Name:
Biology End of Course Exam Study Packet
How do I use this packet?
This packet contains all the information you need to know for the EOC. You should read this packet as many times as possible before the EOC. Use this packet to review and re-learn material. After reviewing, you should test your knowledge by quizzing yourself and answering practice questions from my website. GOOD LUCK!!!
https://sites.google.com/site/solomonsbiologybtw/assignments I. Introduction to Biology
The practice of science
All science must be tested and verified. The major pieces of an experiment are: Independent variable: what you change in an experiment
Dependent variable: what you measure in an experiment
Constants: parts of an experiment that do not change – you only want 2 variables (see above)
Control: a group that is not affected by the independent variable. You use the control group as a comparison
All data collected from an experiment must be analyzed and the original hypothesis must be re-evaluated. Remember, all experiments should be repeatable and other scientists should review the experiment to determine validity.
II. Biological Macromolecules (http://www.chemistry24.com/biology/the-macromolecules.html)
Describe the basic molecular structures and primary functions of the four major categories of biological macromolecules.
Introduction: Living organisms should be able to transform matter and energy into different forms, show response to changes in their environment, and show growth and reproduction. All living organisms undergo changes due to large organic compounds called macromolecules. Four main types of macromolecules control all activities. They are proteins, carbohydrates, nucleic acids and lipids. What are macromolecules? A very large molecule made up of smaller units called monomers. The monomers may be the same or slightly different. Only a few monomers can recombine to create a lot of different combinations—this gives the diversity of macromolecules.
Carbohydrates: Carbohydrates typically have CnH2nOn formula. There are three types of carbohydrates, monosaccharides contain one sugar, disaccharides contain two sugars, and polysaccharides contain many sugars. Polysaccharides play important roles in cells such as energy storage and structure support (plant cellulose).
Proteins: Proteins are made of C, H, O, N and S. The building units of proteins are amino acids. There are 20 different amino acids. When the amino acids come together, they form functional proteins that have a wide variety of functions including: structural proteins, transport proteins, immune system proteins, and enzymes.
Lipids: Lipids are made of carbon, hydrogen and oxygen. Lipids store energy for long periods of time (fat) and are also the major component of the cell membrane.
Nucleic Acids: Nucleic acids are made of carbon, oxygen, hydrogen, nitrogen and phosphate. The basic building blocks of nucleic acids are nucleotides. There are two types of nucleic acids, DNA and RNA. DNA is long, linear double strand molecule; RNA is shorter and single strand. DNA and RNA are genetic material, carrying all the codes for the functioning of the cell. They also have the keys to heredity and the ability to make new cells.
Macromolecule Monomer Elements Functions Examples Image
Proteins Amino Acids C, H, O, N Speed up chemical reactions (enzymes), transport (in the cell membrane), structural, immune system (antibodies), etc
Enzymes (end in -ase), antibodies, collagen
COMPLEX 3 DIMENSIONAL STRUCTRE
Carbohydrates Monosaccharides C, H, O in 1:2:1 ratio 1. Main energy source 2. Short term energy storage
3. Structural
Glucose, cellulose, starch
Pentagon or Hexagon
Lipids Fatty Acids and Glycerol
C, H, and O 1. Long term energy storage
2. Insulation
3. Major component of the cell membrane
Fats, oils Singular head with two or three chains
Nucleic Acids Nucleotides (A,T,C,G, and U)
C, H, O, N, P Stores genetic information
Enzymes: Enzymes are protein catalysts that increase the rate of a reaction by lowering the activation energy. Enzymes are not considered reactants or products of the reaction and are not used up in the reaction – in other words, they are re-useable. Because of the shape of the enzyme, it will only catalyze reactions of the proper substrates (reactants). Each enzyme works best at a specific pH and a specific temperature. If either the pH or temperature is changed, the enzyme will not work as effectively. If they change significantly, they will denature (complex 3D shape falls apart) and cease (stop) functioning all together. Example: the enzymes in your stomach work at very low pH (acidic) but when the food enters the small intestine, the pH changes and the stomach enzymes no longer catalyze reactions.
III. Ecosystems and Energy Flow
-Use a food web to identify and distinguish producers, consumers, and decomposers. Explain the pathway of energy transfer through trophic levels and the reduction of available energy at successive trophic levels.
-Analyze how population size is determined by births, deaths, immigration, emigration, and limiting factors (biotic and abiotic) that determine carrying capacity.
