Flashcards in Classification of Stuff Deck (102):
How many species are there?
1.8 million given scientific names
10-100 million estimated
How did Aristotle classify organisms?
Into two kingdoms: Plants and Animals
Who was Carolus Linnaeus (1735)?
Modified Aristotle's system by expanding it to include subgroups called a genus.
A genus could be divided into more specific groups based on their characteristics called species. Species that are similar were placed in the same genus.
-Resposile for binomial nomenclature
What is binominal nomenclature?https://www.brainscape.com/marketing/faq.html
-First word is the Latin name for its genus and is always capitalized
-second word is the latin name for the species and starts with a lower case letter
Who was Charles Darwin?
-19th century naturalist
-provided convincing evidence that evolution of life forms has occurred
-proposed natural selection as the mechanism responsible
-classified organisms based on genetic similarity
Reasons for classifying species:
-Accurate and uniform names prevents:
-uses the same language for all names (latin)
-shows evolutionary relationships
What is phylogenetics?
The study of how organisms are related to one another
-Using the fossil record with characteristics such as morphology, behaviour, and molecular analysis of protein and DNA scientists guess how closely species are related and how long ago they had a common ancestor
What is a cladogram?
A tree like diagram used to classify organisms into hierarchical groups. Represents a hypothetical evolutionary process. Show how organisms are related based on shared characteristics
What is a species?
All the individual organisms of a natural population which are able to interbreed generally sharing similar appearance, characteristics and genetics due to having recent common ancestors
What are the levels of classification in biology?
Domain, kingdom, phylum, class, order, family, genus, species
What are the 3 domains?
Bacteria, archaea, eukarya
What are the major cell types?
Prokaryotes: No nucleus, no defined organelles. Include bacteria and archaea
Eukaryotes: Have a nucleus, membrane bound organelles
How are things classified at the kingdom level?
Cellular organization and methods of nutrition
What are the six kingdoms?
Archaea: Bacteria that thrive in extreme enviroments
Bacteria: Are made only of one cell or a few cells
Protista: Single celled organisms that are neither plants nor animals
Fungi: Absorb nutrients through their skin
Plantae: Use photosynthesis to make food
Animalia: Can move around to obtain food
What is taxonomy?
The science of organizing living things into groups which reflect their natural phylogenetic relationships. Groups are called taxa (singular: Taxon)
What are the earliest fossil records?
3.5 billion years ago, bacteria microfossils
How many species of plants and animals?
15 million animals dependant of 300 000 plants
How does plant extinction affect other organism?
Each plant species supports 50 different animals. When a single plant species becomes extinct many others are threatened. For every plant that becomes extinct it is thought that 20 insects could not survive
What are the three levels of biodiversity?
Genetic diversity, allows to survive environmental change
Species diversity, allows ecosystems to survive environmental change
Ecosystem diversity, allows a diverse range of species to survive
What is species diversity?
The variety of species in a given area
What is selective breeding?
Crossing desired traits from plants or animals to produce offspring that have the favoured traits
What is monoculture and the problems?
The cultivation or growth of a single species. The lack of species diversity and genetic diversity makes species vulnerable to disease, parasites, and predators
What are the benefits of maintaining native populations?
They are uniquely adapted to their environment and do not require special fertilizers, etc.They provide habitat and a food source. Native animals keep population numbers in balance.
What are exotic/invasive species?
Exotic: Not native
Invasive: Have no natural predators
What are keystone species?
Have an extremely large effect on a particular ecosystem. Ex. honey bee, frogs
What is happening to diversity?
By 2025 the earth could 1/5 of all species
What are the main characteristics of kingdoms? (Chart)
Bacteria: King: bacteria, cell type: prokaryote, cell numb: unicellular, cell wall: peptidoglycan, nutrition: autotrophs and heterotrophs, reproduction: asexual
Archaea: King: Archaea, cell type: prokaryote, cell num: uni, cell wall: not peptidoglycan or none, nutrition: autotrophs or heterotrophs, reproduction: asexual
Eukarya: Protista, multicellular and uni, cellulose or none, autotrophs and heterotrophs, asexual and sexual
Eukarya: Plantae, multi, cellulose, autotrophs, sexual
Eukarya: Fungi, multi, chitin, heterotrophs, sexual
Animalia: multi, no cell wall, heterotrophs, sexual
What are viruses?
Non classified as a cell. From 20-400nm. Must infect a host cell in order to be functional
What are the virus shapes?
Helical, enveloped (round), polyhedral, complex/phage
Parts of complex viral particle
1. DNA or RNA
2. A protein coat called a capsid
3. Enclosed by an envelope
4. Some have spikes
What is an incubation period?
