DAT Diversity of Life Flashcards
Independent metabolism
viruses lack this and so are not considered truly ‘alive’
Ability to self-replicate
this determination does not include the ability to produce gametes!
How many main criteria in determining the living vs the non living
2
The taxonomic ranks, from most general to most specific, are
domain, kingdom, phylum, class, order, family, genus, species.
Way to remember the taxonomic levels…
King Philip came over for grape soda
Systematics
The study of evolutionary relationships among organisms.
Prokaryotic cells have a..
single chromosome that is short. They have circular DNA that usually does not have histones.
The flagella of prokaryotes consist of
chains of the protein flagellin
Autotrophs
manufacture their own organic materials. They use light (photo) or chemicals (chemo) such as H2S, NH3, NO, and NO3
Heterotrophs
obtain energy by consuming organic substances produced by autotrophs
Parasites
obtain energy from living
tissues of hosts
Saprobes (saprophytes)
obtain
energy and feed from dead, decaying matter which contribute to organic decay. Decomposers are slightly different in that they break down dead and decaying matter
Obligate aerobes
must have O2 to live
Obligate anaerobes
require the
absence of O2 to live; they cannot live with the presence of oxygen. They are unable to detoxify some products of oxygen metabolism (e.g., H2O2 would be toxic to them)
Facultative anaerobe
grows in the presence of O2, but can switch to anaerobic metabolism when O2 is absent
Archaea
prokaryotes but they differ from bacteria. Archaea are non-pathogenic.Archaeal cell walls contain various polysaccharides,
Similarities between eukaryotes and archaea
- DNA of both archaea and eukaryotes
are associated with histones, while
bacterial DNA is not - Ribosome activity is not inhibited by
antibiotics streptomycin and chloramphenicol, unlike bacteria
Methanogens
Group of archaea: obligate anaerobes that
produce CH4 as a by-product of obtaining energy from H2 to fix CO2
Extremophiles
Group of archaea: live in extreme enviroments
Halophiles (salt lover)
Group of extremophiles: they live in high salt concentration environments. Most are aerobic and heterotrophic; others are anaerobic and photosynthetic with bacteriorhodopsin
Thermophiles (heat lover
Group of extremophile:are sulfur-based chemoautotrophs that live in very hot places
Other extremophiles
live in high acid/base/pressure environments
Domain Bacteria
Bacteria are distinct from archaea and eukaryotes because of certain features. Bacteria have cell walls that have peptidoglycan, which is a polymer of monosaccharides with amino acids. Bacterial DNA is not associated with histones, and ribosome activity is inhibited by antibiotics like streptomycin and chloramphenicol.
Classification of bacteria
- Mode of nutrition/how they metabolize resources
- Ability to produce endospores 3. Means of motility 4. Shapes 5. peptidoglycan cell wall
- Means of motility (bacteria)
flagella, corkscrew motion, or gliding through slime material
Ability to produce endospores (bacteria)
these are resistant bodies that contain DNA and small amounts of cytoplasm surrounded by a durable wall
Shapes (bacteria)
cocci (spherical), bacilli (rod- shaped), spirilla/spirochetes (spirals
Peptidoglycan cell wall
gram-positive bacteria have thick peptidoglycan cell walls. Gram-negative bacteria have thin peptidoglycan covered with lipopolysaccharides. Peptidoglycan contains amino sugars
Teichoic acids
these acids on the cell walls of bacterium are used as recognition and binding sites by bacterial viruses that cause infections.
Common groups of bacteria
cyanobacteria, chemosynthetic, nitrogen fixing, spirochetes,
cyanobacteria
they are
photosynthetic and contain an accessory pigment called phycobilins. Some have specialized cells called heterocysts that produce nitrogen-fixing enzymes
Chemosynthetic
these bacteria are autotrophs. Some are nitrifying bacteria, which are able to convert nitrite to nitrate
Nitrogen-fixing
these bacteria are heterotrophs that fix N2. They live in the nodules of plants, and this is a form of mutualism because the bacteria provides useable nitrogen for the plant, while the plant gives the bacteria a home and fixed carbon to utilize
Spirochetes
coiled bacteria that move with a corkscrew motion. There is internal flagella between cell wall layers
Domain Eukarya (4 Kingdoms)
This domain has multiple relevant kingdoms. The first kingdom is Protista. This is an artificial kingdom used mainly for convenience and is poorly understood. Features shared by two or more groups may represent convergent evolution, and most protists are unicellular. They are generally classified by means of locomotion, and all protists live in moist environments.
