7th Science

Exam Review Key 2014

USE THE INFORMATION IN THIS PACKET TO CHECK YOUR ANSWERS. MAKE SURE YOU ALSO ATTEND TUTORIALS, STUDY YOUR NOTES, TEST REVIEWS, LABS, ETC.

EXAM SCHEDULE

1

Wednesday - 5/27

1st, 2nd, & 3rd Period Exams

Regular Release @ 3:15

Thursday – 5/28

4th & 5th Period Exams

Early Release @ 12:00

1

Friday – 5/29

6th & 8th Period Exams

Early Release @ 12:00

1

NO SECTIONS WILL BE ACCEPTED FOR “LATE CREDIT” AFTER 5/21.

THE KEY WILL BE POSTED ONLINE on Friday 5/22.

CHEMISTRY

1.  Matter: any material substance with Mass & Volume

2.  Physical Property: Can be observed using your senses (mass, color, shape, smell, volume, density, melting point, boiling point, and hardness)

3.  Chemical Property: Cannot be observed with senses- must be tested or reacted with something (ability to burn, ability to decompose (food), ability to rust, how it reacts with other substances)

4.  Physical Change: Do NOT CHANGE THE IDENTITY OF MATTER on a chemical level

a.  Give 3 examples: change in state, shape, color, size

5.  Chemical Change: Matter changes at the atomic level (atoms separate and recombine in different ways!) and NEW SUBSTANCES are created

a.  Give 3 examples: Rusting, Burning, Cooking

6.  Signs of a chemical change: Formation of a gas, formation of a precipitate (solid), change in temperature, change in color, energy produced

7.  Law of Conservation of Mass/Matter: Matter cannot be created or destroyed, only transformed/changed

8.  Atom: the smallest particle making up elements

9.  Element: pure substances that make up everything in the universe

10.  Molecule: 2 or more elements chemically combined to form a new substance with new properties

11.  Compound: 2 or more DIFFERENT elements chemically combined to form a new substance with new properties

a. Give an example of something that is a molecule, but not a compound: H2, O2, Au (gold)

b. Give an example of something that is a molecule and a compound: H2O, CO2

12.  Pure Substance: Something made up of only one type of atom

13.  Four Types of Organic Compounds:

a.  Carbohydrates

b.  Lipids

c.  Proteins

d.  Nucleic Acids (DNA & RNA)

*Also know how each main example is broken down by our bodies

*What element do all organic compounds contain? Carbon

14. Your digestive system must break down carbohydrates into Simple Sugars so your body can use them.

15. Acid: Something with a pH less than 7, sour, reacts with metals

16. Base: Something with a pH greater than 7, bitter, slippery

17. Neutral: Something with a pH of 7, does not react

18. pH: the measure of how acidic or basic a substance is

ECOLOGY 1

19.  Biome- large geographic area that shares similar vegetation and climate (temp & precip)

*Know general characteristics of the world’s major biomes- see notes

*be familiar with structural/behavioral characteristics needed to survive in different biomes

20.  Adaptation- a body structure or behavior that helps an organism survive

21.  Structural Adaptation- physical characteristics that help an organism survive

22.  Behavioral Adaptation- a behavior or activity that helps an organism survive

23.  Instinct- a pattern of behavior that requires no thinking- organisms know how to do this from birth

24.  Migration- an instinctive behavior where some animal populations more to a new place for a period of time

25.  Hibernation- an instinctive behavior where some animals spend winter in an inactive condition

26.  Learned behavior- a behavior that an animal learns through experience

27.  Mimicry- an adaptation where one species mimics another species (in looks or behaviors)

28.  Camouflage- an adaptation where an organism can blend in with its surroundings

29.  Natural Selection-gradual process where populations naturally change over time; some traits become more common and other traits become less common

30.  Selective Breeding- humans select specific traits to breed together to get a certain outcome

31.  A bird is born with a beak that is longer than the beak of other birds in the species. The

longer beak helps the bird catch more food, which makes it healthier than the other birds, this will live longer and breed more than the other birds. Is this an example of natural selection, or selective breeding?

This is natural selection, because the trait is beneficial it is more likely that the bird will survive. Because it is more likely to survive, it is more likely that its genes will get passed on and that trait may become more common. It’s natural selection because there is NO human involvement.

