Biology Exam Review PDF

Biology Exam Review Ian Hobdari Diversity Of Living Things - Lessons 1-4 Genetics - Lessons 1-8 Evolution - Lessons 1-6 Animal Systems - Lessons 1-4 Diversity of Living Things Lesson #1 Key Concepts: -​ Biodiversity is the variety of life...

Biology Exam Review Ian Hobdari Diversity Of Living Things - Lessons 1-4 Genetics - Lessons 1-8 Evolution - Lessons 1-6 Animal Systems - Lessons 1-4 Diversity of Living Things Lesson #1 Key Concepts: -​ Biodiversity is the variety of life on Earth Characteristics of all Living Things: -​ Made of cells -​ Respond to their environment -​ Reproduce -​ Adapt to their surroundings -​ Grow and develop -​ Use and need energy​ - A good way to remember this is by using the term “MR RAGU” Classifying Species: -​ Biological species is a group of organisms -​ For example, the labradoodle is not infertile (meaning they can produce) and so the labrador and poodle are part of the same species -​ A zorse (zebra + horse hybrid) are fertile, but their offspring are not, meaning they are not part of the same species -​ A hybrid is offspring that is successfully produced from two animals -​ Taxonomy: the branch of biology that classifies organisms and assigns each organism a universally accepted name 3 Levels of Biodiversity: Genetic Biodiversity Species Diversity Ecological Diversity It is important because it benefits It is important because organisms The variation in the different a species survivor rely on other species for an ecosystems, it is important to hold increased rate of survival, and different species in their different their survival relies on eachother habitats Threats to Biodiversity: 1)​ Habitat Loss 2)​ Invasive Species 3)​ Population 4)​ Pollution 5)​ Over Exploitation Darwin’s Theory of Evolution 1)​ Organisms produce more offspring than can survive, from the offspring that do survive, many will never reproduce 2)​ Because more organisms are produced than can survive, there is intense competition for resources 3)​ Individuals that are best suited to their environment survive and reproduce, while organisms that are less suited for their environment often die or will not reproduce 4)​ The species that are alive on Earth today are descended with modification 5)​ These all make up the process of “natural” selection that causes many of the species to change over time Early Attempts at Classification (Aristotle): Organisms were first classified over 2000 years ago by the greek philosopher, Aristotle 1)​ Aristotle first sorted organisms into two groups: Plants and Animals 2)​ He divided the animals into three groups:​ a) Land Dweller​ b) Air Dweller​ c) Water Dweller 3)​ He also divided the plants into three groups based off of their stems​ a) Trees​ b) Herbs​ c) Shrubs There were many problems with this system of classification 1)​ Many organisms were being placed into groups in which they had no real relationship with each other 2)​ The use of common names was very confusing, for example catfish, jellyfish and starfish 3)​ Many new organisms were being discovered and needed to be classified The Linnaeus System of Classification: 1)​ Philosopher Carolus Linnaeus set up a classification system based on structural similarity, he thought that organisms that looked alike were the most closely related 2)​ Linnaeus developed a system that placed an organism in a particular group and assigned it a particular name 3)​ He developed a naming system called binomial nomenclature, which is the system of assigning an organism a scientific name 4)​ He first divided all organisms into large groups that he called kingdoms. He based his classification on two kingdoms: The plant and animal kingdom -​ More recently, scientists have developed a broader group; Domain -​ The three types of domain are​ a) Eukarya​ b) Bacteria​ c) Archaea  -​ Bacteria and archaea are both single-cellular organisms, while eukarya contains all organisms with complex, multicellular structures 5)​ The 8 levels of classification: ​ Kingdom → Phylum → Class → Order → Family → Genus → Species -​ A good way to remember this is by saying: Did King Phillip Come Over For Good Spaghetti -​ A species contains only one kind of organism Rules of Binomial Nomenclature: -​ The scientific name are in latin always consists of two words: The genus and the species -​ The first name is always capitalized, while the second name is not, and the two names are always the genus followed by the species Lesson #2 Modern Taxonomy: -​ Phylogeny is the evolutionary history of an organism -​ To show the evolutionary relationship between different groups of organisms, scientists construct a phylogenetic tree -​ A phylogenetic tree is a family tree that shows