Background Information:
A food chain shows how each living thing gets its food. Some animals eat plants and some animals eat other animals. The arrows in a food web show the energy flow. The point of the arrow is the animal that does the eating because that is the animal that gets the energy. A food chain always starts with plant life and ends with an animal:
1. Plants are called producers because they are able to use light energy from the Sun to produce food (sugar) from carbon dioxide and water.
2. Animals cannot make their own food so they must eat plants and/or other animals. They are called consumers. There are three groups of consumers.
a. Animals that eat ONLY PLANTS are called herbivores (or primary consumers). b. Animals that eat OTHER ANIMALS are called carnivores.
i. Carnivores that eat herbivores are called secondary consumers ii. Carnivores that eat other carnivores are called tertiary consumers 3. Animals and people who eat BOTH animals and plants are called omnivores.
4. Then there are decomposers (bacteria and fungi) that feed on decaying matter. These decomposers speed up the decaying process that releases mineral salts back into the food chain for absorption by plants as nutrients.
In a food chain, energy is passed from one link to another. When a herbivore eats, only a fraction of the energy (that it gets from the plant food) becomes new body mass; the rest of the energy is lost as waste or used up by the herbivore to carry out its life processes (e.g., movement, digestion, reproduction). Therefore, when the herbivore is eaten by a carnivore, it passes only 10% of total energy (that it has received) to the carnivore. Of the energy transferred from the herbivore to the carnivore, some energy will be "wasted" or "used up" by the carnivore. The carnivore then has to eat many herbivores to get enough energy to grow. Because of the large amount of energy that is lost at each link, the amount of energy available decreases as you move up the trophic levels. To obtain more energy, and organism needs to be on a lower trophic level. The further along the food chain you go, the less food (and hence energy) remains available.
NOTE!! Each organism in the food chain is only transferring one-tenth of its energy to the next organism. You can see that because energy is lost at each step of a food chain, it takes a lot of producers to support a few top consumers. If there were 1000 units of energy at the producers level, the primary consumers would receive 100 units of energy, the secondary consumers would receive 10 units of energy, and the tertiary consumer would receive 1 unit of energy.
Succession is the gradual change in ecosystems over time. Ecosystems begin with simple plants (mosses and lichens) and then gradually become more complex over time. The final, most complex ecosystem is called a climax community and full of large trees and many species of plants and animals. Climax communities have a high level of biodiversity. If an ecosystem begins on rock, it undergoes primary succession. If and ecosystem begins on soil, it undergoes secondary succession. Both types of succession result in climax communities, but secondary succession reaches the climax much more quickly.
Distribution of life in aquatic ecosystems: Life is unevenly distributed in aquatic (water) ecosystems. The area where light is present is called the photic zone. Areas where light cannot penetrate are called apothic zones. Photosynthesis can occur in the photic zone. Light and depth are inversely related – light increases as depth decreases. Life and light are directly related – life increases as light increases. Therefore, life and depth are inversely related.
Human Impact on the Environment: It is important to remember that humans have a significant impact on the
environment. Typically, we have a negative impact on the environment but we can also have a positive impact. The questions you will have on the EOC relating to the human impact on the environment require you to understand the question and think logically to arrive at the appropriate conclusion. Essentially, this is cause and effect in biological terms. Below you will find common examples of the Human Impact on the Environment:
Global warming: humans produce large quantities of greenhouse gasses such as methane and carbon dioxide. These gasses cause solar energy (heat) to be trapped in the earth’s atmosphere – this is the greenhouse effect. As a result of the greenhouse effect, the overall temperature of the earth increases – this is global warming. As we produce more gasses and destroy the organisms that absorb these gasses (plants use CO2 for photosynthesis), the effects of global warming will become more severe. Polar ice caps will melt, flooding costal areas while many species will become extinct as they are unable to deal with the environmental changes. In other words, the environment will change too quickly and the species will not have the traits to deal with these changes
Pollution – any toxin (pollutant) we put into the environment
Biomagnification: the buildup of toxins in living organisms. The higher the trophic level of an organism, the more toxin it will have (mercury builds up until tuna have concentrations of mercury potentially dangerous to humans)
Eutrophication: usually caused by fertilizer run-off, eutrophication is the buildup of organisms as a result of excess nutrients. This depletes resources from the organisms that are supposed to live in the ecosystem
Deforestation: process of destroying forests. This causes a world-wide decrease in the rate of photosynthesis, thus increasing the effects of global warming. Deforestation also destroys habitats and decreases biodiversity
Invasive species: As a result of humans, animals AND plants are put into ecosystems where they do not belong. As a result, the organisms do not have any natural predators and could out-compete the native (indigenous) species. This decreases biodiversity and is very bad for the ecosystems because they are so delicate!
