Fall 2015 Semester Exam Review Answer Key
LAB SAFETY
1. Review lab safety rules
SUPPORTING LIFE
2. List the characteristics that enable life to exist on Earth. Temperature/Proximity to the Sun,
Presence of Liquid Water, Composition of Atmosphere, Energy Source, Nutrients
3. What does it mean for a planet to be in a habitable zone? A habitable planet has characteristics
that are just right for allowing life to exist (temperature/proximity to sun, liquid water, composition of
atmosphere, etc.). Earth is the only known planet at this time.
4. Why is the proximity to the sun important to life? Because of its proximity (distance) from the sun,
Earth has a temperature range of 0°C to100°C, which allows life to exist, not too hot and not too cold.
5. Explain what gasses are included in our atmosphere and why they are needed. Nitrogen, Oxygen,
Argon, & Carbon Dioxide (NOArCo2). The Earth’s atmosphere thickness traps heat. The Ozone
layer protects Earth from the Sun’s harmful UV radiation.
6. What is gravity? How does it affect objects in the Solar System? Astronauts experience a feeling
of weightlessness in space (Microgravity). Larger objects have more gravitational pull than smaller
objects (Sun holds the Earth and planets in orbit, the Earth holds the moon in orbit)
7. What accommodations for life does a space suit help with? What is the most important? It
protects astronauts from:
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Lack of oxygen and severe temperatures that exist in space
Debris flying through space
Drifting off into space by tethers attached to rings on the suit
Helmet protects against harmful UV rays, O2 to breathe, communication to shuttle & Earth
Oxygen is most important
8. List 5 accommodations needed for manned space flight inside the space shuttle or space station?
 Exercise equipment to keep muscles and bones strong in microgravity
 Freeze-dried food and liquids in bags
 Special suction toilets
 Water purification system
 Sleeping with Velcro attached to the wall
8. What is a microhabitat? Give 5 examples. A very small specialized space with food, water and shelter
for organisms to survive and interact with biotic and abiotic factors. Ex’s: clump of grass, garden, flowerbed,
under a large rock, inside a hollow log
10. Define abiotic and biotic factors. Identify examples of each. Abiotic – nonliving or never living
Ex’s: sunlight, temperature, rocks, air, water, soil (S.T.R.A.W.S.)/ Biotic – living or once living Ex.’s:
animals, plants, people, dead trees, decaying animals or plants
ECOSYSTEMS
11. Briefly describe the climate, plants, and animals of each biome around the world.
 Tundra – arctic, extreme cold/snow/ice, few plants, lichen, shrubs, caribou, artic fox, polar bear
 Taiga/Coniferous Forest – cold winters/snow, evergreen trees, chipmunks, moose, bears
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Deciduous Forest – 4 distinct seasons, maple, oak trees (leaves change color), deer, rabbits
Tropical Rainforest – hot, humid, near equator, many plants, trees, snakes, birds, insects
Grasslands/Savanna – hot, dry, prairie grasses, few trees, giraffe, zebras, lions/buffalo, bears
Desert – extremely hot, dry, cold at night, few plants, cactus, snakes, lizards, scavenger birds
Marine/Salt Water – oceans, warm shallow, cold deep, kelp, plankton, fish, whales, sharks
Fresh Water – rivers, lakes, plankton, algae, large fish, crocodiles, hippos, large snakes
12. What is biodiversity? Which biome contains the most biodiversity? Amount of living things in a
biome, how many plants and animals there are, and how well it can last/sustain itself through change;
tropical rainforest and marine/salt water have most biodiversity
13. How does biodiversity lead to the sustainability of an ecosystem or biome? As biodiversity
increases, sustainability also increases. The more diverse (more living things), the more stable a
biome is. The more plants and animals there are, the more food choices are available.
14. What is a food chain? What is a food web? Draw an example of each using scientific words
(producer, consumer, etc. and examples (plants, animals, etc.) Food Chain – a group of
organisms in an ecosystem that are linked together through the transfer of energy (show what they
eat) Food Web - A combination of food chains that depend on each other.
Sun (Radiant Energy)
sun
Producer
(Plants)
shrubs, acorns
Primary Consumer
(Herbivores)
deer, squirrel
Tertiary/ Quaternary Consumer
(Carnivores, Scavengers)
bald eagle, bear
Secondary Consumer
(Omnivore, Carnivores)
fox, coyote
Decomposer
(Breaks down dead matter, becomes nutrients)
fungus, mushrooms, bacteria
Decomposer
.1%
1%
10%
100%
Heterotrophs
Autotroph
15. Draw an energy pyramid with the following: producer, primary consumer, secondary consumer,
tertiary consumer, decomposer, autotroph, & heterotroph. Include the 10% rule of how energy flows.
Which level has the most energy available?
16. Explain the process of decay of biomass and compost seen in a compost bin. What is released
as decomposition takes place? After a living organism dies, decomposers feed on and break down
the dead plants and animals. They make nutrients that were stored in biomass available to other
living things. The most common decomposers are earthworms, bacteria, and fungi. Nitrogen, CO2, &
heat are released into the soil and atmosphere.
