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What is biology?
Biology is the study of life.
Name six characteristics of living things.
- Made up of cells
- Obtain and use energy
- Grow and develop
- Respond to their environment
- Adapt to their environment
What is biodiversity?
The variety of life in the world.
Approximately how many different species are there in the world?
Between 5 million and 50 million
What is taxonomy?
The science of naming, identifying and classifying species. It allows organisms to be identified and represents relationships among them.
What is binomial nomenclature?
The two-naming system of Carolus Linnaeus which names an organism by their genus and species.
What is morphology?
The study of form and structure of organisms.
Explain how to name an organism.
Genus species (either itallic/handwritten/underline each individual word)
What is a species?
A species consists of members of a group that share a gene pool therefore they can interbreed and produce fertile offspring.
In interbreeding, why does it matter which is the male or female?
Genders give different DNA. For example a male donkey and femal horse create a mule, while a female donkey and male horse create a hinney.
What are the six main levels or taxa of classification from broadest to most specific.
Kingdom, Phylum, Class, Order, Family, Genus, Species
Name the six kingdoms.
Bacteria, Archaea, Protista, Fungi, Plantae, Animalia
What is genetic diversity.
The sum of all present, different genes in a particular species. Genes differ slightly between organisms of the same species, determining hereditary differences and allowing species to adapt and ensure survival of the species.
What is species diversity?
The variety of species and relative abundance of the species in a given area. A variety of species allows ecosystems to survive environmental changes.
What is ecosystem diversity?
The diverse range of habitats and the various organisms that live in the habitats and the relationships that connect them.
What is a keystone species?
A species that have a disproportionately large effect on the ecosystem in which they live.
What is selective breeding of an organism to ensure specific traits an example of?
Manipulating genetic diversity
What is a dichotomous key?
A series of questions or statements regarding the features of an organism where each question will lead to another until the eventual labeling of the organism.
What is the classification system based on phylogeny called?
What is phylogeny?
The evolutionary development of a group of organisms based on a shared common ancestor.
Explain a phylogenetic tree.
Used to illustrate the relationship among various species, it shows the evolutionary development of a group of organisms with a shared common ancestor, grouped together into taxa. The root of the tree represents the oldest ancestral species, where upper ends of branches are the present day descendants. Where the branches fork, called nodes, are points in the past at which an ancestral species splits into two new species.
What is a node?
The point in a phylogenetic tree where an ancestral species splits into two new species.
What is a taxa?
A taxonomic group of any rank, such as a species, family, or class.
Name four ways that taxonomists can determine the relatedness of organisms.
- Evidence from anatomy (fossilized evidence, structure of anatomy)
- Evidence from development (comparing stages of embryonic development)
- Evidence from biochemistry (comparison of biological molecules - fats/proteins/carbs/nucleic acids etc.)
- Evidence from DNA (comparison of DNA sequence and genes)
Describe the three domain classification system
- Bacteria (microscopic, unicellular, prokaryotic)
- Archaea (microsopic, unicellular, prokaryotic)
- Eukarya (complex, eukaryotic, membrane-bound organelles)
How does the classification of organisms benefit us?
It leads to a better understanding of biodiversity by allowing us to see similarities and differences between organisms, and measures the overall diversity of organisms ina particular region.
What is the kingdom achaea?
Meaning "early" or "primitive", these organisms thrive under extreme conditions because of unusual fats in cell membranes, and are autotrophic.
Name the three main groups of archaea.
Methanogens, halophiles, thermoacidophiles
What is a methanogen?
Of the kingdom archaea, they are methan producing, live in anaerobic environments, use CO2, N2 or H2S as a source of energy.
What is a halophile?
Of the kingdom archaea, they are salt loving and live in extremely saline environments, and are so well adapted they cannot live in weaker salt solutions.
What is a thermoacidophile?
Of the kingdom archaea, they are heat and acid-loving organisms that grow best in extremely hot and acidic envrionments of temperatures over 80 degrees celcius and use energy from sources around them.
What are the four letter used to determine DNA chemicals.
