)
Ecosystem diversity (variety of different habitats in a particular area; the more organisms that can live there, the more diverse the ecosystem, the more stable the ecosystem)
Name things that could kill off a species (6)
Climate (natural disasters) Human activity Disease Territorial behavior Limited resources Invasive species
Why care about biodiversity?
Intrinsic value and utilitarian value
What do we get from biodiversity? (7)
Food, oxygen, clean water, medicine, ideas, aesthetics, resistance to environmental stresses and diseases
What are some threats to biodiversity? (5)
Habitat destruction Pollution Global climate change Species introduction Exploitation
Define biological classification
The systematic grouping of organisms into biological categories based on physical and evolutionary relationships
Why do we classify organisms?
- to represent similarities and proposed relationships
- biologists can be certain they’re discussing the same organism
- common names don’t say how they’re related or classified
- common names could be misleading
Define taxonomy
The science of identifying and classifying all organisms (living and fossilized)
How did they classify organisms in the past?
A hierarchy that was flawed due to its unchanging policy and the fact that animals were always above plants
Explain the Linnaean system
Species were grouped into taxonomic ranks (taxons) which included 7 major levels (Kingdom, Phylum, Class, Order, Family, Genus, Species)
Similar species grouped into genera, similar genera into families, similar families into orders, orders into classes, classes into phyla, and phyla into kingdoms
What is a dichotomous key?
A series of branching, two-part contrasting statements used to identify organisms
An easy method to identify them but not perfect
Describe the problem with using this system (using physical characteristics and similarity to group organisms) in modern taxonomy
Using similarity as the basis for grouping has challenges as some features are difficult to observe (inner characteristics)
What is binomial nomenclature
A two-word naming system for species whereby species are assigned a genus name followed by a species name which form the official universally accepted name (ex Rosa canina)
Define evolution
The scientific theory that describes changes in species over time and their shared ancestry
Theory states all living things are descended from a common ancestor; some species more closely related than others
Define phylogeny
The study of the evolutionary relatedness between and among species
define evolutionary classification
Grouping organisms together based on their evolutionary history, shown through phylogenic trees
Not just looking at physical characteristics
Define phylogenetic tree
A diagram depicting the evolutionary relationships between different species or groups
Groups of organisms in a tree are descendants of one or more common ancestors
Species grouped into clades
Define clade
A taxonomic group that includes a single common ancestor and all its descendants
Can be small or large
What is the one challenge of evolutionary classification and phylogenetic trees?
Uncovering relations going back millions of years requires detailed analysis of fossil and genetic evidence
What does modern taxonomy use to identify species?
DNA
DNA barcoding: uses DNA tech to create a DNA profile of every species in the form of a barcode
Eventually researches will have a handheld device to immediately identify species with a small DNA sample
What are the five phylogenetic Kingdoms?
Monera (Eubacteria and Archaeabacteria)
Protista
Fungi
Plantae
Animalia
Define cladogram
Diagram that shows the evolutionary relationships among a group of organisms
Based on characteristics only observable in existing species
What are phylogenies determined on?
Embryological development (similarities in embryos)
Homologous structures (similar body structure)
Genetic similarities (similar DNA and RNA)
What are molecular clocks?
A tool used to calculate the timing of evolutionary events in an epoch scale
Relies on mutations to mark time
Measures the number of mutation which accumulate over time in different species (can determine when two species diverged)
What are domains?
Most inclusive taxonomic category (larger than a kingdom)
Eukarya, Bacteria, Achaea
Compare prokaryotes and eukaryotes
Size, cell, organelles, oxygen, wall
P: small; rigid cell wall; single-celled; no membrane bound organelles; may not need O2; cell walls often contain peptidoglycan
E: larger; flexible cell wall; multi-cellular; membrane-bound organelles; usually need O2; cell walls when present are simple
Describe each kingdom (4 each)
Eubacteria: prokaryote; cell wall w/ peptidoglycan; unicellular; auto or hetero
Archaeabacteria: prokaryote; no peptidoglycan; unicellular; auto or hetero
Protista: eukaryote; some have cell walls w/ cellulose other w/ chloroplasts; most unicellular; auto or hetero
Fungi: eukaryote; cell wall w/ chitin; most multicellular; hetero
Plantae: eukaryote; cell walls of cellulose + chloroplasts; multicellular; auto
Animalia: eukaryote; no cell walls or chloroplasts; multicellular; hetero
