Diversity Flashcards
Define diversity
The condition of being different from one another
Which animal is called different names in California, Florida, Mexico/South America, and Appalachia?
Mountain lion / panther / puma / catamount
How many species have been identified and how many are thought to exist?
2 million and 20 million
What are the three working species concepts?
Morphological, biological, phylogenetic
Describe the morphological species concept
Focuses mainly on morphology (body shape, size, and structural features of an organism)
Describe the biological species concept
Describes species as a group of organisms that have similar characteristics, can be interbred in nature, and produce fertile offspring
Describe the phylogenetic species concept
Focuses on the phylogeny (evolutionary history) of organisms. When a prehistoric species branches into two species over time, it becomes two distinct phylogenetic species
Which is the most practical species concept and the one we use in class?
Biological species concept
What types of evidence help us determine how species have evolved and are related?
Anatomical, physiological, DNA
Describe anatomical evidence of relationships
Similar anatomical structures imply that there is likely a shared ancestor
Describe physiological evidence of relationships
Similarities in the physical and chemical functions of organisms (how they work) including their biochemistry and internal processes
Describe DNA evidence of relationships
Species that are more closely related (therefore sharing a closer ancestor) tend to have great similarities in their DNA
What is the complete human classification?
Kingdom: Animals
Phylum: Chordates
Class: Mammals
Order: Primates
Family: Hominids
Genus: Homo
Species: Homo sapiens
Define taxonomy
The branch of biology that identifies, names, and classifies species. Pioneered by Carl Linnaeus
What is the classification hierarchy from most general to most specific?
Domain, kingdom, phylum, class, order, family, genus, species
Describe binomial nomenclature
Scientific name composed of the genus and species. Both terms are italicized and the genus is capitalized
Define phylogenetic tree
A branching diagram used to show the evolutionary relationships among species
Define dichotomous key
A tool used to identify unknown organisms, consisting of a series of anatomical questions that contain two possible choices
What are the possible domains under which all organisms fall?
Archaea, bacteria, eukarya (contains kingdoms protista, fungi, plantae, animalia)
List the two types of cells
Prokaryotic and eukaryotic
Describe prokaryotic cells
Meaning “before the nucleus”, it has no membrane-bound nucleus, a simpler internal cell structure, and is usually smalle, around 0.1-10µm
Describe eukaryotic cells
Meaning “true nucleus”, it has a membrane-bound nucleus, more complex internal cell structure, and is usually larger, about 10-100µm
Give examples of prokaryotic cells
Bacteria, blue-green algae
Give examples of eukaryotic cells
Plant cells, animal cells
Which domain includes all kingdoms made of organisms with eukaryotic cells
Eukarya
Which two domains are both prokaryotic but separate due to great cellular and genetic differences?
Bacteria and archaea
What are the six kingdoms?
Bacteria, archaea, protista, plantae, fungi, animalia
What characteristics are used to classify kingdoms?
Number of cells (unicellular or multicellular), cell wall material (if present), nutrition (autograph or heterotroph), primary means of reproduction (asexual or sexual)
Define autotroph
An organism that captures energy from sunlight or abiotic substances
Define heterotroph
An organism that obtains energy by consuming other organisms
What are the characteristics of all living things
Are made of cells, obtain and use energy, grow and develop, produce offspring similar to themselves, respond to their environment, adapt to their environment
Define virus
A microscopic particle capable of reproducing only within living cells. It contains strands of DNA and RNA surrounded by a protective protein coat called a capsid
What is the name of the protective protein coat which surrounds the DNA and RNA strands in viruses?
Capsid
Are viruses alive?
They are considered lifeless because they are not capable of living independently outside of cells (a host). Furthermore, it has no cellular structure, cytoplasm, organelles, or cell membranes, no respiration, and lacks the other life processes found in living cells
Which virus is known as the “eater of bacteria”?
Bacteriophage
Describe bacteriophages
A type of virus which infects and destroys bacterial cells. It is composed of nucleic acid, capsid, tubes, end plate, and spikes
Describe how viruses reproduce
They do not reproduce by cell division. They undergo replication within a host cell (prokaryotic or eukaryotic) and they use the host cell to produce multiple copies of themselves
What are the two viral reproductive cycles?
