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Week 2: Review for the Biology End of Course Exam
Part 1: Matter and Energy Transfer
1. Describe the basic molecular structures and primary functions of the four major categories of biological macromolecules. • Carbohydrates
o A group of organic compounds that includes sugars, starches, and celluloses. They serve as a major energy source for cells.
• Proteins o Organic compounds made of amino acids arranged in a linear chain and folded into a
globular form. They are responsible for a variety of specific and unique functions within a cell.
• Lipids o Biological macromolecules made up mostly of carbon and hydrogen atoms; including fats,
steroids, and oils. • Nucleic Acids
o Biological macromolecule such as DNA and RNA that is made up of nucleotides and contains genetic material.
Biological Macromolecule What they’re made of Functions Examples
Carbohydrates Monosaccharides Energy, structure (cellulose and chitin)
Glucose (monosaccharide) Sucrose & Maltose (disaccharide),
Starch & Cellulose (polysaccharide)
Proteins Amino Acids Structure, movement, defense (antibodies),
signaling, etc.
Hormones like insulin Enzymes
Lipids NA Fats-‐stored energy and insulation
Phospholipids-‐cell membranges
Fat Phospholipids
Steroids like hormones & cholesterol
Nucleic Acids Nucleotides Genetic information DNA RNA
• Enzyme o A special protein used to increase or decrease the rate of a reaction by changing the amount of
energy needed to get the reaction started
o NOT USED UP IN THE REACTION
It is unchanged and can be used again
o Sensitive to temperature and pH; only work when conditions are right
ANSWER:
2. Explain the interrelated nature of photosynthesis and cellular respiration. • Photosynthesis
o A chemical process in which plants use light energy to convert carbon dioxide and water into carbohydrates and stored chemical energy.
o Takes place in the chloroplasts of plants o Light-‐Dependent Reaction
The steps in photosynthesis that convert solar energy to the chemical energy in ATP and NADPH, giving off oxygen in the process.
o Light-‐Independent Reaction The second of two major stages of photosynthesis (following the light: dependent
reactions), also called the Calvin cycle. This stage of photosynthesis uses atmospheric CO2 and the energy from ATP and NADPH to build carbohydrate molecules.
• Cellular Respiration
o A process that releases stored energy from food, using oxygen as a reactant and giving off carbon dioxide as a product.
o Occurs in the mitochondria of the cell
o
As food travels through the digestive system, it is exposed to a variety of pH
levels. The stomach has a pH of 2 due to the presence of hydrochloric acid (HCl), and the small intestine has a pH ranging from 7 to 9. HCl converts pepsinogen into pepsin, and enzyme that digests proteins in the stomach. Which of the
following most likely happens to pepsin as it enters the small intestine?
A. It becomes inactive B. It begins to replicate. C. Its shape changes to engulf large proteins.
D. Its activity increases to digest more proteins.
Photosynthesis
6CO2 + 6H
2O + light energy → C
6H12O
6 + 6O
2
Reactants: Carbon Dioxide + water + sunlight Products: Glucose + oxygen
Cellular Respiration
C6H12O
6 + 6 O
2 → 6 CO
2 + 6 H
2O + Energy
Reactants: glucose + Oxygen Products: carbon dioxide + water + Energy ATP
o Glycolysis The first stage of cellular respiration or fermentation, in which one glucose
molecule is broken down into two pyruvate molecules. o Krebs Cycle
The second stage in cellular respiration, in which pyruvate is broken down into carbon dioxide in a series of reactions.
o Electron Transport Chain A series of electron transport proteins that shuttle high: energy electrons to
an electron: carrier molecule, producing ATP molecules in the process.
Break down glucose and make ATP
Makes
more ATP
Note: for 1 glucose molecule, gylcolysis makes 2 ATP, the Kreb’s cycle makes 2 ATP, and
the Electron Transport chain makes 26+ ATP (for a total of more than 30 ATP)
ANSWER:
3. 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
o H2O o Water is a polar molecule. The covalent bond between oxygen and hydrogen means that
the electrons are shared unevenly and so there is a partially positive (hydrogen) and a partially negative end (oxygen).
o Positive + negative = attraction o This hydrogen bonding (a weak attraction between the oxygen of one atom and the
hydrogen of another) results in many of the unique properties of water • Cohesion
o The clinging of something to itself, or the attraction between molecules of the same substance.
o One water molecule clinging to another water molecule • Adhesion
o The clinging of a substance to another substance, or the attraction of one type of molecule to another type of molecule.