IV. Cell Structures and Functions
-Describe the scientific theory of cells (cell theory) and relate the history of its discovery to the process of science.
-Compare and contrast the general structures of plant and animal cells. Compare and contrast the general structures of prokaryotic and eukaryotic cells.
There are 3 parts to the cell theory:
1. Cells are the basic structural and functional unit of life 2. All living things are made of cells
3. Cells can only come from pre-existing cells.
Scientists used to think that cells could form spontaneously – this idea has since been removed because of the evidence suggesting that cells come from pre-existing cells. Any finding that refutes any of the tenets of the Cell Theory will cause it to change. For example, if life is found that is made up of something other than cell or if cells are observed coming from non-cells, the Cell Theory would need to be modified.
Eukaryotes are more complicated cells that have a nucleus and other membrane-bound organelles. The DNA of eukaryotic cells is located within the nucleus. There are two types of eukaryotic cells – plant cells and animal cells. Plant cells have three more structures than animal cells: cell wall, central vacuole, and chloroplasts. See table below:
Organelle Prokaryote
Or Eukaryote
Plant or Animal Cell
Function
Nucleus Eukaryote Both Holds the DNA (genetic information) of cells – has a membrane that allows RNA to be transported in and out
Ribosome Both Both Where proteins are made during translation
Mitochondria Eukaryote Both Cellular respiration occurs here to produce ATP this is the power house of the cell
Chloroplast Eukaryote Plant Photosynthesis occurs here in plant cells Endoplasmic Reticulum
(ER)
Eukaryote Both “highway of the cell” and site of protein and lipid synthesis
Golgi body Eukaryote Both Sorts and packages cellular products like the post office of the cell Lysosome Eukaryote Both Breaks down waste products
Cell Wall Both Plant Protects plant and some prokaryotic cells; supports cell Vacuole Eukaryote Plant Stores water and waste, supports cell to make it rigid
Cell Membrane Both Both Controls what enters and exits a cell. It is made up of a lipid bilayer that is selectively permeable (only small and non-polar molecules can pass through it). Large and/or charged molecules must go through transport proteins embedded in the membrane. Passive transport does not require energy (high concentration to low concentration). Active transport requires energy (low concentration to high concentration)
Cytoplasm Both Both The water-like substance that takes up most of a cell
V. Cellular respiration and Photosynthesis
-Relate the structure of each of the major plant organs and tissues to physiological processes. -Explain the interrelated nature of photosynthesis and cellular respiration.
Photosynthesis occurs in the leaves of plants and in some bacteria. The goal of photosynthesis is to create glucose. Carbon dioxide, sunlight, and water are used to make glucose and oxygen. Sunlight is a form of energy.
CO2 + H20 + Sunlight Glucose + O2
Cellular respiration occurs in all living organisms. There are two types of cellular respiration: aerobic and anaerobic. Aerobic respiration requires oxygen and glucose. Aerobic respiration has three stages: glycolysis, the Krebs cycle, and the electron transport chain. This produces 36 ATP molecules. ATP is a form of energy.
Glucose + O2 CO2 + H20 + ATP
Photosynthesis and aerobic respiration are opposite processes. They both exchange gasses (carbon dioxide and oxygen) but photosynthesis uses energy from the sun to store energy in glucose. Respiration uses glucose to produce ATP. The products of photosynthesis are the reactants for cellular respiration; the products of aerobic respiration are the reactants for photosynthesis. There two processes cannot exist without the other.