Lytic cycle, lysogenic cycle
Describe the lytic cycle
The virus attaches to a host cell. It injects its DNA or RNA into the cell cytoplasm. The viral DNA directs the host cell to make viral parts (Ex. Capsids, viral proteins, etc.) which are assembled to make new viruses, then lysis is triggered (host cell bursts and dies) releasing the newly-made viruses. This process takes just 25-45 minutes and hundreds of new viruses are made
Review a diagram of the lytic cycle
Describe the lysogenic cycle
Attachment and injection similar to lytic cycle, but instead of taking control the viral DNA becomes part of the host DNA. The viral DNA that has become part of the host chromosome is referred to as a provirus. When the host replicates, the viral DNA gets passed on to its daughter cell, and it stays dormant until some environmental change triggers the lytic cycle
What is another name for the lysogenic cycle
Dormant cycle
Review a diagram of the lysogenic cycle
Describe biotechnology
Refers to technology we can use to change the genetic information of an organism. We can use viruses to do this and its uses include gene therapy (changing a faulty gene in a person), agriculture (producing larger and more resilient crops), and vaccines
How are vaccines created?
By taking dead, weakened, or inactivated pathogens (disease causing agents) and injecting them into an organism
How do vaccines work?
Upon injection, an organism’s immune system will learn how to fight the harmless pathogen in the vaccine so that if the active/live pathogen is ever encountered, th immune system will be able to fight it
What was the first vaccine made?
Smallpox
How was the smallpox vaccine effective?
Smallpox was deadly and nearly identical to the harmless cowpox disease. Being infected with cowpox granted immunity to smallpox
Describe prions
Infectious proteins that cause damage to nerve cells in the brain. They are likely incorrectly folded proteins. When it comes into contact with a cell containing the normal form of the protein, the prion converts the normal protein into the prion version
What is the term for infectious proteins that cause damage to nerve cells in the brain?
Prions
Which protein causes mad-cow disease?
Prions
What are the two oldest groups of organisms on earth?
Bacteria and archaea
What group of organisms produces nearly half the oxygen found in the atmosphere?
Bacteria
Which group of organisms can live in extreme environments that are toxic to almost all other living things?
Archaea
Of which group of organisms are there more cells in your body than human cells?
Bacteria
What is another name for bacteria?
Eubacteria
What is another name for archaea?
Archaebacteria
List differences between archaea and bacteria
Significantly different genes, chemical differences in the RNA, cell membranes have different structures and chemical compositions, archaea tend to be adapted to live in extreme environments (extremophiles)
What are the most common morphological forms in bacteria and archaea?
Coccus (round), bacillus (rod-shaped), spirrilum (spiralled or bent)
What are alternative morphologies to bacteria and archaea?
Bacteria: cubes or pyramids
Archaea: plates or rectangles
What prefix is used to describe the configuration of one bacterium?
Mono-
What prefix is used to describe the configuration of two aggregated/attached bacteria?
Diplo-
What prefix is used to describe the clumped configuration of bacteria?
Staphylo-
What prefix is used to describe the chain configuration of bacteria?
Strepto-
How do species in archaea and bacteria obtain energy?
By consuming other organisms (heterotroph), carrying out photosynthesis (autotroph), or from inorganic compounds such as hydrogen sulfide or iron (chemoautotroph). Certain species of archaea can also undergo methanogenesis (the production of gas methane as a result of digestion)
Describe the differences in habitats of archaea and bacteria
Both can live in aerobic (oxygen-rich) and anaerobic (without oxygen) environments. Archaea can live in extreme environments (extremophiles) while bacteria live in more moderate habitats (mesophiles)
What are the types of extremophiles?
Thermophile, acidophile, halophile
Which type of extremophiles lives in extremely hot temperatures?
Thermophile
Which type of extremophiles lives in extremely acidic environments?
Acidophile
Which type of extremophiles lives in extremely salinous environments?
Halophile
Why do bacteria and archaea not reproduce through mitosis or meiosis?
They do not have a nucleus
How do bacteria and archaea reproduce?
Prokaryotes reproduce through binary fission, a form of asexual reproduction, and some bacteria reproduce through conjugation
Describe binary fission
The cell grows, makes a copy of its original single chromosomes, elongates, then separates into two smaller, genetically identical cells
Describe conjugation
One cell links to another, thereby transferring their genetic information. This produces cells with new genetic combinations and results in organisms that are better adapted to changing conditions
How are archaea related to biotechnology?
They have enzymes that do not break down under extreme temperatures. This is used in DNA analysis to diagnose diseases and would decrease production cost of new technology
How are bacterial helpful?