• Specific Heat o The amount of heat energy needed to raise the temperature of 1 gram of a substance by 1
degree Celsius. o The high specific heat and high heat of vaporization means that water is good at absorbing
heat and moderating temperature
• Surface Tension o like an invisible film on the surface -‐ you can see this when you over fill a glass of water
The diagram below shows the relationship between photosynthesis and cellular respiration and the organelles in which they occur.
Which statement describes how photosynthesis and cellular respiration are
interrelated? A. Oxygen is produced during cellular respiration and stored during
photosynthesis.
B. Carbon dioxide and water released by cellular respiration are used in photosynthesis.
C. Photosynthesis releases the energy that is stored during the process of cellular respiration.
D. Glucose is used during cellular respiration to produce food that is
broken down during photosynthesis.
• Expands When Freezing o the hydrogen bonds make a rigid structure that takes more space. It’s also less dense.
• Universal Solvent o ionic compounds and polar molecules in particular dissolve well (because of positive and
negative charges)
ANSWER:
Part 2: Organization and Development of Living Organisms
1. Explain how the scientific theory of evolution is supported by the fossil record, comparative anatomy, comparative embryology, biogeography, molecular biology, and observed evolutionary change.
• Scientific theory of evolution o the processes that transform life on Earth from its earliest forms to the vast diversity on
Earth today • Evidence of the Theory of Evolution
o Fossil Record
o Comparative Anatomy
Water is essential for life. Its special properties make water the single most important molecule in plant life. Which of the following properties of water enables
it to move from the roots to the leaves in plants?
A. Water expands as it freezes.
B. Water is an excellent solvent.
C. Water exhibits cohesive behavior.
D. Water is able to moderate temperatures.
o Comparative embryology
o Biogeography
ANSWER:
2. Describe the conditions required for natural selection, including: overproduction of offspring, inherited
variation, and the struggle to survive, which result in differential reproductive success. • Darwin’s conclusions:
o Natural Selection – populations change becoming better adapted to their environment gradually over many generations.
The scientific theory of evolution is supported by different types of evidence. The diagrams below show the skeletons of two different animal species.
How does comparing the skeletons of these animals provide support for the scientific theory of evolution?
A. It provides information about the organisms’ habitats. B. It shows possible common ancestry between organisms.
C. It provides information to determine the organism’s age. D. It shows possible chromosomal similarities between organisms.
o -‐populations evolve, individuals
do not o -‐variation occurs naturally
within a population (so some
will be better adapted than others)
o -‐adaptations help individuals
survive (those that are better adapted are more likely to survive and reproduce)
o -‐beneficial adaptations will become more common in a pop
o Species can evolve into a new
species over many generations
ANSWER:
Part 3: Interdependence
1. Analyze how population size is determined by births, deaths, immigration, emigration, and limiting factors (biotic and abiotic) that determine carrying capacity.
• Population Dynamics o the study of change in population size and composition.
o Factors that affect populations Births & Deaths
• An organism’s natural rate of reproduction, the ratio of males and females in the population, and the general health of reproducing species directly
impacts the birthrate of a species Immigration and Emigration
• The movement of organisms into (immigration) and out of (emigration) a population
Biotic and Abiotic Factors
Over time, the climate of an island became drier, which resulted in changes to
the populations of various island finch species. Finch populations with a certain beak shape thrived, while those not having a beak shape decreased. Which of the following describes a necessary condition for these changes in the finch
populations to occur? A. Fewer mutations
B. Limited food resources C. Limited beak variations D. Overproduction of offspring
• Biotic
o factors in an environment relating to, caused by, or produced by living organisms.
• Abiotic o an environmental factor not associated with or derived from living
organisms. • Carrying Capacity
o the number of species a region can support
ANSWER:
2. 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.
• Food Web Vocabulary
o Producers
an organism, usually a plant or bacterium, that produces organic compounds from simple inorganic molecules and
energy (typically light energy) from the environment. o Consumers
an organism that feeds on other organisms for food. o Decomposers
any organism that feeds or obtains nutrients by breaking down organic matter from dead organisms.
• 10% Law
o As the energy passes from level to level, less and less usable energy is available to organisms at the higher levels.
The number of pythons found throughout the Everglades National Park has increased in recent years. These huge snakes are not native to Florida and are believed to have been
released into the wild by pet owners. Wildlife biologists have initiated attempts to capture and remove these pythons. Which statement best explains the biologist’s reason for removing these pythons from the Everglades?
A. The pythons could upset the territorial boundaries of native organisms. B. The pythons could adapt to overcome disease common to native snakes.