Anaerobic respiration also produces ATP, but much less of it. Anaerobic respiration occurs when there is glucose, but no oxygen. Like aerobic respiration, anaerobic respiration begins with glycolysis, but then goes through fermentation in place of the Krebs cycle and the electron transport chain. One type of anaerobic respiration produces lactic acid, the other produces ethanol
Glucose ATP + Lactic Acid (causes your muscles to be sore) Or
Glucose ATP + CO2 + Ethanol (used in brewing industry) Major plant organs, tissues, and structures
Organs
o Roots: absorb water and nutrients from soil
o Flowers: flowers are the reproductive structures of angiosperms. Cones are the reproductive structures of gymnosperms. Both angiosperms and gymnosperms produce seeds nut angiosperms are flowering plants
Tissues
o Dermal: The outer layer of the plant
o Vascular: the “highway” of the plant that’s transports water and nutrients through the plant. The Xylem carries water from the roots to the leaves while the phloem carries nutrients both to and from the leaves and roots
o Ground: The support system of the plant, stores carbohydrates (the products of photosynthesis)
o Meristematic: This tissue is found in the roots of the plant – this is where new cells are formed. These cells and general cells with no function – they are then converted into whatever type of cell that the plant needs
Structures
o Stoma: Small openings on the underside of leaves that open of close to exchange the gasses of photosynthesis. When water needs to be conserved, the stoma are closed and not photosynthesis can occur.
o Guard Cells: Cells that surround the stoma and control when it is open or closed. The purpose of the guard cells is to prevent transpiration (loss of water from a plant)
o Waxy Cuticle: A layer of wax covers the tops of leaves to prevent transpiration
VI. Mitosis and Meiosis
-Compare and contrast mitosis and meiosis and relate to the processes of sexual and asexual reproduction and their consequences for genetic variation.
Mitosis and meiosis are the two forms of cell division. Both begin with a diploid cell (two copies of every chromosome) and require the entire DNA to be replicated before they begin (duplicate each homologous chromosome so that it is made of 2 identical sister chromatids). Before each one begins, the cells go through Interphase where the DNA is replicated
Mitosis: Mitosis occurs in somatic (body) cells and results in two identical diploid cells. Mitosis is a form of asexual reproduction, meaning there is NO genetic variation between the two cells
Prophase: chromosomes appear (already duplicated), spindle fibers form, nuclear membrane breaks down Metaphase: All chromosomes line up in a straight line called the metaphase plate
Anaphase: SISTER CHROMATIDS begin to separate
Telophase and Cytokinesis: sister chromatids continue to separate and the cytoplasm divides; nuclear membrane reforms. THE FINAL PRODUCTS ARE TWO IDENTICAL DIPLOID CELLS
Meiosis: This is cell division that results in the formation of gametes (sperm or eggs). The final products of meiosis are 4 different haploid cells. Meiosis has 2 phases of cell division. Meiosis is sexual reproduction because there is genetic variation. This genetic variation is caused by crossing over between homologous chromosomes and independent assortment of chromosomes during metaphase I. It is important that each sperm and each egg has only 1 copy of each chromosome (haploid) so that when the fuse, the resulting cell is diploid. If nondisjunction occurs during meiosis, the chromosomes fail to separate – this can result in severe mental retardation or death (nondisjunction of chromosome 21 causes Down’s Syndrome).
Meiosis I: Begins with diploid cell
Prophase I: chromosomes appear (already duplicated), spindle fibers form, nuclear membrane breaks down. Homologous chromosomes form tetrads and crossing over occurs between homologous chromosomes (increases genetic variation) Metaphase I: Homologous chromosomes (the same chromosome, but they are not identical – one version of the chromosome
is from the mother and the other from the father. They have the same genes, but different copies of the gene) line up in PAIRS. There is an equal chance that the chromosome will be on the left as on the right. This is called independent assortment and increases genetic variation.
Anaphase I: HOMOLOGOUS CHROMOSOMES begin to separate.
Telophase I and Cytokinesis: Homologous chromosomes continue to separate and the cytoplasm divides; nuclear membrane reforms. THE FINAL PRODUCTS MEIOSIS I ARE TWO DIFFERENT HAPLOID CELLS
Meiosis II: Occurs in two haploid cells at the same time Prophase II: Chromosomes re-appear
Metaphase II: Chromosomes line up in a straight line Anaphase II: SISTER CHROMATIDS begin to separate
Telophase II and Cytokinesis: sister chromatids continue to separate and the cytoplasm divides; nuclear membrane reforms. THE FINAL PRODUCTS ARE DIFFERENT HAPLOID GAMETES (cells).
VII. Genetics
-Use Mendel’s laws of segregation and independent assortment to analyze patterns of inheritance.