32.  A pet store is breeding two different types of dogs, hoping they will produce a combination of both of the dogs traits in their offspring. Is this an example of natural selection, or selective breeding?

This is selective breeding, because humans are controlling the breeding so that certain traits occur in the offspring. It’s not a natural process.

33.  Biotic - a living factor in an ecosystem

34.  Abiotic - a non-living factor in an ecosystem

35.  Symbiosis – a close relationship between 2 species (“symbiosis”= living together)

a.  Parasitism: (+/-) one organism benefits while the other organism (host) is harmed

b.  Mutualism: (+/+) both organisms benefit in this relationship

c.  Commensalism: (+/0) one organisms benefits, and the other organism isn’t hurt or helped

36.  Limiting factor - any factor that restricts the size of a population (space, resources, mates, natural disasters, disease, hunting, etc)

37.  Competition - organisms attempting to use the same resource at the same time

38.  Predation – one organism (consumer) captures and kills another organism (consumer) (this is NOT a type of symbiosis!)

39.  Niche – an organism’s specific role or job within its ecosystem that helps it survive

40.  Habitat – where an organism lives within its ecosystem

41.  Species – organisms of the same kind that can interbreed

42.  Population – organisms of the same species

43.  Community – all of the populations in an ecosystem

ECOLOGY 2

Define the following words:

44.  Stimulus- something that causes a response

45.  Response- a reaction brought about by a stimulus

46.  Internal Stimulus- stimulus that comes from inside the animal

47.  External Stimulus- stimulus that comes from outside the animal

48.  Phototropism- a plant’s growth in response to light

49.  Geotropism- response to earth's gravity, as in the growing of roots downward in the ground

50.  Producer - an organism that makes its own food (also known as autotroph)

51.  Decomposer - organism that breaks down and obtains energy from dead organic matter

52.  Consumer - an organism that obtains energy by feeding on other organisms (also known as heterotroph)

53.  Biomagnification – the process where toxins increase in concentration as they move up the food chain

54.  Give 2 examples each of internal and external stimulus & response:
Internal: hunger- eating; thirst- drinking

External: light- squint; temperature- put on jacket

55.  Explain the difference between the terms autotroph and heterotroph.

An autotroph is capable of making its own food/energy (a producer) while a heterotrophy has to go and consume food for energy (a consumer).

4

4

1. animal
not an animal / go to 2
go to 11
2. has wings
no wings / go to 3
go to 6
3. has feathers
no feathers / go to 4

Ochloerotatus taeniorhynchus

4. flies high
does not fly high / go to 5

Meleagris gallopavo

5. often yellow
not yellow / Serinus canaria
Haliaeetus leucocephalus
6. lives in water
lives on land / go to 9
go to 7
7. has fluffy fur
no fluffy fur / go to 8
Bos taurus
8. common pet
not a common pet /

Canis familiaris

Mephitis mephitis
9. has fins
no fins /

go to 10

Haematopus ostralegus
10. razor sharp teeth
pegged, pointy teeth /

Carcharodon carcharias

Tursiops truncates
11. green
not green /

go to 12

go to 13
12. grows tall
does not grow tall /

Pinus ponderosa

Rhus toxicodendron
13. can be poisonous
not poisonous /

Boletus edulis

Rosa sylvestris

56. Use the key on the right to identify the organisms below.

Common Name / Scientific Name
1. dog /

Canis familiaris

2. shark /

Carcharodon carcharias

3. rose / Rosa sylvestris
4. skunk / Mephitis mephitis
5. turkey / Meleagris gallopavo
6. dolphin / Tursiops truncates
7. eagle / Haliaeetus leucocephalus

57. Diagram a simple food chain (using any organisms) and label the following parts; producer, primary consumer, secondary consumer, tertiary consumer, and quaternary consumer.

Sun Producer Primary C Secondary C Tertiary C. Quaternary C

à àààà

58. What do the arrows in a food chain represent? Explain why the arrows on food chain point in a specific direction.

The arrows of a food chain indicate the direction in which the energy flows.

59. Describe the 10% rule and how it applies to food chains. Also, explain what happens to the other 90% of the available energy.

The 10% rule describes how much energy is transferred to each organisms in the food chain/web/pyramid. When a consumer eats the previous organism, it will use 90% of the energy for itself while 10% will be stored and available for the next consumer in line.