The time it takes between when the virus infects a cell and when symptoms appear
What is the lytic cycle
-virus invades host cell and injects its DNA or RNA
-the host cell replicates the parts of the virus and other material in viral DNA
-new viral particles are assembled in the host cell
-the new viral particles are releases to invade new cells
What is the lysogenic cycle
-virus invades and injects DNA
-viral DNA is merged with the host DNA, becoming a provirus
-viral DNA remains dormant for a period of time. May be passed on to daughter cells if the infected cell divides.
-viral DNA is activated, extracted from the host, by a trigger
-the host cell replicates parts of the virus and the viral DNA
-new viral particles are assembled in the host cell
-the host cell is lysed and viral particles are released
What are retroviruses?
A type of lysogenic virus. \
-possess an RNA genome
-rely on reverse transcriptase to reverse transcript the genome from RNA into DNA
-integrated with host DNA with integrase enzyme
What are bacteriophages?
Viruses that infect bacteria
How are viral infections prevented?
-inactive particles of the virus or synthetic proteins
-your immune system makes antibodies that fight the virus
What makes bacteria gram positive or gram negative?
Contain a polymer called peptidoglycan in their cell wall. Amount affects its ability to be stained.
1. Stain with crystal violet
2. Fix with iodine
3. Rinse with ethanol
4. Counterstain with safranin
Gram positive have lots, will retain violet stain
Gram negative have little and will take up pink stain
What are archaea?
-represent the earliest forms of life
-developed when earth was hot and free of oxygen
Groups include methanogens, thermoacidophiles, and halophiles
What are methanogens, thermoacidophiles, and halophiles?
M: -live in anaerobic environments, get energy from CO2, N2, H2S, produce methane
T: live in high temperatures and acidic environment
H: Live in extremely salty environments
What are the shapes of bacteria?
Bacilli: Rod shapes
How do bacteria reproduce?
Binary fission: Under good conditions. Asexual, exponential. (within 20 min)
Conjugation: Less favourable. Exchange of bacterial DNA plasmids between two. Sexual
What is an endospore?
Under extreme conditions some bacilli bacteria form dormant cells called endospores. Form a thickened wall protecting cell from heat and harm. When favourable it breaks down and returns to active bacterium
Bacteria, health, and antibiotics
-if some bacteria are immune or become immune the entire population can reproduce and the antibiotic is useless
-not all bacteria are bad. They play a vital role in the carbon and nitrogen cycles. Some are harmful though.
What are protists?
Don't fit into any other kingdom.
Protozoa: Animal like
Algae: Plant like
Slime/water moulds: Fungus like
What are the four types of protozoa?
Cercozoans: Use pseudopodia
Flagellates: Use flagella
Sporozoans: Are not able to move
What are protozoa?
-single cell and other structures
-many shapes and sizes
-can be parasitic, need to live in moist environments
-similarity of human and protozoa cells make infections hard to treat. Include amoebic dysentery and malaria
What are the types of algae and how are they classified?
Type of chloroplasts and the pigments they contain.
Dinoflagellates: Resposible for red tides
Diatoms : Cell wall of silica. Two parts.
Euglenoids: Heterotrophs and autotrophs
What are the types of slime and water moulds?
Water moulds: Feed on dead or living organisms by extending fungus like threads and releasing digestive enzymes
Plasmodial slime moulds: cells aggregate to form a plasmodium that feeds as a unit by engulfing smaller particles
Cellular slime moulds: Cells feed, divide, and grow individually. Aggregate to form pseudoplasmodium when food is scarce
What are cyanobacteria and their relationship to modern plants?
-responsible for the increase of oxygen 2000 million years ago
-first plants evolved by endosymbiosis, where the endosymbiont lives inside the host (prokaryotic cell)
-same chlorophyll as modern algae and land plants
What are plants?
-photosynthetic autotrophs containing chloroplasts
-cell walls made of cellulose
-respond to environment and grow through use of hormones
How are plants classified and what are the main lineages?
Presence of vascular system (xylem, water and phloem, sugars and nutrients)
Flowers (enclosed seeds)
1. Nonvascular: no vascular or seeds
2. Seedless vascular
3. Gymnosperms: unenclosed seeds
4. Angiosperms: Enclosed seeds
What are the two main types of plants?
Vascular (Tracheophytes) and Bryophytes
What are bryophytes?
-found in moist, shady areas
-small size bc no vascular
-no true roots, stems, or leaves
-need water for reproduction
-reproduce using spores
What are spores?
a single waterproof cell that can grow into a new (haploid)organism
What is the bryophyte life cycle?