Algaelike (plant-like) (domain eukaryotic)
these protists all obtain energy by photosynthesis. All have chlorophyll a, and some have accessory pigments. They are mainly categorized by the form of carbohydrate used to store energy, the number of flagella, and the makeup of the cell wall
Euglenoids (algae like)
have one to three flagella at the apical end. Instead of a cellulose cell wall, euglenoids have thin, protein strips called pellicles located below the cell membranes. They are heterotrophic in the absence of light, and some have eyespots that permit phototaxis (ability to move in response to light).
Dinoflagellates (algae like)
have two flagella. One is posterior, while the second flagellum is transverse and rests encircling the mid-groove perpendicular to the first flagellum.
Diatoms (algae like)
have tests (shells) that fit together like a box with a lid, and they also contain SiO2 (silica)
Brown algae (algae like)
multicellular and have flagellated sperm cells. They look like giant seaweed.
Rhodophyta (algae like)
red algae and have red accessory pigments called phycobilins. They are multicellular and their gametes do not have flagella
Chlorophyta
green algae and have both chlorophyll a and b. They have cellulose in their cell walls, and they store energy in the form of starch. Some species have isogamous gametes (both sperm and egg are equal in size and motile), some are anisogamous (sperm and egg differ in size), and others can be oogamous (large egg cell remains with the parent and is fertilized by small, motile sperm).
Protozoa (animal-like) (protist type)
these protists are heterotrophs. They consume living cells or dead organic matter, and are unicellular eukaryotes
Rhizopoda (animal like)
amoebas that move by extensions of their cell body called pseudopodia. They encircle their food using phagocytosis
Foraminifera (animal like)
aka forams, have tests(shells) usually made of calcium carbonate. Sediments of foraminifera indicate oil deposits
Apicomplexans (animal like)
parasites of animals. They have an apical complex (complex of organelles located at an end of the cell) and no physical motility. They form spores which are dispersed by hosts that complete their life cycle. Malaria is caused by a sporozoan
Ciliates (animal like)
use cilia for moving and other functions. They have specialized structures: mouths, pores, contractile vacuoles (H2O balance), two kinds of nuclei (largemacronucleus and several small nuclei). They are the most complex of all cells. An example of a ciliate is the paramecium.
Amoebas
genus of protozoa, and are shapeless and unicellular. They move via pseudopods
Fungus-like protists
resemble fungi and form filaments/spore-bearing bodies like fungi do
Cellular slime molds
have fungus-
like and protozoa-like characteristics. The spores germinate into amoebas which feed on bacteria. When no food is available, amoebas aggregate into a single unit slug.
Plasmodial slime molds
grow as a single, spreading mass (plasmodium) that feeds on decaying vegetation.
What is the difference between plasmodial and cellular slime molds?
Both have a stalk and release haploid spores which haploid amoeba cells emerge from. In plasmodial slime molds, the amoeboid cells fuse and form a diploid zygote.
Oomycota
are water molds, mildews, and white rusts. They are either parasites or saprobes, which receives nutrition from dead and decaying organic matter
Kingdom Fungi
Fungi grow as filaments called hyphae, and mycelium is a mass of hyphae. Cell walls contain chitin (N- containing polysaccharide). Some fungi have septum which divide filaments into compartments containing a single nucleus.
Fungi without septa
coenocytic
Stages of fungi sexual reproduction
Plasmogamy, Karyogamy, Meiosis
plasmogamy
fusing of cytoplasm of cells from two different fungal strains to produce a single cell without fusing of the nuclei. The resulting cell has a pair of haploid nuclei, one from each strain, and is now called a dikaryon. Dikaryotic hypha is hypha containing dikaryon
Karyogamy
fusing of two haploid nuclei of a dikaryon to form a single diploid nucleus
Meiosis
meiosis of diploid nucleus restores haploid condition. The daughter cells develop into haploid spores which germinate into haploid hyphae (has 1 fungal strain) and then merge into dikaryons to repeat the cycle
Means of asexual reproduction (fungi)
Sporangiospores, Conidia,
Sporangiospores
spores produced in sac-like capsules called sporangia that are each borne on a stalk called a sporangiophore
Conidia
a type of asexual spore formed at the tips of specialized hyphae and are not enclosed inside sacs. Hyphae bearing conidia are called conidiophores
group names with the suffix –mycota
denote a division
Group names with the suffix –mycete
denote classes
Six fungus groups
Zygomycota, Glomeromycota, Ascomycota, Basidiomycota, Deuteromycota, Lichens
Zygomycota
these fungi lack septa, except the filaments bordering reproductive filaments.