Humans have somewhere between 20,000 and 30,000 genes between our 23 chromosomes. We have two copies of every
chromosome (diploid), meaning that we have 2 copies of every gene. Each different form of a gene is called an allele, and we can have the same alleles or different alleles for each gene. If the alleles are the same, we are referred to as homozygous; if the alleles are different we are referred to as heterozygous. Your genotype describes the genes you have; the phenotype is the physical appearance a. Dominant and Recessive Inheritance
This is the most basic form of inheritance. In this case, one dominant allele is enough to show the dominant phenotype. For example, TT and Tt would indicate a tall plant while tt would indicate a short plant. The heterozygous genotype has the same phenotype as the homozygous dominant genotype. It is only possible to show the phenotype with two recessive alleles. EXAMPLE: two heterozygotes are crossed:
A dihybrid cross involves two genes and is done the exact same way as a basic dominant recessive cross.
b. Polygenic Inheritance
Traits that are affected by many genes are called polygenic traits. Because these traits are controlled by many genes, the traits show a large spectrum of characteristics with most individuals expressing an intermediate phenotype. For example, skin color is a polygenic trait
c. Codominance:
Codominance occurs when both alleles are dominant -- this means that if both alleles are present, both alleles will be expressed (as opposed to only one allele). For example, if flower color is codominant and the alleles are red and white, a flower could be red (RR), white (WW), or red AND white (RW). You could show it as red (RR), white (rr) or red and white (Rr). Remember what your letters represent! The heterozygous genotype has a phenotype that shows both parental phenotypes
d. Incomplete Dominance:
Incomplete dominance occurs when neither allele is dominant to the other. Instead, the alleles in combination show an intermediate trait. For example, if flower color is incompletely dominant and the alleles are red and white, a flower could be red (RR), white (WW), or red AND white (RW). You could show it as red (RR), white (rr) or red and white (Rr). The heterozygous genotype has a phenotype that is a blend of the two parental phenotypes.
EXAMPLE: Black and white are incompletely dominant. Two gray individuals are crossed:
e. Sex-linked inheritance
Chromosomes 1-22 are known as autosomes – males and females have the same genes on these chromosomes. The 23rd chromosome is the sex chromosome. Women are XX while men are XY. Men are more likely to show sex-linked recessive traits because they only have one X chromosome. A female may have the recessive allele, but it may be hidden by the dominant allele on the other X chromosome. For a recessive trait, women can be normal (XX), carriers of the recessive trait (XXC), or show the trait XCXC). Men are either unaffected (XY) or show the recessive trait (XCY). When solving problems, determine whether the question is asking about a child (use all four boxes in the Punnett square to determine probability) or a specific sex (only look at the two boxes in the Punnett square that are the same sex.
EXAMPLE: a carrier female of a X-linked recessive disorder and an unaffected male have a child:
f. Genetic Disorders
Genetic disorders are inherited, not acquired. Many genetic disorders cause death before birth. Nondisjunction occurs when homologous chromosomes fail to separate during meiosis I, causing a gamete to be diploid or have no chromosomes are all. When this gamete fuses with a normal gamete, the resulting zygote has 3 copies of the chromosome (trisomy) or one copy (monosomy). An example of this is Down’s Syndrome (trisomy 21). Translocation occurs when non-homologous chromosomes crossover. Inversion occurs when sections of chromosomes are cut out and replaced in the opposite orientation as normal. Duplication occurs when sections of DNA are duplicated. All of these genetic disorders have serious implications for the health of the child.
VIII. DNA, Transcription, and Translation
Describe the basic process of DNA replication and how it relates to the transmission and conservation of the genetic information. DNA is the molecule that stores the genetic information of an organism. In eukaryotes, the DNA is located in the nucleus and separated into chromosomes; in prokaryotes the DNA is in a small circular shape called a plasmid located in the cytoplasm. DNA is a double stranded helix made of four nucleotides: adenine, guanine, cytosine, and thymine. Adenine and guanine are purines while thymine and cytosine are pyrimidines. The backbone (think the sides of the ladder) are made up of alternating sugars and phosphates. The rungs of the ladder are the bases. Adenine always pairs with thymine while cytosine always bonds with guanine (A=T and C=G). RNA is single stranded and replaces thymine with uracil.
Our DNA is composed of genes, and these genes code for the genetic information to make proteins. DNARNAProteins. Transcription is the process of making mRNA from DNA. RNA polymerase unwinds the section of DNA that needs to be transcribed and forms the mRNA. This final mRNA then exits the nucleus and goes to the ribosomes where translation occurs. Translation is the process of making proteins from the mRNA. The mRNA moves through the ribosome. Every three nucleotides on the mRNA is known as a codon and codes for one amino acid (one codon=one amino acid). tRNA molecules carry specific amino acids on one end, and have a three-base anticodon on the other. In the ribosome, the mRNA codon binds with the tRNA anticodon. The amino acid attached to the tRNA is then added to the growing amino acid chain (protein). There is more than one codon for each amino acid. When all of the amino acids have been added, the protein folds into the correct shape and the mRNA is degraded.