the evolutionary relationships thought to exist among different groups of organisms Modern Taxonomy: -​ Modern taxonomy is based on the morphology of different species (structure) -​ This was the basis for Linnaeus’ system of classification Homologous Structures Analogous Structures Vestigial Structures Structures in different species that Structures in different species that A structure that is reduced in size are similar because of common are similar in function but not in and seems to be “left over” from a ancestry. structure and are not derived from previous ancestor. For example, the bones found in a common ancestor. For example, the human appendix the wing of a bird, the wing of a For example, the wing of a bird or wisdom teeth. bat, and the forearm of a human. and the wing of a butterfly. -​ The greater number of homologous structures two organisms share, the more closely related they are thought to be -​ Similarity in cell structure provides evidence that organisms may be related -​ Scientists now group organisms into categories that represent lines of evolutionary descent or phylogeny -​ Fossils show that organisms alive today are similar to organisms that are now extinct, for example 25 breeds of dogs all came from a wolf-like ancestor -​ Three easy ways we can tell organisms apart are: Biochemical Similarities Genetic Similarities Embryological Similarities Similarities of chemical Do the two organisms have the Similarities in embryological compounds found within cells can same number or type of development provide evidence of be used as evidence to show chromosomes? phylogenetic relationships relationships between organisms Two organisms that bear no Some organisms show no resemblance to one another similarities as adults, but are very A comparison between the anatomically may still be related similar as embryos. An example of proteins of two organisms occurs to one another. Two organisms this is an amnion which is a as a “molecular clock”. Simple that look nothing alike may still fluid-filled sac that surrounds the mutations occur all the time, have similar genes in their DNA embryos of some vertebrates. The causing slight differences in the This genetic similarity is an embryos of fish and amphibians indication that yeast and humans lack amnion. The embryos of DNA and the proteins being built. share a common ancestor reptiles, birds and mammals When the proteins of two possess an amnion. On the basis different organisms are The more similar DNA sequences of this shaped embryological compared, the number of are within two species, the more structure, reptiles, birds and differences in amino acid recently they shared a common mammals are grouped together sequences is a clue to how long ancestor, the more two species and are referred to as amniotes. have diverged, the less similar their DNA will be  ago two species diverged from a shared common ancestor Cladistics: -​ Cladistics is a relatively new method of classifying organisms -​ Cladistics identifies the characteristics of organisms that are “evolutionary innovations” these innovations are new characteristics that arise among organisms over time -​ Cladistics uses a feature called shared characters and derived characters Shared Characters Derived Characters A feature that all members of the group have in A feature that evolved only within the group under common, for example feathers in birds or hair in consideration, for example feather in birds (since mammals birds are the only animals with feathers, it is assumed feathers evolved within the bird group and were not inherited by an ancestor -​ Shared derived characters are strong evidence of common ancestry between the organisms that share them. Organisms that share one or more derived character most likely have a common ancestor -​ Clades is used to describe a group of organisms that include a ancestor plus all off its descendants, the relationship between the organisms in a clade can be represented by a cladogram (shown below) -​ A cladogram is a diagram that shows the evolutionary relationships among a group of organisms -​ This cladogram shows the relationship between 5 different organisms alive on earth today -​ A cladogram includes an organism that is only distantly related, knows as the “out-group”, in this cladogram the out-group is the Lamprey -​ The other organisms are known as the “in-group” and have one or more of shared derived character -​ The in group of this cladogram is Sea Bass, Antelope, Bald Eagle and  the alligator, which all possess one or more shared derived characters from the lamprey Lesson #3 Kingdoms and Domains -​ A kingdom called the “monera kingdom” was formed in the 1950’s and included bacteria