Chapters 1-3.1 Flashcards
What is Biodiversity?
Variety of life in the world. Biodiversity allows ecosystems to change over time in order to adapt to their changing environment, it is used as a gauge of the health of ecosystems.
What is genetic diversity?
Different genes and combinations of genes in a species.
What is species diversity?
The variety (different kinds of species/organisms) and abundance (# of individuals) of species in a given area. Species Interactions
What is ecosystem diversity?
Different habitats, niches, and species interactions.
What is structural diversity?
The range of physical shapes and sizes within a habitat or ecosystem
What is a keystone species?
A species that has a disproportionately large effect on the ecosystem in which they live. The presence or absence of a keystone species can have a dramatic impact on the ecosystem.
What is the importance of classification?
We can distinguish organisms from each other It helps us understand how related living things are to each other
What and how do you make a dichotomous key?
Make one.
What is taxonomy?
Taxonomy is the science of naming, identifying and classifying species. Species are placed into taxonomic levels known as taxa, based on shared characteristics.
What are all the taxonomic levels?
Species, Genus, Family, Order, Class, Phylum, Kingdom, Domain.
What is binomial nomenclature?
The method used to come up with the names of scientific species. Binomial nomenclature has two main characteristics: A two part Latin name A hierarchy of species into broader groups ex: Panthera leo (lion) and Panther pardus (leopard)
What is morphology?
Grouping organisms according to their structures
What is phylogeny
The evolutionary development of a group of organisms. Biologists use phylogenetic analysis to compare living organisms to extinct organisms. This allows us to determine how related extinct organisms are to modern organisms.
What and how do you use a phylogenetic tree?
Diagram that shows evolutionary relationships between organisms
What are clades?
A taxonomic group that includes a single common ancestor and all its descendants. Clades are used in phylogenetic trees to group species together.
What are Prokaryotes?
Single-celled organisms with no membrane bound organelles.
What are Eukaryotes?
Single-celled or multicellular organisms whose cells contain membrane bound organelles.
What are the three domains?
-Eubacteria -Archaea -Eukarya
Describe Eubacteria and Archaea (domains).
These organisms are known as prokaryotes. They are: -Microscopic -Unicellular -Have DNA but no nucleus -Lack membrane bound organelles
Describe Eukarya (domain)
All other organisms are a part of the eukarya domain. These organisms are made up of eukaryotic cells and: -Contain a nucleus -Contain membrane bound organelles -Can be microscopic or large -Can be single-celled or multicellular
What are the kingdoms of Eukarya?
-Protists -Fungi -Plantae -Animalia
What two domains do prokaryotes belong to?
-Bacteria -Archaea
What are some of the roles of bacteria?
Bacteria decompose organic matter and release nutrients back into the ecosystem Bacteria convert nitrogen gas into nitrogen compounds which plants can absorb from the soil. This nitrogen is passed on to animals when they eat the plants.
Name 6 of the common types of bacteria?
-Proteobacteria (purple bacteria) -Green bacteria -Cyanobacteria (blue-green algae) -Gram-positive bacteria -Spirochetes -Chlamydias
Describe proteobacteria (purple bacteria).
-Use a version of photosynthesis to obtain energy -Ancient forms were the ancestors of mitochondria in eukaryotes -Responsible for diseases including bubonic plague, gonorrhea, dysentery, ulcers.
Describe green bacteria.
-Use a version of photosynthesis to obtain energy -Found in salt water environments and hot springs
Describe cyanobacteria (blue-green algae).
-Use same photosynthesis as plants to obtain energy -Ancient forms were ancestors to eukaryotic chloroplasts -Play major roles as producers and nitrogen fixers in aquatic eco-systems.
Describe gram-positive bacteria.
-Cause many diseases including strep throat, pneumonia, meningitis -Used in food production (ie. Lactobacillus in yogurt)
Describe spirochetes.
-Spiral shaped flagellum to move in corkscrew motion -Cause syphilis -Symbiotic relationship – live in termites intestines and digest wood fibre for termites.
Describe chlamydia.
-Parasites that live within other cells -Cause chlamydia -Cause trachoma, which causes blindness in humans
What are the three basic shapes of bacteria?
-Spherical -Rod-shaped -Spiral-shaped
Describe spherical bacteria.
-Also known as cocci -Examples of cocci include bacteria that cause pneumonia
Describe rod shaped bacteria.
-Also known as bacilli -Examples of bacilli include E. coli bacteria which are found in your intestine and in your feces
Describe spiral shaped bacteria.
-Also known as spirochetes -Examples of spirochetes include bacteria that cause lyme disease and bacteria that cause syphilis
Describe the cell wall of bacteria.
-Nearly all bacteria are protected by a cell wall -Cell walls in bacteria display structural diversity, meaning they are different from the cell walls of plant cells and archaea
What are the two types of cell walls in bacteria?
- Made of a thick coat of sugars 2. Less thick coat of sugars with an additional outer membrane
Describe the different ways bacteria are able to move.