Genes are not always expressed. In eukaryotes, each cell has the entire organism’s DNA. However, only some genes need to expressed in any given cell (for example, you do not want to express the genes for stomach enzymes in your brain cells Gene
regulation in eukaryotes is very complicated. In prokaryotes, all genes are expressed because prokaryotes are unicellular.
IX. Evolution
-Describe the scientific explanations of the origin of life on Earth.
-Describe the conditions required for natural selection, including: overproduction of offspring, inherited variation, and the struggle to survive, which result in differential reproductive success.
-Explain how the scientific theory of evolution is supported by the fossil record, comparative anatomy, comparative embryology, biogeography, molecular biology, and observed evolutionary change.
Early earth was very different than it is today. There was no oxygen in the atmosphere and the conditions were very harsh. Given the conditions of early earth, Miller and Urey showed that organic molecules, specifically amino acids, could spontaneously (randomly) form. This had to occur before the first cells could form and is called chemical evolution. The first cells that formed were anaerobic, heterotrophic prokaryotes. These cells then mutated and became anaerobic, autotrophic prokaryotes. These cells began filling the atmosphere with oxygen, allowing aerobic prokaryotes to evolve. Oxygen was a major driving force in evolution. According to the Endosymbiotic Theory, groups of prokaryotes that worked together and eventually formed the first eukaryotes. REMMEBER, PROKARYOTES CAME BEFORE EUKARYOTES.
In the early 1800’s, Charles Darwin formulated his theory of evolution by natural selection. Darwin stated that organisms alive today descended, with modification, from a common ancestor. Evolution is the change in the traits (gene frequency) of a species over time. In other words, the DNA of an organism changes over time. According to Darwin, there are four conditions necessary for evolution to occur:
1. Individuals in a population have different traits – in other words, each individual is BORN with different adaptations 2. Species produce more offspring than the environment can support
3. Because of the overpopulation, there is a struggle for existence among the individuals
4. Survival of the fittest – the organisms born with best adaptations will survive and pass on their traits while the organisms without the best adaptations will die and not pass on their traits
This is Evolution by Natural Selection
Example: bugs can be either black or white. The bugs live in the snow. The white gene would be selected for because it is harder for the predator to see the white bugs. As a result, the frequency of the white gene increases while the frequency of the black gene decreases.
Natural selection is caused by an environmental limitation. It is not, however, the only cause of evolution. Genetic drift is the random change in gene frequency. For example, if a flood comes and kills all the black bugs, the frequency of the black gene decreased but NOT as a result of natural selection. Rather, this is evolution caused by genetic drift. Gene flow, which is the exchange of genes between populations, and mutations, which are random changes in DNA, also cause changes in gene frequency and therefore are other causes of evolution.
Evolution acts on an entire species, natural selection works on the individuals of a population. Genetic variation is good for the survival of a species. If the species has genetic variation, it is more able to survive some type of environmental catastrophe. For example, if there is a drought that causes the food supply to change, the individuals that can eat the new food supply will survive. If all of the individuals were identical, no traits would be selected for and the entire species would die out.
There are three types of selection that act on polygenic traits: stabilizing, disruptive, and directional. Stabilizing selection occurs when the intermediate phenotype of a population is favored over the extreme phenotypes. As a result, organisms with this intermediate phenotype are more reproductively successful and become a higher percent of the population. Disruptive selection is the opposite – both extreme phenotypes are favored over the intermediate phenotype. As a result, the extreme phenotypes become a higher percentage of the population while the percent of individuals with the intermediate phenotype decreases. Directional selection occurs when one of the extreme phenotypes is favored – the average phenotype within the population becomes this extreme
phenotype.
Convergent evolution occurs when two species that are distantly related begin to have similarities as a result of their environment. For example, dolphins and sharks have many similarities despite the fact that they are no closely related from an evolutionary perspective. This results in analogous structures. Coevolution occurs when two species interact so closely that one species impacts the evolution of the other (think flowers and bees). Divergent evolution occurs when populations of one species are separated from one another. As a result of the separation, the two populations begin to follow different evolutionary paths. This could cause speciation and result in the two different species having homologous structures.
diverge to the point where they can no long reproduce and produce fertile offspring, they are two different species. Speciation has occurred. According to punctuated equilibrium, there are long periods of time where no new species are formed (but the gene pools of the two populations are diverging), then abruptly, a new species forms. If many new species form in a very short period of time, it is referred to as adaptive radiation.