C. The pythons could prey on native organisms and cause native populations to decline.
D. The pythons could begin to interbreed with native snakes and produce more
successful species.
o Biologists estimate that on average only 10% of the plant's accumulated energy is passed on to the body of the organism that eats it.
o Some is used for digestion, work, growth, and reproduction but only about 10% remains in the tissue of the animal that ate it.
o The rest of the energy is dissipated as heat.
ANSWER:
3. Predict the impact of individuals on environmental systems and examine how human lifestyles affect
sustainability. • The Greenhouse Effect
o Environmental indicators, such as rising ocean temperatures, suggest that human activities are changing our global climates
A team of ecologists observed feeding patterns of several populations in the desert. The energy pyramid shown below depicts the feeding patterns the ecologists observed
A. There is less energy available in the producers because their tissues are less
dense than at higher trophic levels.
B. There is more energy available in the second trophic level because less energy is needed for hunting compared to the higher trophic levels.
C. There is more available energy in the birds of prey because they have greater
muscle mass for storing energy than organisms in lower trophic levels have. D. There is less available energy in the fourth trophic level because of the loss of
energy through metabolism in each of the lower trophic levels.
o • Environmental Indicators of Climate Change
o land temperatures, precipitation levels, large storm frequency, ocean temperatures, sea
levels, ocean currents, ocean composition, glacier recession, polar ice levels, animal migration, plant hardiness zones, and flower bloom rates over long periods to detect
patterns of climate change within world ecosystems. • Our Impact on Ecosystems
o Human Expansion
The growth of our population has required an expansion of our habitat. Human expansion, and subsequent destruction of animal habitat, occurs daily in
local communities and on a greater scale globally. o Our Choices
Our choices affect ecosystems in big and small ways. The pesticides we use on gardens kill insects we consider pests, but it can also kill
some reptiles and amphibians that are natural pest reducers, such as lizards and frogs.
The fertilizers used by farmers can flow into local lakes and rivers with the rain, depositing nitrogen compounds that deplete oxygen levels in the water.
Municipal and industrial wastewater systems, septic tanks, and discharges from car exhausts also deposit nitrates into freshwater and marine ecosystems. These
pollutants cause fish kills and brown blood disease in the fish remaining. Brown blood disease disrupts oxygen transport in the cells of fish.
o Our Activities
Every day, we clear land for things we need, like landfills for our garbage, trees for our paper products, or space for our farms and cattle ranches.
We mine land for minerals we need and use oil drills to find gas for our cars. All these things have become necessities in our lives, but if we keep taking from our
environment without giving back, it will not sustain us.
• Sustainability Practices for Environmental Protection o Sustainability refers to the practices, services, and guidelines we develop to protect the
environment from our activities. o A sustainable practice can be any action that reduces environmental pollution and protects
Earth's biodiversity. On a local level, there are regulations that control the amount of land used for new
construction. When wildlife managers enforce hunting and fishing laws, they ensure the amount
of animals removed from an ecosystem does not disrupt the carrying capacity of any one population
At state and national levels, sustainable practices include the protection of parks and conservation areas, regulations for logging, and guidelines for best ranching
and farming practices Services meant to educate and inform help with sustainability, too.
ANSWER:
Part 4: Practice Question Answers
Salt water is an abundant resource but unusable for irrigation and drinking. As demands on freshwater sources increase, the use of desalination processes to remove salt from ocean water is increasing. A concern of desalination water is the large amounts of
recovered salts that are returned to the ocean. Which of the following describes the most likely impact of desalination on the surrounding ocean environment?
A. Methane gas would pollute the ocean environment as shoreline organisms begin to die and decay.
B. Alternation in ocean salt levels would cause loss of species and unbalanced
populations in marine food webs. C. Nonrenewable resources in the ocean environment would become depleted and
upset the ecosystem’s balance.
D. Increased levels of salts and minerals in the ocean would result in overpopulation of marine bivalves due to strengthened shells.
ANSWERS to Questions in the Hand-‐Out: 1. A. It becomes inactive
2. B. Carbon dioxide and water released by cellular respiration are used in photosynthesis. 3. C. Water exhibits cohesive behavior. 4. B. It shows possible common ancestry between organisms.
5. B. Limited food resources 6. C. The pythons could prey on native organisms and cause native populations to decline. 7. D. There is less available energy in the fourth trophic level because of the loss of energy
through metabolism in each of the lower trophic levels. 8. B. Alternation in ocean salt levels would cause loss of species and unbalanced populations in
marine food webs.