60. Using your food chain from #57, design and solve one 10% rule problem for your food web.

Sun Producer Primary C Secondary C Tertiary C. Quaternary C

à àààà

100,000j 10,000j 1,000j 100j 10j 1j

61. Write out the chemical equation for photosynthesis.

6CO2 + 6H2O + sunlight à 6O2 + C6H12O6

Carbon dioxide + water + sunlight à oxygen and glucose

62. What types of organisms can photosynthesize?

Plants (autotrophs) because they have chloroplasts with chlorophyll.

63. What type of energy transformation occurs during photosynthesis?

Solar energy from the sun is transformed in to potential energy (glucose).

1.  Pond Grass

2.  Grasshopper

3.  Shrimp

4.  Bass

5.  Heron

6.  Shrew

7.  Owl/Hawk

8.  Duck

9.  Songbird

10.  Sandpiper

64. In the above food web, identify a:

Producer: pond grass

Primary Consumer: grasshopper

Secondary Consumer: duck

Tertiary Consumer: owl/hawk

65. What organisms would potentially suffer if the grasshopper population greatly decreased due to harmful pesticides? How might this change impact the overall food web?

The populations of songbirds, ducks, mice, and shrews would greatly decrease. The shrews would decrease the most because they do not have any other source of energy besides the grasshoppers. If the shrews eventually die off, it would reduce the variety of energy sources for the hawk/owls and that in turn would throw off all biodiversity making the ecosystem much weaker and less likely to sustain itself.

66. What do the arrows represent (in a food chain/web)?

The transfer of energy from one organism to another along the food chain.

67. At which level in a food chain/web is there the greatest amount of available energy?

Producer will have the greatest amount of energy.

68. Explain the difference between a food web and a food chain.

•  Food webs are a simple transfer model of energy from sun to producer to primary consumer to secondary consumer to tertiary consumer.

•  Food chains are interconnected food chains

69. If you ate 3 big fish, which had each eaten 5 small fish, who had each had 10 insects, who had each had 25 plant pieces, how much methylmercury would be in you? Assume that each plant piece each has one drop of methylmercury.

3750 drops of methylmercury

ENVIRONMENTAL CHANGES

Know definitions and examples of the following words:

70. Weathering- the chemical and physical breakdown of rock

71. Erosion- the movement of sediment, or weathered rock, from one place to another

70.  Deposition- the placement of weather rock, or sediment, at a site other than its place of origin

71.  Condensation-process where water vapor collects in clouds (as the clouds cool the water vapor condenses into water drops).

72.  Precipitation- water falls to the earth from clouds- mainly as rain, but sometimes as snow, sleet or hail.

73.  Transpiration- the process by which plants lose water out of their leaves

74.  Evaporation- the process where heat energy from the sun causes bodies of water (puddles, lakes, rivers etc.) to change from liquid to a water vapor; vapor then rises into the air and collects in clouds.

75.  Watershed- an area of land from which all runoff drains/”sheds” to the same body of water.

76.  Aquifer- a layer of underground rock, or sediment, through which water can move easily.

77.  Runoff- water travels downhill and enters into rivers and lakes

78.  Water Table- the underground depth at which point the ground is totally saturated with water.

79.  Ground Water- flows underground as spring or underground rivers (stored in aquifer).

80.  Surface Water-water on the surface of the earth.

83. Describe the steps of ecological succession. Use the words climax community, pioneer species, and

biodiversity in your explanation. Ecological succession is a series of predictable changes that occur in a terrestrial community over time. In a place where soil is not present, primary succession would begin once the first organisms, or pioneer species, such as lichens arrive. Lichens do not need soil to live and would be able to thrive. As lichens decompose they add to the soil, which was created by rocks being broken down by weathering and erosion. Simple plants are able to live and grow in the soil, and soon more complex organisms and animals are able to survive leading to a climax community. This climax or stable community completes the process of succession; biodiversity has been achieved and a great variety of different organisms will remain and exist together, as long as the community is undisturbed.

84.  What is the difference between primary and secondary succession?

The difference between the two types of succession is the presence of soil in the area where the process will occur. Primary succession usually occurs in a place without soil (typically after a natural disaster), such as volcanoes landslides or floods. Primary succession is much slower because soil has to be created.Secondary succession usually occurs in an area where soil already exists. “Step 1” of primary succession is skipped and occurs much faster.