Hominid evolution is marked by several trends that have evolved and allowed humans to develop into the beings that we are today. To make it very clear, we did not come from monkeys. Monkeys and humans share a common ancestor, but were exposed to different evolutionary forces (selection, mutations, genetic drift) and diverged, becoming distinct species. Over time, the major trends of human evolution are:
Bipedalism (walking on two feet) Decreased jaw size/jaw muscle size Decreased “eyebrow” bone Increased brain size
o Allowed for more complex society that included speech and tools
Scientists use several different parts to support the theory of evolution by natural selection. All of these pieces of evidence support the idea that all living organisms come from a common ancestor.
Fossils
o Provide evidence that organisms have changed through time. Biogeography
o Study of past and present distribution of species. Gives us clues to the evolution of species. Comparative anatomy – organisms with anatomical similarities are closely related
o Homologous structures – structures that are similar because of common ancestry.
o Analogous structures – similarities are due to adaptation to similar environments not common ancestry. o Vestigial structures –structures of little or no use to the organism.
Comparative embryology
o Closely related organisms go through similar stages in their embryonic development and therefore have similarities in the early stages od development.
Molecular biology –related species have a DNA and proteins in common.
o The more similar the organisms, the more similar their DNA and proteins
o All living organisms use the same genetic code (A,T,C,G) and nearly all codons for living organisms is the same
X. Taxonomy
Discuss distinguishing characteristics of the domains and kingdoms of living organisms.
Taxonomy is the science of classifying organisms based on their evolutionary relationships. Scientists do this to avoid any confusing when discussing organism. As new evolutionary evidence is found, the classification of an organism may change. For example, fungi and plants were once considered part of the same kingdom. However, when it was discovered that fungi are heterotrophs and not autotrophs, the classification system changed and kingdom fungi appeared. From most general to most basic, the classification system is: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species. As you get closer to species, the number of organisms decreases. The more closely related organisms are, the more classifications they will share.
Domain: Archea Bacteria Eukarya
Kingdom: Archeabacteria Eubacteria Protista Fungi Plantae Animalia
Cell Type Prokaryote Prokaryote Eukaryote Eukaryote Eukaryote Eukaryote
Number of cells Unicellular Unicellular Mostly
unicellular
Mostly multicellular
Multicellular multicellular
Structure of cell Wall Cell wall without peptidoglycan
Cell wall with petidoglycan
Some have cell walls, some do
not
Cell walls made of chitin
Cell walls made of cellulose
No cell wall
Mode of Nutrition Autotrophs and heterotrophs Autotrophs and heterotrophs Autotrophs and heterotrophs Heterotrophs, absorb nutrients with filaments Autotrophs, perform photosynthesis Heterotrophs, ingest nutrients
Other Characteristics Live in extreme places
Very diverse Decomposers in
ecosystems
Examples Organisms that live in extreme places
bacteria Algae, protozoa Mushrooms,
mold, yeast
Tree, plants All animals
XI. Human Body Systems
-Identify the major parts of the brain on diagrams or models
-Describe the factors affecting blood flow through the cardiovascular system.
-Explain the basic functions of the human immune system, including specific and nonspecific immune response, vaccines, and antibiotics.
-Describe the basic anatomy and physiology of the human reproductive system. Describe the process of human development from fertilization to birth and major changes that occur in each trimester of pregnancy.
Immune System:
Scientists use antibiotics and vaccines to help protect people from infection. When you receive a vaccine, a small amount of a virus, a deactivated virus, or the antigens of a pathogen are injected into your body to trigger the primary response. This way, if you are infected by the full-blown virus, your secondary response kicks in and you fight off the virus without getting sick. Antibiotics work by killing bacteria in your body. It is important that all of the pathogenic bacteria are destroyed – if not, some may become resistant to the antibiotic (evolution).
Factors that affect blood flow: Blood flows through your cardiovascular system to deliver oxygen and nutrients to your cells while removing waste products from your cells. Blood flow is very important and can be affected in many ways.