A. Gametophyte produces sporophytes that grow on stalks
B. Spores are released from the capsule of the sporophyte and develop into a male or female gametophyte
C. Female gametophyte develops an archegonium, the structure that produces the eggs
D. Male gametophyte develops an antheridium, the structure that produces the sperm
E. Gametes releases, fertilization occurs
F. A zygote is produce that will develop into a sporophyte
What are traceophytes?
Contain two types of specialized vascular tissues
Presence of vascular system allows them to grow tall
Has specialized organs: Roots, stems, leaves
What are the two types of traceophytes?
Seedless and Seeded
What is an example of a seedless vascular plant?
-Contain a vascular system
-Grow in moist, shady areas
-Has underground stems, roots, and large leaves called fronds
-reproduce using spores
What are the advantages of seed bearing plants and how is this process different?
Reproductive strategy does not need water
Seed contains a fully developed embryo, a food supply, a water-proof seed coat
Sperm transferred in water proof pollen through pollination
Developed seed bearing structures: Cones and flowers
What are the two types of seed bearing Tracheophytes?
What are gymnosperms and how do conifers reproduce?
-most common are conifers
-have leaves called needed or scales with reduced surface area and thick waxy coat to prevent water loss and freezing
1. Male cones produce pollen and the female cones produce eggs and seeds
2. Pollen is inefficiently transferred by the wind
3. Once mature the plant depends on the female cone to dry out and open scattering seeds by the wind
What are angiosperms?
1. These are flowering plants that encourage direct and efficient pollen transfer
2. Pollinators are flying insects, birds, bats, that transfer pollen from flower to flower
3. Flowers contain ovaries which is where egss/seeds are produced
4. A fruit is the pollinated ovary containing mature seeds
How does fruit aid in the dispersal of seeds?
1. Winged fruit glides to a new location
2. Floating fruit floats to a new location
3. Fleshy fruit have seeds that survive in the digestive system of animals
4. Spiny fruit have velcro like projections that attach to the fur of animals
What are fungi cells like?
Most are multicellular, except yeast
Cells walls are made of carbohydrate called chitin
Chitin is a very hard substance and is resistant to water loss
Digestion of fungi
Digest their food externally and absorb the nutrients
Most are decomposers
They feed by absorbing small organic molecules. They secrete digestive enzymes and break down food into small molecules outside. The nutrients are usually transported in a vascular system
Biological role of fungi
-some are parasites
-many are symbiotic with plants
-some are saprobic (live on dead matter) and recycle materials into the ecosystem
-cause diseases like athletes foot
-cause yeast infections
What is lichen?
A symbiotic relationship between a fungus and a photosynthetic organism
-fungus in lichen is usually an ascomycetes
-photosynthetic organism is either a green algae or cyanobacteria
What are common characteristics of fungi?
-Body is made of long filaments of hypae which form a mycellium
-fungi reproduce sexually and asexually
-shape and size varies
-Generally non motile but some spread by spores
Anatomy of fungi
A network of filaments called hyphae
A network of bundles of hypae called mycelium. In many fungi these are subdivided into sections called septa
Asexual reproduction of fungi
-yeast cells reproduce by budding
-budding is a process in which part of the cell pinches itself off to produce offspring
-most fungi can grow from a small piece of mycellium that breaks off, fragmentation
-most fungi can reproduce asexually by spores
Sexual reproduction of fungi
-to provide an adaptive advantage, during environmental stress
What are zygomycota moulds?
-multicellular with microscopic filaments of hyphae and mycellium
-reproduce by fragmentation and releasing spores
-on bread and stuff
What is the zygotic life cycle?
A. The above ground structure of a mushroom usually consists of a stipe and supports a cap
B. In the gills' basidium haploid nuclei fuse to produce a zygote
C. The zygote undergoes meiosis to produce haploid basidospores
D. When a basidospore lands in a suitable enviroment it germinates and produces hyphae that grow down into the soil to form haploid mycellium
E. When mycelia from two different mating types come together the hyphae fuse. A new mycellium forms. Each cell contains two haploid nuclei
F. Buttons, (compact hypae) form under the surface
What is the fern life cycle?
A. A sporangium produces haploid spores that germinate to form a gametrophyte called a prothallus
B. The prothallus produces antheridia and archegonia
C. Sperm from the antherida swim via a droplet of water to an egg produced by the archegonium
D. The fertilized egg begins to grow into a sporophyte
E. The sporophyte matures, and roots and fronds develop out of the growing rhizome
F. Sori develop on the pinnae. Spores are formed by meiosis
What is the difference between a dicot and monocot?