Glomeromycota
these fungi lack septa and do not reproduce sexually. They form mutualistic associations with roots of plants, and this relationship is called a mycorrhiza.
Ascomycota
these fungi have septa and reproduce sexually by producing haploid ascospores
Basidiomycota
they have septa and reproduce sexually by producing haploid basidiospores
Deuteromycota
they are imperfect fungi and an artificial group because they have no known sexual reproductive cycle.
Lichens
lichens are symbiotic associations between fungi and algae or cyanobacteria.
Miscellaneous Fungal Genus
Rhizopus, Candida, Saccharomyces cerevisiae
Rhizopus
fungal pathogen that
is involved with food spoilage. It is an obligate parasite because it depends on its host for survival. Rhizopus stolonifer is commonly known as the black bread mold, and is also a type of Zygomycota
Candida
involved in infections of mucous membranes
Saccharomyces cerevisiae
a type of yeast that is involved in fermenting sugars to alcohol
Adaptations for survival on land(plantae)
Dominant diploid generation, cuticle, vascular system, sperm dispersal, antrhophyta, seasonal variations
anthophyta
division of plants otherwise known as angiosperms, they have their gametophytes enclosed and protected inside an ovary
Major seedless plant divisions
bryophytes, lycophyta, pterophyta,
Bryophytes
includes
the mosses, liverworts, and hornworts. Gametes are produced in gametangia (protective structures) on gametophytes
Lycophyta
can also be called a part of the seedless vascular plants and includes clubmosses, spike mosses, and quillworts, which are herbaceous.
Pterophyta
this division is also called seedless vascular plants and has three groups: ferns, horsetails, and whisk ferns.
Seeded vascular plant divisions
Microsporangium, Megasporangium, Coniferophyta, angiosperms
parts of an angiosperm
Pistil, stamen, petals
Microsporangium
produces numerous microspore mother cells, which divide by meiosis to produce four haploid cells a.k.a. microspores.
Megasporangium
the nucellus produces the megaspore mother cell. After undergoing meiosis, four haploid cells are created but only one survives to become the megaspore (
Coniferophyta
a.k.a. gymnosperms, meaning naked seeds. These plants are cone- bearing and include the pines, firs, spruces, junipers, redwoods, and cedars. They have pollen-bearing male cones and ovule-bearing female cones
Anthophyta (angiosperms)
these are flowering plants which include fruits, maple, oaks, grass, etc., and are the dominant land plant form. The flower is the reproductive structure of an angiosperm.
Kingdom Animalia
This kingdom is monophyletic, meaning all the species can be traced back to one common ancestor. The kingdom is very diverse, but its members do share these common characteristics:
* Multicellular
* Heterotrophic
* Dominant diploid generation
* Motile at some part of their life cycle * 2-3 layers of tissues form during
embryonic development
Body symmetry
Animals can have different types of symmetry. Radial symmetry means the organisms have a top and bottom but no distinct left and right sides; they have circular body patterns. Animals with bilateral symmetry have a distinct left and right side. When divided by a sagittal plane, the left and right sides are mirror images.
Cephalization
animals with bilateral symmetry can have a higher concentration of nerve tissue located at the anterior end as organisms increase in complexity (e.g., brains are highly developed and have sensory organs)
Gastrovascular cavity
this is the digestive system. The gastrovascular cavity has one opening and is sac-like with limited processes. A digestive tract has two openings with specialized activities as food travels through
Tissue complexity
eumetazoans are organisms with true tissues that are organized into germ layers. Diploblastic organisms have two embryonic cell layers. Triploblastic organisms have three embryonic cell layers, which, from superficial to deep, are called the ectoderm, the mesoderm, and the endoderm.