and blue-green algae. These are the simplest of all living organisms. -​ There are currently six known kingdoms, and three domains. The six kingdoms fall into 1 of 3 domains: Kingdom Kingdom Kingdom Kingdom Kingdom Kingdom Archaebacteria Eubacteria Protists Plantae Fungi Animalia Domain Archaea Domain Bacteria Domain Eukarya -​ A kingdom comparison would look something like this:  All Living Things Domain Bacteria Archaea Eukarya Kingdom Eubacteria Archaebacteria Protista Fungi Plantae Animalia Cell Type Prokaryotic Prokaryotic Eukaryotic Eukaryotic Eukaryotic Eukaryotic Cell Thick and rigid Cell walls do Contains Cell walls Cell walls No cell walls Structure cell walls not contain organisms that composed of composed of and no composed of peptidoglycans are neither chitin and cellulose, chloroplasts Peptidoglycans Cell animal, plant have no chloroplasts membranes or fungi chloroplasts are present contain Cell walls unusual lipids composed of not found in cellulose in any other some organisms organisms and “Ancient have organisms” chloroplast and very primitive Cell Unicellular Unicellular Most are Most are Multicellular Multicellular Organization Unicellular Unicellular Food Autotrophs + Includes Autotrophs + heterotrophs Autotrophs heterotrophs Getting heterotrophs Autotrophs + heterotrophs heterotrophs Examples of E-coli, strep Methanogen Amoeba, Mushrooms, Mosses, Mammals, organisms (has no thermophiles algae, slime yeats molds, ferns, fish, birds, nucleus) (has no and mold mildews and flowering reptiles, nucleus) smut plants amphibians -​ Autotroph: An organism that makes it own food (plants through photosynthesis) -​ Heterotroph: An organism that gets its food from other organisms -​ Prokaryotic: A unicellular organism that doesn’t have a nucleus -​ Eukaryotic: A multicellular organism that has a nucleus Factors That Keep Organisms Apart: -​ Physical characteristics: Mating is impossible under natural conditions for most organisms -​ Mating occurs, but the offspring do not survive: bullfrog eggs may be fertilized by the sperm of a leopard frog, the eggs develop to a point but do not survive -​ The offspring may survive, but they are not fertile: Horse + Donkey = Mule -​ Geographical barriers: many organisms simply do not come into contact with one another  -​ Behavioural barriers: Many organisms, especially in the animal kingdom, will not mate unless certain behaviours are exhibited Necessities for Organisms: Nutrition Take in material (i.e.) food for growth Respiration Releases energy from food for cellular process Movement Move using energy consumed by the organism Excretion Release waste products from cellular processes Growth Living organisms use food to grow in size or number of cells Reproduction Produce offspring Sensitivity Sense and respond to stimuli in the environment What is a Virus? -​ Viruses are microscopic particles capable of only reproducing within existing living cells (host cells) -​ Viruses are classified as non-living particles because they cannot perform any of the processes that are the required characteristics of life -​ Viruses do share one characteristic with organisms: they contain genetic material (DNA) that can be passed, however they require a host cell to reproduce Basic Structure of a Virus -​ All viruses contain nucleic acid (DNA or RNA) in core, surrounded by capsid (protein coat) and an outer envelope -​ Viruses are less than 0.1 micrometres in diameter (1 micrometer = (10 to the negative 6m))  -​ Bacteriophages (complex viruses) are viruses that invade and destroy bacteria cells, they have unique shapes and distinct head and tail regions -​ They are the most abundant biological agent on Earth Viral Replication and Transmission -​ There are two different types of ways viruses can replicate within a host cell: Lytic Cycle Lysogenic Cycle In the lytic cycle, the virus hijacks the host cell using In the lysogenic cycle, the virus incorporates its it to reproduce the virus. The host cell is destroyed in genetic material into the host cell’s genome, infecting the process. it from within. The host cell remains intact There are 4 steps to the Lytic Cycle:​ 1) Attachment to host cell In the lysogenic Cycle, the host cell is not destroyed 2) Synthesis of new virus Viral DNA can remain in a dormant state (lysogeny) 3) Assembly of new virus for years, the host continues to divide with viral DNA 4) Release of virus, destroying the cell inserted into its own DNA The lytic cycle can take as few as 25-45 minutes to When triggered by changes, viral DNA becomes produce as many as 300 new viruses. Some examples active, and the virus enters the lytic cycle. Examples are common cold, ebola and SARS include herpes and HPV