-Some bacteria have a tail called a flagella -The flagella is used as a whip or propeller to allow the bacteria to move -Other bacteria glide on a slimy mucous that they secrete -Bacteria also have little hairs called pili, which Help them attach to other cells/structures.
Describe where and what contains bacteria DNA?
-Bacteria DNA is located in a single chromosome, plus multiple plasmids. -There is no nucleus. Plasmids are small loops of DNA that carry a small number of genes.
What are the ways bacteria obtain nutrients?
-Heterotroph -Chemoheterotroph -Photoautotroph -Photoheterotroph
Describe heterotroph?
-Consumes organic molecules by eating other organisms -Lives in a variety of environments -Examples include: E. coli
Describe chemoheterotroph?
-Consumes energy released through chemical reactions involving ammonia and hydrogen sulfide -Lives in dark and chemically harsh environments (ie. boiling hot springs, digestive systems) -Examples include: Methanococcus jannaschii
Describe Photoautotroph.
-Uses sunlight to turn carbon dioxide into sugar (similar to photosynthesis) -Lives in place with lots of light -Examples include: Cyanobacteria
Describe Photoheterotroph.
-Can obtain energy by consuming organisms or producing it themselves -Lives in places with lots of light -Examples include: Helicobacter pylori
What is one way bacteria reproduce asexually?
-Bacteria reproduce through a process known as binary fission. -Binary fission is an example of asexual reproduction (a mate is not needed) -Binary fission creates identical copies of the original bacteria
Explain the process of binary fission?
- Parent cell DNA duplicates 2. Cell begins to divide 3. Daughter cells separate
If binary fission creates identical bacteria, how do bacteria achieve genetic variation in order to adapt to their environment?
- Transformation 2. Conjugation 3. Transduction
Describe the process of transformation.
-In transformation, some bacteria take up DNA from the environment and incorporate it into their own DNA. -In some cases, this DNA comes from dead bacteria
Describe the process of conjugation.
-Conjugation is the process by which two bacteria cells temporarily join and exchange genetic material -The DNA that gets exchanged is from a plasmid -A plasmid is a separate ring of DNA that are not a part of the cell’s chromosomes
Describe transduction/horizontal gene transfer.
Transduction is the process by which viruses which infect bacteria carry genes from one bacterial cell and inject them into another bacterial cell
Describe endospores.
-When resources are too limited for bacteria to survive, they enter a dormant stage called an endospore. -In this stage, a thick internal wall forms around the DNA and the outer cell disintegrates. -Endospores can live for years with no nourishment and in very harsh environments.
Describe antibiotics.
-Antibiotics are used to kill bacteria. -Antibiotics attack the wall that surrounds the bacteria to stop reproduction
Describe archaea.
-Archaea are more complex than bacteria -Can survive in some of the most hostile places on the planet (ie. methane-saturated swamps, mud devoid of oxygen, edges of active volcanoes) -Archaea reproduce asexually by binary or multiple fission, fragmentation, or budding
What are the different energy sources different archaea use?
-Phototrophs utilize sunlight -Lithotrophs utilize inorganic compounds -Organotrophs utilize organic compounds Archaea can reproduce via binary fission or budding.
What are viruses and describe them?
-Viruses consist of genetic material surrounded by a protein capsule. A virus particle is known as a capsid. -The genetic material is stored in a piece of DNA or RNA -They can adapt to the environment via mutations to their DNA -They are not living organisms
What are viruses not/ what cant hey not do?
-Made of cells -Reproduce asexually -Live without a host cell to infect
What is the general structure of a virus?
-A virus is composed of a short piece of nucleic acid (DNA or RNA), surrounded by a protein capsule -Some viruses also have an outer membrane -This membrane helps the virus merge with a host cell that it will infect
What are virus protein coats?
-The protein coat on a virus cell is like a key for a specific lock. -Patterns on the coat are very specific and can only attach to specific host cells (HIV virus can only infect T cells of the immune system) -Viruses called bacteriophages can only attach to and infect bacterial cells
Describe when and how viruses reproduce?
-When a virus infiltrates a cell, it unloads its genetic material, takes control of the cell, and replicates. -Replication may occur immediately, or the virus may lie dormant before eventually replicating -Viruses reproduce in 2 basic ways: the lytic cycle and lysogenic cycle
Describe the lytic cycle.
1.The virus attaches itself to a host cell 2.The virus injects its DNA into the host cell 3.The host cell unknowingly makes copies of the viral DNA, thus creating replicas of the original virus 4.Once 20 - 500 copies of the virus are made, they burst out of the host cell, in turn, rupturing the host cell. This rupturing is known as lysis.
Describe the lysogenic cycle
1.The virus attaches itself to a host cell 2.The virus injects its DNA into the host cell 3.Viral DNA inserts itself into the cell’s DNA 4.Cells reproduce normally, replicating viral DNA at each cell division. There are no symptoms of infection at this point. 5.Occasionally, the viral DNA will separate itself from host cell DNA and will enter the lytic cycle
What are vaccines?
Vaccines introduce a “dead version” of the virus to you. Your body creates antibodies which automatically attack and kill the virus when it encounters it.
What are viroids?
