1. MCAS Review
2012

2. Chemistry of Life

3. Define Organic
Compounds that contain carbon
atoms that are covalently bonded to
other elements, typically
hydrogen, oxygen, and other carbon
atoms
C-H-O

4. All living things are made up of 6
essential elements: SPONCH
Name the 6 elements of life:
 Sulfur
 Phosphorus
 Oxygen
 Nitrogen
 Carbon
 Hydrogen

5. Elements join together by
chemical bonds to form
compounds. Name the 3 types of
chemical bonds
 Covalent Bonds
 Ionic Bonds
 Hydrogen Bonds

6. There are 4 major categories of
organic molecules that are made
up of the SPONCH elements.
 Lipids
 Carbohydrates
 Proteins
 Nucleic Acids

7. Lipids
Elements: Carbon, Hydrogen, Oxygen
Structure: 3 fatty acid chains linked by a
glycerol backbone
Function: Building blocks of the cell
membrane, energy storing
molecules
Examples: Steroids like cholesterol & fats

8. Carbohydrates
Elements: Carbon, Hydrogen, Oxygen
Structure: Monosaccharides bonded
together in long chains (poly)
Function: Key source of energy!
Examples: Sugar and starch

9. Proteins
Elements: Carbon, Hydrogen, Oxygen, &
Nitrogen
Structure: Amino acids bonded in long
chains that coil around each
other into specific shapes
Function: Enzymes (speed up
reactions), structural
(hair, muscle, skin, etc), antibodies
(protect body)
Examples: Enzymes, collagen, antibodies

10. Nucleic Acids
Elements: Carbon, Hydrogen, Oxygen, Nitr
ogen & Phosphorus
Structure: Long chain of nucleotides
bonded together
Function: DNA (store genetic info), and
RNA (aid in building proteins)
Examples: DNA, RNA

11. Define Chemical Reaction:
 The process during which chemical bonds
between atoms are broken and new ones
are formed, producing one or more
different substances
AB + CD AC +BD

12. Write an example of a chemical
reaction and label the reactants
and products:
NaCl Na+ + Cl-
Reactant Products

13. Define Activation Energy
 The energy needed to start a chemical
reaction

14. Define Enzyme:
 Proteins that increase the speed of a
chemical reaction

15. Any factors that affect the shape
of an enzyme affect the enzyme’s
activity.
 What effect does pH and temperature
have on an enzyme’s function?
 pH and temp must be within an optimal
range for an enzyme to do its job
 If pH and/or temp are not in the proper
range then the enzyme may change shape
or become inactive

16. Cell Biology

17. Draw a Plant Cell

18. Draw an Animal Cell

19. Complete the Table:
Cell Part Function (job) Plant/Animal/
Both
Plasma Encloses the cell & separates Both
Membrane the cytoplasm from its
surroundings, regulates what
enters & leaves the cell
Nuclear Separates the nucleus from Both
Envelope the cytoplasm
Nucleus Stores DNA and makes mRNA Both
Nucleolus Located inside the nucleus, Both
mRNA is made here

20. Complete the Table:
Cell Part Function (job) Plant/Animal/
Both
Cytoplasm Interior part of the cell made Both
up of fluid that cushions all
organelles
Mitochondria Provide energy to the cell Both
Endoplasmic Process & modify proteins Both
reticulum that were made in the
nucleolus
Golgi Package proteins into vesicles Both
apparatus for export throughout the cell

21. Complete the Table:
Cell Part Function (job) Plant/Animal/
Both
Lysosome Contain digestive enzymes to Both
clean up the cell
Ribosome Aid in protein synthesis Both
Vacuole Help digestion of materials, Plant
store nutrients & keep cell
pressure
Cell Wall Support & maintain shape, Plant
protect cell from damage,
connect to nearby cells

22. Complete the Table:
Cell Part Function (job) Plant/Animal/
Both
Chloroplast Use light energy to make Plant
food (carbohydrates) through
photosynthesis
Cytoskeleton Help to maintain cell shape & Both
aids in movement of
materials in the cell
Centriole Help the formation of the Animal
spindle to move
chromosomes during mitosis

23. Prokaryote vs. Eukaryote
Prokaryote Eukaryote
 True nucleus
 No nucleus
 Organelles
 No organelles
 Reproduce either
 Reproduce asexually sexually or asexually
 Small  Larger
 Example: bacteria  Example: plant, animal,
protist, fungi cells