Coelom
Animals can be classified as either acoelomate, pseudoceolomate, or coelomate. The coelom is derived from the mesoderm, and is a fluid-filled cavity that cushions the internal organs.
Segmentation
some organisms have segmented body structures. The segmentation can be repetitive or is sometimes specialized. Segmentation can be seen in arthropods, annelids, and chordates
Protostomes and deuterostomes
cleavages/cell divisions in a zygote’s early development is different depending on the type of organism. The archenteron is the primitive gut that forms during gastrulation in the developing blastula. It develops into the digestive tract of an animal, and its opening will then develop into the mouth or the anus depending on the type of organism. Protostomes are organisms that develop mouth first, and deuterostomes are organisms that develop anus first
Porifera
known as sea sponges, these organisms are parazoans. They feed by filtering water through the sponge wall of flagellated cells called choanocytes. Sea sponges are sessile, meaning they cannot move. Porifera are used in the development and research of antibiotics
Cnidaria
these include the hydrozoans, jellyfish, sea anemones, and corals. Cnidarians have two body forms: the floating, umbrella-shaped body with tentacles called the medusa, and the sessile cylinder-shaped body with rising tentacles called the polyp. Some cnidarians alternate between the medusa and polyp forms in their life cycle. Cnidarians are carnivores, and they have tentacles to capture prey
Platyhelminthes
there are three types of acoelomate flatworms to know: planarians, flukes, and tapeworms.
Planarians
free-living flatworms and are carnivores in marine or freshwater bodies of water.
Flukes
internal/ external animal parasites that suck tissue fluids and blood.
Tapeworms
internal parasites that often live in the digestive tract of vertebrates. Tapeworms appear segmented, but these segments, called proglottids, only develop secondarily for reproduction, and so tapeworms are not considered to be truly segmented animals.
Nematoda
otherwise known as roundworms and are pseudocoelomate with a complete digestive tract. Nematodes are free-living soil dwellers that help decompose and recycle nutrients.
Rotifera
these are multicellular organisms with specialized organs enclosed in a pseudocoelom. They have a complete digestive tract and are filter- feeders. Rotifera are also capable of parthenogenesis, which is a type of asexual reproduction
Mollusca
includes snails, octopus, squids, and bivalves. Octopus have highly developed nervous systems with complex brains. Bivalves have two- part shells and include organisms like clams and mussels. Most squids have small and internal shells, but octopus have no shells. Mollusks have coelomate bodies, complete digestive tracts, and usually have open circulatory systems with internal cavities called the hemocoel.
classes of mollusca
class Gastropoda, Cephalopoda, bivalvia
Class Gastropoda
largest molluscan class and includes animals such as slugs and snails, characterized by a single shell
Class Cephalopoda
this class includes the octopus and squid. They have high O2 demand, giant nerve fibers, and closed circulatory systems
Class Bivalvia -
this class includes clams, mussels, scallops, and oysters
Annelida
these are segmented worms which include leeches, earthworms, and polychaete worms.
Arthropoda
this groups includes spiders, insects, and crustaceans. Arthropods have jointed appendages which allows them to be successful, have well-developed nervous systems, specialized body segments, and exoskeletons made of chitin
classes of arthropoda
class insecta, class arachnida, class crustacea
class insecta
these organisms have three pairs of legs, one pair of antennae, and spiracles. Spiracles are tracheal tubes used for breathing. There are more insect species than any other class on earth
Class Arachnida
these animals have four pairs of legs and “book lungs,” which are respiratory structures that look like sheets of a book. Arachnids include spiders and scorpions. Arachnids do not have antennae
Class Crustacea (subphylum)
crustaceans have segmented bodies and gills with a variable number of appendages. This class includes crabs, shrimps, lobsters, crayfish, and barnacles. Crustaceans have two pairs of antennae
Chordata four main features
Notochord, Dorsal hollow nerve cord, Pharyngeal gill slits, Muscular tail
notocord
a dorsal, flexible rod
that functions as support. It is replaced by bone during development in most vertebrates.
Dorsal hollow nerve cord
forms the basis of the nervous system. In some chordates, the nerve cord becomes the brain and the spinal cord
Pharyngeal gill slits
provide channels across the pharynx to the outside body. The slits become gills for oxygen or for filter-feeding.