Small infectious pieces of RNA that can cause disease in plants. It is currently unknown how viroids cause disease.
What are prions?
Oddly shaped infectious proteins that cause brain disease. Prions enter an animal’s tissue and when another animal eats that tissue, brain disease may occur.
What are protists?
A wide range of eukaryotic organisms that do not belong in any of the other kingdoms. All eukaryotes that are not plants, animals or fungi are classified as protists.
List the characteristics of protists.
-Mostly single-celled organisms (some multi-celled organisms such as kelp) -Live in diverse environments, both aquatic and non-aquatic -Usually phototropic producers in aquatic systems (use light to produce energy) -Some protists are parasitic (need a host to survive)
Describe Protists structure and function.
Look at a diagram to check knowledge.
What is infolding?
The folding of the prokaryotic cell membrane that resulted in the modern ER and nucleus
Describe the origin of eukaryotic cells.
The nucleus and endoplasmic reticulum of eukaryotic cells arose from an infoding of the prokaryotic cell membrane.
What is endosymbiosis?
A relationship that consists of a single celled organism living inside of another organism.
Name some ways which protists move.
-Pseudopodia -Flagella -Cilia Some protists are immobile and rely on water currents, wind, or passing animals to be transported from one location to another. Many of these protists can release spores which enter other organisms and live as a parasite.
Describe pseudopodia.
Amoebas move by streaming cytoplasm into cellular extensions known as pseudopodia in the direction they want to move (fake feet).
Describe flagella.
Tail-like extensions which act as a propeller for the cell.
Describe cilia.
Tiny hair-like extensions that cover the cell membrane
List the ways which protists can reproduce.
-Divide by binary fission (similar to bacteria) -Creates identical organisms that lack genetic diversity -Form of asexual reproduction -Genetic diversity can be obtained via conjugation (similar to bacteria)
Name three types of protists.
-Animal-like protists -Plant-like protists -Fungus-like protists
Describe “animal-like protists”
-Heterotrophs that capture and digest food -Food is engulfed by cell and a vacuole is created around the food to digest it -Examples include: amoeba
Describe plant-like protists.
-Autotrophs that make their own food -Contain chloroplasts that allow them to take in sunlight and carbon dioxide to create food (energy) -Examples include: algae and plankton
Describe fungus-like protists.
-Heterotrophs that feed mostly on decaying organic matter -Examples include: moulds
Describe the connection between climate change and protists.
As carbon dioxide levels increase, carbon dioxide dissolves in water and forms carbonic acid, which lowers pH levels of the water. Plankton, and other protists, cannot handle this change in pH and as a result, are beginning to die off. Since they are at the bottom of many food chains, the whole food chain is at risk of collapsing.
Describe fungi.
-Fungi are a kingdom within the eukarya domain. Hence, they are made of eukaryotic cells (more closely related to animals and humans than to plants) -Break down organic matter to obtain nutrients -Obtain oxygen from the environment (no mitochondria or chloroplasts)
Describe the fungi process of decomposition
-Fungi recycle nitrogen by breaking down organic material (ie. fallen logs, dead animals, etc) -Roughly 80% of animals live in a symbiotic relationship with fungi where they receive essential nutrients from fungi
Describe fungi as parasites.
-They invade a host organism and feed off the organism’s cells or bodily fluids. -This can cause disease and even be fatal for the host organism -Examples include: foot fungus, thrush
Describe structures of fungi.
-Mostly multicellular (except for yeast) -Cell bodies are composed of hyphae, tiny threads of cytoplasm surrounded by plasma membrane with a cell wall around it -For large mushrooms, the part you see above ground is the fruiting body -The majority of the fungi is found underground
Describe hyphae.
-Hyphae within an organism are connected, allowing organelles to flow from one cell to the next -Helps with transferring nutrients between cells -Hyphae branch as they grow, creating an interwoven mat known as a mycelium
Describe mycorrhizae.
-Vast networks of mycelia extend through the soil and form mycorrhizae. -Mycorrhizae form a symbiotic relationship with plant roots -The fungus receives sugars, starches, proteins, and lipids from the plant roots. In return, the fungus acts as an extension of the plant roots to collect water and phosphorus from deep within the soil. -Since mycorrhizae are much thinner than plant roots, they can penetrate hard to reach places
How do fungi reproduce asexually?
-Fungi reproduce asexually when a piece of the hyphae breaks off and releases spores. -Spores are haploid cells (half the # of chromosome) -Similar to sperm and eggs -Spores get dispersed by the wind until they land in an area with favourable growing conditions
How to fungi reproduce sexually?
-Fungi come in two different sexes known as ‘+’ and ‘-’. -Opposite haploid cells grow towards each other and fuse to form a diploid zygospore -Diploid = contains a full set of chromosomes -Utilizing sexual reproduction allows fungi to produce genetically unique offspring
Describe the connection between fungi and climate change.
As temperatures increase, many plants have begun migrating farther north, however the soil ecosystem in these new areas may not be suitable for these plants. As a result, the symbiotic relationship developed between plants and fungi may be jeopardized. Air pollution has already destroyed 50% of mycorrhizae in Europe.