24. Draw the structure of the cell
membrane:
What is it called?
Phospholipid bilayer
Image source: library.thinkquest.org

25. Diffusion, Osmosis, & Facilitated
Diffusion
 Diffusion – Passive transport across a membrane from
an area of high concentration to low
concentration (downstream)
**Does not require energy
 Osmosis – Diffusion of Water
**Does not require energy
 Facilitated Diffusion -
Passive transport across a membrane from
an area of high concentration to low
concentration that requires carrier proteins
**Does not require energy

26. What are the 6 Kingdoms of Life?
 Eubacteria
 Archaebacteria
 Protista
 Fungi
 Plants
 Animals

27. Identify the formulas:
Photosynthesis
 6H20 + 6CO2 -> C6H12O6 + 6O2
Cellular Respiration
 C6H12O6 + 6O2 -> 6H20 + 6CO2 + energy

28. Define Photosynthesis
 The process that captures the sunlight’s
energy in the chloroplast of plant cells and
converts it to glucose (sugar), the food for
life

29. Define Cellular Respiration
 The process that breaks down glucose to
make energy for the cells to use

30. How are Photosynthesis &
Cellular Respiration related?
 They are opposites!
 One makes sugar (photosynthesis)
 One breaks sugar (respiration)

31. Humans need oxygen to be able
to perform cellular respiration
and gain ATP energy.
 What would happen to the oxygen levels
on Earth if photosynthesis stopped?
 Oxygen

32. What happens when a phosphate
group is removed from ATP?
 Energy is released for the cell to use!

33. Compare the energy levels of
ATP, ADP, and AMP to the energy
levels of a battery
 ATP (Adenosine Triphosphate) is like a
fully charged battery with 3 phosphates
 ADP (Adenosine Diphosphate) is like a
partially charged battery with 2
phosphates
 AMP (Adenosine Monophosphate) is like a
dead battery with only 1 phosphate

34. Draw and label the phases of the
cell cycle:
What is the function
of the cell cycle?
 To successfully
make new cells for
growth of the
organisms or
replacement of
dead or damaged
cells

35. Compare and contrast mitosis
and meiosis

36. Describe fertilization using
haploid, gamete, diploid, and
zygote

37. Genetics

38. What is DNA?
 Deoxyribonucleic acid
 The material that stores the information
that determines an organism’s
characteristics (traits)

39. Draw and Label a Nucleotide

40. How do nucleotides form the
structure of DNA?
 Nucleotides link
together to form a
chain
 Corresponding
nucleotides match-
up according to the
base-pairing rules
to form the second
chain

41. Draw a molecule of DNA
Hydrogen bonds
Sugar/Phosphate
backbone
Nucleotide
Nitrogen bases

42. What is a double helix?
 2 strands of
nucleotides
attached by
hydrogen bonds
in the middle and
twisted together

43. Base-pairing Rules:
Adenine – Thymine
Guanine - Cytosine

44. What is the relationship between
Gene and DNA?
 Genes are sections of DNA that code for
proteins
 The rest of the DNA codes for nothing!

45. 3 Steps of DNA Replication:
1. DNA helicase unwinds the double helix by
breaking the hydrogen bonds, forming
the replication fork
2. DNA polymerase adds complementary
nucleotides to the separated DNA strands
3. DNA polymerase continues until it
reaches the end of the molecule, forming
2 identical DNA molecules

46. Gene expression is the process of
turning the genes in the DNA into
a phenotype that can be seen
Draw and label
the 2 phases of
gene
expression, an
d where they
happen in the
cell

47. End Products
Replication Transcription Translation
Start DNA DNA RNA
End DNA RNA Protein

48. Types of DNA Mutations:

49. What will happen if there is a
mutation in a gamete?
 Gametes are egg and sperm cells
 A mutation would result in a genetic
disorder or failure to fertilize (no zygote)

50. Two parents are heterozygous for
brown eyes
 Bb x Bb
B b
Genotype Ratio:
B BB Bb 1BB:2Bb:1bb
b Bb bb
Phenotype Ratio:
3 Brown:1 Blue
What Percent of the Offspring have Blue Eyes?
25%