Mono: Simpler, one cotyledon, veins usually parallel, scattered vascular bundles
Di: Two cotyledons, net like veins, ringed vascular bundles
What are characteristics of animals?
-multicellular, arranged into tissues (except sponges)
-35 phyla but 9 contain the bult
Methods of reproduction in animals?
How we classify members of the animal kingdom
-type of coelom (body cavity)
-presence of segmentation
-presence of hair
-presence of feathers
What are the three layers in animals?
(All except sponges and cnidarians)
What are the types of symmetry in animals?
What is a coelom?
A fluid filled body cavity that contains a digestive tract
There are coelomates and acoelomates
What are the two main groups of animals?
Vertebrates: Contain backbone and spinal cord. Most chordata
What are porifera?
-have pores over their surface that allow water to enter and leave the sponge. On surface called oscula
1. Feed by filtration
2. Have no internal organs
3. Have an internal skeleton made of a microscopic mesh
4. Have a unique type of cell called the choanocyte
What are cnidaria?
-radially symmetrical animals
-one end of body has mouth and tentacles
What are platyhelminthes?
-Planaria are freshwater
-Flukes are in/external parasites
-bilateral symmetry and cephalization (head development)
What are mollusca?
-snails and stuff
-have a fleshy mantle that secretes and modifies the shell
-produce and external skeleton (exoskeleton) of calcium carbonate
-normal digestive and reproductive system
What are the different ways we classify species?
Morphology, biologically (whether they naturally reproduce), phylogenetic
What is some of the evidence of relationships between species?
Similar anatomy and morphology, physiological evidence (biochemistry), DNA evidece
Draw generally the gametic, zygotic, and sporic life cycles
Gametic: Diploid organism --> Meiosis --> Haploid gametes --> fertilization --> diploid zygote --> mitosis --> diploid organism
Diploid zygote --> meiosis --> haploid spores --> mitosis --> haploid organism --> mitosis --> fertilization of gametes --> diploid zygote
Diploid organism --> meiosis --> spores --> Mitosis --> Haploid organism --> mitosis --> Fertilization --> zygote --> Diploid organism
What is the evolution of plants?
700 mya: Ancestral green algae
-->400-500 mya: Non vascular plants (mosses, etc)
-->350 mya: First vascular plants
-->Seedless plants (ferns)
-->First seed plants
-->Angiosperms (140 mya)
What are the two body forms of cnidarians?
Polyp: tube shaped sessile body form
Medusa: The umbrella shaped, free swimming form
What are nematodes?
-roundworms that have unsegmented bodies and lack appendages
-may be free living, predaceous, or parasitic
-have simple structure of internal body cavity called pseudocoelom
-are the most numerous multicellular organisms on earth
What are annelida?
-phylum of animals (earthworms and leeches) comprising segmented worms with a coelem
-body is segmented and bilateral symmetry
-coelom well developed and divided by septa (except leeches)
-blood system closed and segmented
-Complete digestive system
-respiratory gas exchange through skin or gills
-excretory system typically has pairs of nephrida (kindeys) in each segment
-nervous and sensory systems
-hermaphroditic or separate sexes
-can reproduce by budding
-mostly in wet terrestrial and aquatic environements
What are arthropods and some types?
-invertebrates with exoskeletons made of chitin, segmented bodies, and jointed limbs
A. Crustacean: 5-7 pairs of legs
-first pair often pinchers
-body covered in shell
B. Myriapoda: Centipedes: Long thin bodies, 2 pairs of legs on many segments
C. Arachnids: 4 pairs of legs, 2 segments
D: Insects: 3 pairs of legs, 3 segments. Most diverse
What are chordata?
-internal bony skeleton
What are reptiles?
-class of chordata
-cold blooded, have scales, lay eggs
-can't regulate body temperature (do not expend the energy)
-breathe through lungs, some can absorb through mouth
-lay eggs on land
What are fish?
-class of chordata
-live in aquatic environments
-usually have paired fins and scales
-most lay large numbers of eggs
What are amphibians?
-class of chordata
-eggs are naked, lack amnion
-lack any skin coverings
-go through larva and adult stages
-have moist skin to breathe, may have lungs
What are birds?
-class of chordata
-most can fly
-beak rather than teeth
-nearly hollow bones
What are mammals?
-class of chordata
-warm blooded, posses hair, and suckle their young
-Homeothermic: Produce own body heat
-Internal fertilization and internal incubation (generally)