Increased heart rate = increased blood flow
Blood Pressure: increase pressure = increased blood flow Blood Volume: decreased volume = decreased blood flow Resistance: Increased Resistance = decreased blood flow
◦ Misshapen blood cells
◦ decreased volume
◦ Disease
◦ Increased viscosity (thickness)
◦ Longer veins/arteries
Disease: narrows blood vessels and increases both the pressure and the resistance Heart must work harder to deliver blood – decreased blood flow
◦ Atherosclerosis is the hardening of arteries. When these arteries harden, blood pressure increases and blood flow decreases
A heart attack occurs when there is a blockage in one of the arteries delivering blood to the heart. A stroke is a blot clot in the brain
To answer these questions, you have to think logically! If something bad is occurring, then pressure will likely increase while blood flow will likely decrease.
Diagram of the brain:
The pons and the medulla together are referred to as the brain stem. You must be able to identify the different parts of the brain in every orientation of the brain! Always determine which way the brain is facing FIRST!
Reproductive System: Males and females have unique reproductive systems that work together to allow for fertilization. After fertilization, it is the female reproductive system allows for the development of the embryo.
Male Reproductive structure: Sperm are produced from meiosis (sperm are haploid) in the testes of the male. The testes are located in the scrotum and also produce testosterone. The sperm then move to the epididymis where sperm mature and develop motility (the ability to move with their flagella). They are stored there until ejaculation, where they travel from the epididymis, through the vas deferens, mix with fluid produced by the prostate and seminal vesicle, and then out of the body through the urethra located inside of the penis. The semen is deposited in the cervix (barrier between the vagina and the uterus) of the female, where it then must travel up through the uterus and into the oviduct (fallopian tube) to fertilize an egg (ovum).
Female Reproductive Structures: Females produce (via meiosis) and store their eggs in their ovaries. Ovaries also produce estrogen. Once a month, and egg is released into the oviduct (also known as the fallopian tube). Fertilization occurs in the fallopian tube. If fertilization does not occur, the unfertilized egg passes through the female reproductive system and exits the body
(menstruation). If fertilization does occur, the fertilized egg is now diploid and referred to as a zygote. When the zygite implants into the uterus, it is referred to as an embryo. The placenta develops to allow for gas and oxygen exchange between the embryo and the mother. The umbilical cord connects the embryo to the placenta. An amniotic sac, filled with amniotic fluid, forms around the embryo to protect it.
Development: The zygote travels through the oviduct and undergoes cell division (mitosis) and implants into the uterus. Once implanted into the uterus, it is referred to as an embryo. The first three months are known as the first trimester. This is the most delicate time for the embryo – the embryo can be most affected by poisons and toxins. During the first trimester, the major organs develop and the heart begins to beat. At the end of the first trimester, the embryo is referred to as a fetus. During the second
trimester, the fetus continues to develop and grow – this is the time when the fetus moves the most. During this trimester, the fetus is covered with hair-like structures called languno. During the third trimester, movement decreases, development continues, and the immune system develops. Lungs develop last as they are useless in the womb. Prior to birth, the fetus arranges itself in the proper orientation. During birth, the amniotic sac breaks, the uterus contracts, and birth occurs through the vagina.
XII. Water
Discuss the special properties of water that contribute to Earth’s suitability as an environment for life: cohesive behavior, ability to moderate temperature, expansion upon freezing, and versatility as a solvent.
Water is a polar molecule, meaning that there is an unequal distribution of electrons within the molecule. The oxygen has a partial negative charge while the hydrogen atoms have partial positive charges. When the y get close enough, they attract each other and form hydrogen bonds.
Hydrogen bonds give water its special properties! 1. Cohesive Behavior:
Cohesion: Water molecules stick to other water molecules because of the hydrogen bonds
Adhesion: Water molecules stick to other substance because of the interactions of the polar substance
Capillary Action: A combination of cohesion and adhesion that allows water to move against gravity. Very important for plants to move water from the roots to the leaves
Surface Tension: Because of the hydrogen bonds on the surface of the water, it is hard to break the surface of water. This allows some insects to walk on water
2. Universal Solvent: Water has the ability to dissolve many substances. Polar substances, like salt, can dissolve in water. Nonpolar substances, like oil, cannot dissolve in water. “Like dissolves like.”
3. Ability to moderate temperature: Water has a high heat capacity meaning it takes a lot of energy to change its temperature, This explains why sand is hotter than water at the beach and why areas close to water, like Miami, experience smaller changes in temperature between night and day than places far from the water.