51. Why do men experience male-
pattern baldness more than
women?
 The trait is sex-linked
 Men only have one X chromosome, so
whatever allele they get for hair, whether
it is the dominant normal or the recessive
allele that causes baldness, it will show.
 Men have XY and women have XX

52. Using Mendel’s laws of
segregation and independent
assortment, explain why not all
tall people have brown hair.
 The law of segregation says that during
meiosis the alleles separate independently
during Metaphase II of meiosis
 The law of independent assortment says
that homologous chromosomes separate
independently during Metaphase I of
meiosis
 The two traits are chosen randomly

53. Describe an example for each of
the following:
Codominance – Polygenic traits -
Both forms of the trait are Several genes control one
displayed – dalmation dog trait – skin color or hair
with black spots color
Incomplete dominance – Multiple alleles -
Neither allele for the trait More than 2 alleles for one
is dominant – white flower trait – Blood types
X red flower = pink! A, B, AB, O

54. Anatomy & Physiology

55. Describe the 4 levels of structural
organization in the human body
 Cells
 Tissues
 Organs
 Organ Systems

56. Digestive System
Function Path of Food (all Important
major organs) Digestive
Enzymes
Breaks down and Mouth – pharynx – Amylase – in
absorbs nutrients epiglottis – saliva, breaks
from food; Esophagus – down sugar
removes waste; stomach – small
maintains water intestine – large Pepsin – in
balance intestine – rectum stomach, breaks
– anus down protein
Lipase – in
pancreas, breaks
down fat

57. Circulatory System
Function Path of Blood (all major
organs)
Transports nutrients, Capillary drops off
wastes, hormones, and nutrients to cell & picks up
gases waste – venule – vein –
right atrium – right
ventricle – pulmonary
artery – capillaries (lungs)
– pulmonary vein – left
atrium – right atrium –
aorta – artery – arteriole -
capillary

58. Excretory System
Function of Kidneys Function of Liver
Regulate the amount of Secretes bile which helps
water and salts in the break down fats and
blood absorb vitamins; regulates
sugar levels in blood

59. Respiratory System
Function Path of oxygen/carbon
dioxide (all major
organs)
Move air into and out of Mouth/nose – pharynx –
lungs; controls gas epiglottis – larynx –
exchange between blood trachea – bronchi –
and lungs bronchioles – alveoli –
bronchioles – bronchi –
trachea – larynx –
epiglottis – pharynx –
mouth/nose

60. Nervous System
Function Basic Unit – The Major
Neuron (How it Components
Works)
Regulates Neuron is made up Peripheral NS –
behavior; of dendrites that sensory & motor
maintains receive an neurons
homeostasis; electrical signal
regulates other which is then Central NS – brain
organ systems; carried to the cell & spinal chord
controls sensory body which is then
and motor carried through the
functions axon and is then
passed on to the
next neurons
dendrites

61. Muscular/Skeletal System
Function of Muscles 2 functions of bones
Help in movement of Provide shape and support
bones; contraction of heart to the body
and other organs Produce blood cells and
platelets in the marrow of
the bone

62. 3 types of muscle tissue
 Skeletal – muscles that move bones
 Smooth – involuntarily controlled; the
muscles that cause the stomach to
contract
 Cardiac – involuntarily controlled; is the
muscle that makes up the heart

63. 2 Types of Connective Tissue
 Ligament – attaches bone to bone
 Tendon – attaches muscle to bone

64. Define homeostasis
 The process of maintaining internal
stability within an organism

65. Explain how body temp is
maintained
 When it is cold out, the sensory neurons
(nervous system) send a signal to the spinal
cord then the brain
 The brain interprets the signal and sends a
message to the motor neurons
 The motor neurons trigger the muscles in
your body to contract/relax over and over,
which causes the bones to move
 This increases warmth in the body
 The heart also beats faster sending warm
blood more quickly throughout the body to
increase warmth

66. Evolution & Biodiversity

67. What is Evolution by Natural
Selection?
 Evolution is the change of a species over time
 This happens due to some kind of change in
the environment of an organism. It must
adapt or die
 If there is a mutation or trait that is
advantageous, it will be selected for (natural
selection)
 Organisms with the advantageous trait are
picked as mates and reproduce more
successfully, passing on the good genes
 Over time, the build-up of differences is called
evolution