17. Why do scientists use a dichotomous key? How do you use one? Dichotomous Key – tool used
by scientists to classify organisms, based on traits and structures of the organisms, uses a series of
go to instructions to follow, 2 choices for each characteristic (yes or no) to follow to next step
18. What is the difference between organic and inorganic compounds?
Inorganic Compounds (Molecules): Usually don’t have C (Carbon), come from earth, (STRAWS),
Simple Molecules/Compounds Ex.’s: H2O, CO2, NaCl
Organic Compounds (Molecules): Always have C (Carbon), H (Hydrogen), most times O (Oxygen),
sometimes N (Nitrogen), P (Phosphorus), S (Sulfur) Ex.’s: Glucose (C6H12O6), Fatty Acids
(C18H54O3) C.H.O.N.P.S. Cats Hate Obnoxious Noisy Poodles, Seriously!
19. List the types of energy. What is energy transformation? Give 5 examples.
R - Radiant (light from sun), E – Electrical (electrical current), C – Chemical (atoms bonded) –
Nuclear, T – Thermal (heat), M - Mechanical (movement), Potential – stored, Kinetic – in motion;
Energy transformation – when energy changes from one form to another, Ex’s:
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Radiant energy from the sun changes to chemical energy in plants (photosynthesis).
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When animals (& you) eat, chemical energy is transformed into mechanical energy
(movement).
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When you plug in an appliance, electrical energy changes to thermal, light, mechanical, etc.
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Energy in a flashlight battery changes from chemical energy to light energy.
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Gasoline in a car changes chemical energy into mechanical energy as the car moves.
DIVERSITY
20. Who is Charles Darwin? What did he study? Scientist who went to Galapagos Islands to study
finches. Saw the birds’ beaks were different sizes, shapes due to environment, type of food available
21. What is natural selection? Give an example. Natural Selection – organisms with traits best suited
to their environment are most likely to survive and reproduce. (Survival of the fittest based on
competition). Birds with efficient beaks, brown moths on dark trees, giraffes with longer necks
22. Define: migration, hibernation, & camouflage. Give examples of animals that do each behavior.
Migration – Instinctive movement of a group of animals to find more food, reach a better climate or
reproduce Ex’s: birds, butterflies, wildebeests, buffalo, fish, whales
Hibernation - State of dormancy with lowered body temperature & slowed metabolism Ex’s:
Rodents, marsupials (kangaroos, koalas), fish, snakes, frogs, bats, & bears
Camouflage - Ability to blend in with your environment Ex.’s: zebras, cheetahs, penguins, whales,
octopus
23. What is selective breading? Give examples of it in plants and animals. Selective breeding –
deliberate breeding of plants or animals for desired traits. Larger fruits or vegetables, crops that grow
better in the cold, cows that give more milk, chickens that lay more eggs, dogs with mixed breeds
ECOLOGICAL IMPACTS
24. Define weathering: Give examples of physical (mechanical) weathering and chemical weathering.
Weathering - The breaking down of rocks into smaller pieces called sediment,
Physical (mechanical) -Water (rain, rivers, oceans), Wind (carrying sand & sediment), Ice (freezes &
expands in cracks of rocks), Plants (roots grow & get larger in cracks of rocks)
Chemical - Oxidation (Iron Oxide = Rust, dissolves rocks), Acid Rain (factory and car pollution mixes
with water in atmosphere and falls as rain or snow), Carbonic Acid (dissolves calcium in caves), Plant
Acid (lichen & algae)
25. Define: erosion and deposition. Give examples of each. Erosion - weathered rock & sediment
is carried away Ex.’s Moving Water (Rain, Rivers, Waterfalls, Oceans), Wind, Ice (glaciers), gravity
Deposition - sediment relocated, dropped (deposited) in new place Ex’s: valleys, canyons, beaches,
deltas, rock formations, sand dunes, U-shaped valleys, moves boulders, mudslides, sinkholes
26. What is ecological succession? Process of an ecological community gradually changing over time
27. Describe the causes and the steps of Primary Succession and Secondary Succession. Primary
Succession – Causes: volcanic eruptions, glacial recession, sand dunes/ Steps: 1. Colonizing species
(moss, lichen), 2. Pioneer species (grasses, ferns), 3. Weeds & shrubs, 4. Young forest with small
trees, 5. Climax community with mature trees, lots of animals, stable biome (biodiversity)
Secondary Succession – Causes: Natural Disaster – earthquake, tornado, forest fire, hurricane,
Human disturbance – Cutting down forests (deforestation), clearing land for planting crops/ Steps:
1. Soil and seeds already in place in nutrient rich soil, 2. Grasses, wildflowers, shrubs return & new
species arrive, 3. Fast growing trees shade, protect slower trees, 4. New climax community forms
28. What are the differences between primary & secondary succession? Primary: Nothing was there
before; Little or no soil; Takes hundreds to thousands of years to reach climax community
Secondary: Happens after a disturbance of an established ecosystem; Soil is already in place, gets
more nutrients after disaster; Takes about 20-50 years to reach climax community again
29. Define: eco-region. Draw and label the Texas Eco-Regions. List natural disasters that affect
each area. Large area of land that has a distinct group of plants, animals, and other species
30. Define: watershed. Draw a picture of a watershed. Area of land that drains runoff into a
particular stream, lake, or other body of water (impermeable rocks can have flash floods)
31. Draw and label a diagram of groundwater. Study the definitions of each term in the picture.