They can recycle dead materials into nutrients, be used in bioremediation (cleaning up pollution naturally), be probiotic agents which help maintain health and prevent diseases, and be used in industry to produce beer, wine, vinegar, and more
How can bacteria be harmful?
They produce toxins which cause symptoms in humans (Ex. Walkerton tragedy in which rain washed cow manure into well water, giving people a deadly strain of E. Coli)
List characteristics of protists
60,000+ species, eukaryotes, generically unicellular but can be multicellular (algae), 10µm - 60m, grouped mainly because they don’t fit into other kingdoms
What are the three major groups of protista?
Animal-like protista (protozoa), plant-like protista (algae), fungi-like protista (slime moulds and water moulds)
Describe animal-like Protista
Heterotrophs classified into four phyla based on their locomotion: amoeba, ciliates, flagellates, and sporozoans
Describe amoeba
Use temporary extensions of the cytoplasm called pseudopods (“false feet”)
Describe ciliates
Have short, hair-like projections called cilia
Describe flagellates
Have a long, hair-like tail called a flagellum that whips side to side
Describe sporozoans
Parasites that take the nutrients they need from their hosts
Describe plant-like protista
Simple, aquatic, chloroplast-containing organisms. Autotrophs that photosynthesize and range from single cells to giant seaweeds. They are classified into six phyla based on their different types of chlorophyll and pigments
Describe fungi-like protists
Heterotrophs that absorb nutrients from other organisms and produce spores
List the characteristics of animalia
Eukaryotic, multicellular, no cell walls, heterotrophic, usually mobile (in at least one stage of their life), reproduce sexually and produce an embryo which undergoes stages of development
What are the ways in which we classify animals?
Presence of a backbone, levels of organization, number of body layers, movement, symmetry and body plan, segmentation, body cavity, reproduction
What are characteristics with respect to the presence of a backbone in animalia?
Vertebrates have a backbone to protect the spinal cord whereas invertebrates do not
What are characteristics with respect to the levels of organization in animalia?
Differences in structure, function, and development
What are characteristics with respect to the number of body layers in animalia?
One to three
What are characteristics with respect to movement in animalia?
Active or sessile
What are characteristics with respect to symmetry and body plan in animalia?
Asymmetrical (no plane of symmetry), radial (symmetrical about any plane with a central axis), or bilateral (symmetrical in one plane)
What are characteristics with respect to segmentation in animalia?
Division of the body into repetitive sections
What are characteristics with respect to the body cavity in animalia?
Present or absent
What is another name for the body cavity?
Coelom
What are characteristics with respect to reproduction in animalia?
Asexual or sexual, internal or external fertilization
List the eight main phyla of animalia
Porifera, cnidaria, platyhelminthes, annelida, mollusca, echinodermata, arthropoda, chordata
Describe the phylum echinodermata
Includes sea stars, sea urchins, sea cucumbers, and sand dollars. Marine animals with radial symmetry, spinal endoskeletons, and tube feet
Describe the phylum arthropoda
Largest phylum by far, divided into five main classes. Have legs made of jointed skeletons, segmented body with an exoskeleton, and organ systems. They are also coelomate
Describe the phylum chordata
Two common features extending the length of the body in all chordates: a notochord (a flexible, rod-like structure that is eventually replaced by the spine in vertebrates) and a dorsal nerve cord. Most also have endoskeletons of bones or tough cartilage, and many are tetrapods
Describe the class osteichthyes and chondrichthyes
Former contains the vast majority of fish on Earth and is made of bone. Latter are fish made of cartilage. Most have jaws and some have a swim bladder for vertical movement
Describe the class amphibia
Amphibians such as toads, frogs, and salamanders. Evolved from bony fish and are tetrapods. Live both in water and on land for a portion of their lives. Fertilization is external
What are the three orders of the class reptilia?
Lizards and snakes, turtles, and crocodiles
Describe the class reptilia
Not dependant on water because of body scales that prevent dehydration, use lungs for gas exchange, fertilization is internal
Describe the class aves
Birds and likely descendants of dinosaurs. Tetrapods but great differences in their front limbs. Most have hollow bones that are light for flyinh
Describe the class mammalian
Have mammary glands that secrete milk to nourish young, have hair, have four-chambered hearts and highly-developed brains
Describe the group monotremes
Egg-laying mammals of which the duck-billed platypus and echidna are the only living examples
Describe the group marsupials
Pouched mammals that have a short gestation period (the amount of time offspring develop in the uterus)
Describe placental mammals
Have a placenta, have great diversity in species and structure, include beats, bats, whales, and humans