What is the name of the genetic progenitor of all bacteria, plants and animals?
Give characteristic of bacteria.
- Some stick together in colonies
- Smallest living cells
- Single chromosome in the form of a DNA loop
- Reproduce asexually via binary fission
- Thrive only in moist environments
Name five ways of classifying bacteria.
- By Gram Stain (Cell wall composition)
- By shape
- By configuration
- By respiration
- By type of nutrition
Explain a gram stain.
Used to classify bacteria by cell wall composition. If it is gram positive that means the bacteria have a THICK wall and stain PURPLE. If it is gram negative this means the bacteria have a THIN wall and outer membrane, preventing the cell wall from absorbing the gram stain. They appear PINK/RED.
Explain how bacteria is classified by shape.
- Cocci - round (singular = coccus)
- Bacilli - rod shaped (singular = bacillus)
- Spirilli - spiral shaped (singular = spirillum)
Explain how bacteria can be classified by configuration.
- single (mono)
- double (diplo)
- chain (strepto)
- clump (staphylo)
What would you call a chain of cocci bacteria if classifying by configuration?
What is aerobic?
Organisms that require oxygen
What is anaerobic?
Organisms that do not require oxygen.
What is a obligate anaerobe?
Die when exposed to oxygen
What is a facultative anaerobe?
can grow with or without oxygen
Explain how bacteria can be classified by how they acquire energy.
- Photoautotroph - Use light from the sun through photosynthesis
- Photoheterotroph - Use photosynthesis and consume other bacteria
- Heterotroph - consume other bacteria/organisms
- Chemoheterotrophs - recieve energy from chemical reactions
Explain how bacteria move.
- Environmental factors
- Flagella (whip like tails)
- Cilia (beating in unison)
- Corkscrew motion for some spiral-shaped bacteria
- Secrete mucous to slide around
Explain two ways in which bacteria can reproduce.
Asexual or genetic mixing
How do bacteria reproduce asexually?
Through binary fission. This takes roughly twenty minutes, where the DNA replicates, cytokinesis occurs and then the result is two identical daughter cells.
Explain genetic mixing or recombination.
- A sexual reproduciton for bacteria in one of three ways:
- Transformation: bacteria pick up pieces of DNA from environment and incorporate it into there own genetic material
- Conjugation: occurs in less favourable conditions, bacterial cells link through a 'sex pilus' and transfer all or part of its chromosomes to another bacteria
- Transduction: viruses infect bacteria, carry genes from one cell and inject them into another
Explain a bacterial dormant stage.
When resources are too limited to survive, a thick internal wall surrands DNA and small amount of cytoplasm, creates an endospore which is resistant to lack of water and nutrients.
What is the main function of bacteria of decay?
To help in decomposition of dead animals, plants and return their minerals to the earth.
What are the two main uses of bacteria of fermentation?
Breakdown of food in human intestines and change grape juices into wine.
What is the function of nitrogen-fixing bacteria?
Change nitrogen in air into nitrates to enrich the soil.
What is the symbiotic relationship between nitrogen-fixing bacter and roots of plants?
Bacteria create nitrates, plant provides food.
Why are there cheeses of different flavours?
There are many different types of cheese bacteria.
What is the function of sour milk bacteria?
Causes milk to clot and sour, creating popular food such as yogurt.
What is diptheria bacteria?
Causes damage to the human body through poison given off as waste. We get a vaccine from this.
What is the typhoid fever bacteria?
Bacteria that is harmful, recieved from drinking unsanitary water.
Why is the capsule imporant to pneumonia bacteria?
Protects from organisms antibodies.
What are the three distinct groups within the protist kingdom?
- Animal-like protists (Protoza) - engulf food source
- Plant-like protists (some called Algae) - photosynthesis
- Fungi-like protists (Slimemoulds or watermoulds)
Describe characteristics of the kingdom protista.
- Most unicellular/some colonial/some multicellualr
- Most are aerobic
- Reproduce asexually through mitosis
- Thrive in moist environments
Why do protists need moist environments?
To not dry out and mobility
Describe characteristics of protozoans.