68. Example:

69. Evidence for Evolution
Fossil Comparative Anatomy Genetic &
Record Homologous Vestigial molecular
Structures Structures similarities
Bones from The forearm Whale used Gorilla and
Lucy show a of penguin, to be a 4- human have
relationship human, legged an almost
between apes lizard, and animal on identical
and humans bats all have land and then hemoglobin
the same moved into protein in the
bones the sea and blood
evolved so
that the
pelvis and
legs have lost
their function

70. Speciation
 Mutation – elephant with NO tusks
 Reproductive Isolation – does not get hunted by
poachers and lives freely
 Natural Selection – live longer since they are not
hunted and are selected by other elephants
 Divergence – over time if populations stay
separated they may continually adapt and develop
more and more genetic differences
 New Species – if the 2 populations become so
genetically different that they no longer breed
successfully, they are considered 2 species

71. Define Species:
 The basic classification of living things

72. What characteristics are
organisms classified (or grouped)
by?
 Form and structure
 Behavior
 Molecular similarities

73. 8 Levels of Classification
 Domain
 Kingdom
 Phylum
 Class
 Order
 Family
 Genus
 Species

74. Binomial Nomenclature Rules:
 The first word is the Genus name and is
capitalized
 The second word is the species and is
lowercase
Humans = Homo sapiens

75. Define Biodiversity
 The variety of organisms, their genetic
differences, and the communities and
ecosystems in which they occur

76. How does evolution affect
biodiversity?
 Evolution by natural selection offers a
means by which organisms can become
more and more different over time to a
point where they become new species.
 Every living thing experiences evolution at
some speed
 The large biodiversity of life on Earth can
be attributed to the process of evolution

77. Ecology

78. What is Ecology?
 The study of interaction of living
organisms with one another and with their
physical environment

79. What are the components of an
ecosystem?
 Biotic factors (living) – plants, animals,
bacteria, fungi
 Abiotic factors (non-living) – soil, water,
weather, climate

80. Define Community
 All the living things in one ecosystem

81. Flow of energy
 Energy begins with the producers who take
the sun’s energy and turn it into food
 Primary consumers (herbivores) obtain their
energy by eating the producers
 Energy moves to the secondary consumers
(omnivores/carnivores) who obtain their
energy by eating the herbivores
 Lastly, when all organisms die, decomposers
obtain their energy and recycle it back into
the ecosystem

82. What does a food chain show?
 The path of energy flow in a specific
ecosystem
 Grass -> Rabbit -> Fox -> Wolf

83. How do food chains relate to food
webs?
 A food web is made up of many
interconnected food chains

84. Why are energy pyramids usually
no more than 4 trophic levels?
 As you go up the trophic levels in an
energy pyramid, energy is lost as heat
from the organisms that are not eaten
(die)
 Once you reach the top there is very little
energy available

85. Decomposers
Decomposers belong
anywhere outside the
pyramid. This is
because of their
niche. Decomposers
niche in an
ecosystem is to
obtain energy from
any dead organism
and then to recycle
the nutrients back
into the ecosystem

86. Water Cycle
 Water starts in the
nonliving as vapor in
the atmosphere
(clouds) then falls as
rain, goes into soil, is
taken up by the roots of
plants (now part of the
living) and then
transpired back into the
atmosphere

87. Carbon Cycle
Carbon in form of
carbon dioxide
(CO2)
Cellular Respiration Photosynthesis
Carbon in form of
food and living
things

88. Nitrogen Cycle
Nitrogen in the
non-usable form of
nitrogen gas
Denitrifying Nitrogen-fixing
bacteria bacteria
Nitrogen in the
usable form of
nitrates and
ammonia

89. Biological Communities
Commensalism Competition
Interaction between 2 When 2 organisms use the
organisms where 1 benefits same resources and there is
and the other is neither a struggle to obtain the
helped nor harmed resources
Parasitism Mutualism
Interaction between 2 Interaction between 2
organisms where 1 benefits organisms where both
and the other is harmed benefit
Predator/Prey
Interaction between 2 organisms where the predator needs
to hunt and kill the prey for food/energy in order to survive

90. Define Population
 A group of organisms of the same species
living in one area

91. Factors that affect population size
and biodiversity:
 Climate change
 Loss of resources
 Changes in symbiotic relationships
 Pollution due to human activity

92. Good Luck on the MCAS Biology Exam!
You can do it!