biology 1 Flashcards
what is biodiversity?
the number and variety of species and ecosystems on Earth
It is vital for the health and stability of ecosystems, as it enhances their ability to withstand environmental changes and disturbances.
Places such as the Tropical Rainforest and the deep ocean have high biodiversity.
→ There are three levels of biodiversity:
Genetic Diversity
Species Diversity
Ecosystem Diversity
biodiversity importance
Ecosystems with greater species diversity exhibit resilience
→ The loss of biodiversity has a negative impact on humans ..
Economically
Food source
Ecological life support
Recreational
what is Taxonomy
Taxonomy is the science of naming, identifying and classifying species.
what did Carl Linnaeus call the naming system
binomial nomenclature - meaning “two names” (in latin)
What are the two parts to a scientific name?
Genus name (first, ex:Castor)
- first letter is always uppercase
species name (last, ex:canadensis)
- first letter is lowercase and is italicized/ underlined when written by hand
Linnaeus organized the taxa from general to more specific
Kingdom → kevin
Phylum → please
Class →Come
Order →Over
Family → For
Genus → gay
Species → sex
Currently, there are SIX KINGDOMS in use for classification purposes:
Animalia
Plantae
Fungi
Protista
Eubacteria
Archaea
describe the kingdom Animalia
Multicellular with no cell wall.
Heterotrophs (feed on other animals) and eukaryotic (cells have nucleus)
Describe the kingdom Plantae
Multicellular with a cell wall & chloroplast.
Autotrophs (make their own food) and eukaryotic.
Describe the kingdom Fungi
Multicellular with a cell wall (NO chloroplast).
Heterotroph and eukaryotic.
Describe the kingdom Protista
Mostly aquatic unicellular organisms with or without a cell wall.
Heterotroph or Autotroph and eukaryotic.
Describe the kingdom Eubacteria
Unicellular with a cell wall.
Heterotroph or Autotroph and prokaryotic (no nucleus or organelles).
Describe the kingdom Archaea
Bacteria” that live in extreme conditions.
They are heterotrophs or autotrophs and prokaryotic with a cell wall.
Compare prokaryotes to eukaryotes
Prokaryotes → unicellular organisms, that don’t have a nucleus or membrane bound organelles
Eukaryotes → unicellular and small multicellular organisms with organelles; larger than prokaryotes
Describe The Domain Eubacteria characteristics
Unicellular prokaryotes (no organelles)
Plasmid (single loop of DNA; usually contains small number of genes not important for cellular function
Heterotroph or Autotroph
1 or more flagella for movement and Pilli (hair-like projections)
Cell wall
Vary in shape
Coccus (round)
Bacillus (rod shaped)
Spirillum (spiral)
Describe characteristics of Domain Archaea
Unicellular, prokaryotes
Reproduce asexually
Have unique cell membranes, cell wall, and DNA
Aerobic or anaerobic
Can live in the most extreme environments (extremophiles)
Example: dead sea (high salt concentration), marshes, hot springs, hydrothermal vents on the ocean floor, cold ocean depths, antarctic and arctic oceans
Describe characteristics of Kingdoms Eubacteria and Archaebacteria
BACTERIA
They are prokaryotes
Single-celled, organisms
Reproduce asexually by binary fission
Can be infectious (pathogens) or play key role in ecosystems
Describe the difference between obligate aerobe, obligate to anaerobes, facultative aerobes
Obligate Aerobe - need oxygen; obtained through respiration
Obligate Anaerobes - cannot survive in the presence of oxygen
Facultative Aerobes - can live with or without oxygen
How do you prokaryotes reproduce
Asexually through the process of binary Fission
The bacteria replicates its DNA then divides into two parts, producing 2 new identical daughter cells.
Reproduce rapidly
Short generation time
High mutation rate
Increases genetic diversity
what is Horizontal gene transfer?
absorb DNA from the environment for genetic recombination
what is Transformation
uptake of foreign DNA from the environment (dead bacteria)
what is Conjugation
transfer of DNA directly from one prokaryote to another
what is an Endospore?
Dormant bacterial cells formed in response to stress
→ able to survive for long periods during extreme conditions due to a hard-walled outer layer around chromosomes
E.g. freezing or high temperatures, radiation & toxic chemicals
What are Gram stain used for?
is used to divide bacteria into 2 groups
Gram positive bacteria:
Appear purple
Are common and often not pathogenic (not disease causing)
Gram negative bacteria:
Appear light pink
Tend to be pathogenic (disease causing)