- No cell walls (move fluidly)
- Most are motile
- Live in moist environments
- Some cause disease
How are protozoans heterotrophs?
Either engulf food via phagocytosis or absorb nutrients via diffusion.
What is phagocytosis?
A way or protozoans to engulf their food.
Name the four main groups of protozoa.
- Sarcodines (Sarcodina) - use pseudopods (limb-like extensions of cytoplasm) for movement eg. Amoeba
- Flagellates (Zoomastiginia) - move using flagella
- Sporozoans - mostly parasites infecting hosts, form spores at some point in their life cycle
- Ciliates - move using cilia, usually large
Why are some protists called 'plant-like'?
They contain chlorophyll and can perform photosynthesis.
Name the six types of plant-like protists.
Dinoflagellaes, Diatoms, Red algae, Brown algae, Green algae, Eugleoids
- Plant-like protists
- two flagellae
- reproduce quickly to form a toxic "red tide"
- Plant-like protists
- most abundant in oceans
- biggest component of plankton
- rigid cell wall made of silica
Describe Red Algae.
- multicellular (also called seaweed)
- found mainly in warmer seawater
- branched with feathery fronds
- pigments absorb longer wave lengths (red), survive deeper depths
Describe Brown Algae.
- multicellular (also called seaweed)
- larger than red algae
- large, flat fronds - withstand pounding of tides
- mucilage-like material in cell wall to retain water
- kelp is member of family
Describe Green Algae.
- most plant like (same type of chlorophyl as land plants)
- cell walls have cellulose
- store food as starch
- found in fresh water and damp places
- fresh water
- have two flagellae, one much longer than the other
- about half have chlroplasts, other half are heterotrophs
- Eye spot used to detect light
- contractile vacuole used to collect and express escess water
Why are fungi-like protists difficult to classify?
Contain characteristics of of protozoa, plants and fungi. (Like prtozoa, they are motile and ingest food. Like plants they have cellulose cell walls. Like fungi they produce spores.)
Name the three types of fungi-like protists.
- Cellular Slime Moulds - exists as indivual 'ameobid' cells with one nucleus each, ingest bacteria or yeast, come together to form a 'pseudoplasmodium'
- Pasmodial Slime Moulds - visible to naked eye as tiny slug-like organisms, blob is plasmodium, engulfs food like an aboeba
- Water Moulds - 'filamentous', live on dead organic matter, can be parasites
What is a pseudoplasmodium?
A jelly-like mass which produces spores from Cellular Slime Moulds, which are fungi-like protists.
Are all protists prokaryotic or eukaryotic?
What is a virus?
A lifeless particle that carries out no metabolic function nor can it reproduce on its own without first invading a living cell.
Name characteristics of viruses.
- All are infectious/caue disease
- Have no cytoplasm, organelles or cell membranes
- Consist of DNA or RNA surronded by a protective protein called a "capsid"
- Do not carry out respiration nor do they produce/use energy or produce waste
- "Mobile genes" that parasitize cells
- Extremely small
Why are viruses significant?
Responsible for many human diseases. Can control populations in ecosystems.
What is the difference between an epidemic and a pandemic?
- Epidemic = rapidly spreading outbreak of disease in particular area
- Pandemic = epidemic spreads on a global scale
What is the origin of viruses?
Amongst the oldest of particles, developed as small fragments of genetic material that became enclosed.
What are different types of viruses?
- Bacteriphage - viruses that infect bacteria
- Adenovirus - largest nonenveloped virus
How do we classify viruses?
- By shape (polyhedral, spherical, cylindrical)
- By type of disease that they cause
- By the type of organism that they infect
- By the type of nucleic acid they have
Describe they Lytic Cycle.
- Attachment & Entrance
- Protein & Nucleic acid replication
- Assembly (infected cell makes and assembles viruses)
- Release of new virus particles
When do viruses become active?
When their genetic material has been activated and taken control of a living cell.
What is the Lysogenetic cycle?
DNA stay dormant for many years, bacterium continue to grow and divide normally, making new copies of virus until environmental conditions become favourable.