Biology EOC Review

BENCHMARK SC.912. L.14.1

The cell theory is a widely accepted explanation of the relationship of cells and living organisms
composed of three parts:

1. All organisms are made of one or more cells.

2. Cells are the basic unit of structure and function in organisms.
3. Cells come from pre-existing cells.

The cell theory came to be thanks to the contribution of very important scientists:

1. Robert Hooke: he discovered and named cells. He observed a piece of cork using a coarse,
compound microscope that allowed him to see cells, which reminded him of the place where
monks lived, therefore naming them cells.
2. Van Leeuwenhoek: he was the first one to observe living cells using a compound microscope.
3. Theodor Schwann: he concluded that all animals are made of cells.
4. Matthias Schleiden: concluded all plants are made of cells. In 1839, Schwann and Schleiden
suggested that cells are the smallest unit of life.
5. Rudolf Virchow: he concluded that all cells come from previous cells.
6. Redi and Pasteur: proved spontaneous generation (abiogenesis) to be wrong.

Question Answer: C

BENCHMARK SC.912. L.14.3

Prokaryotic Cells:
 No nucleus: has a circular DNA called plasmid that is found on the cytoplasm.
 Ribosome: protein synthesis.
 Cell membrane: is semi-permeable, which means it allows some substances to enter the cell,
while it stops others.
 Cytoplasm: liquid part.
 Flagellum: movement.
 Cell Wall: protection and shape. Cell Wall

Cell Membrane

Ribosomes Flagella

Cytoplasm

Plasmid
 Eukaryotic Cells:
 Lysosome: breaks down and recycles molecules in the cell.
 Mitochondria: site of cellular respiration, powerhouse of the cell.
 Golgi Apparatus: packages and distributes proteins in the cell.
 Ribosomes protein synthesis.
 Nucleus: contains instruction on how to make proteins (DNA).
 Nuclear Envelope: surround nucleus.
 Nucleolus: makes ribosomes.
 Cytoplasm: fluid part.
 Cell membrane: controls what enters and leaves the cell.
 Vacuole (bigger in plant cells): stores food and water.
 Centrioles (only animal cells): organizes cell division.
 Rough ER: modifies proteins.
 Smooth ER: lipid synthesis.
 Microfilament: cilia and flagellum, movement.\
 Chloroplasts (only plant cells): site of photosynthesis.
 Cell Wall (only plant and prokaryotes): shape and protection.

Rough ER Lysosome
Cell Wall
Nucleus
Smooth ER

Nucleolus
Ribosome
Rough ER
Nucleus

Centrioles

Mitochondria
Ribosome

Golgi Apparatus

Lysosome
Cell Membrane Chloroplasts Smooth ER

Cell Membrane
Cells In Different Types of Solutions
Solution is Isotonic

The concentration of solute is equal in both sides of the membrane; therefore, water will move equally
in and out of the cell, and the cell won’t shrink nor swell.

Solution is Hypertonic

The concentration of solute is higher outside of the cell membrane; therefore, water will move out of the
cell, and the cell will shrink.

Solution is Hypotonic

The concentration of solute is higher inside the cell membrane; therefore, water will move into the cell
and the cell will swell up and burst.

Question Answer: D

BENCHMARK SC.912. L.14.7

Plant Organs:
 Leaf: production of sugars through photosynthesis, contains stomata, which is an opening that is
controlled by guard cells and allows gas exchange for photosynthesis and transpiration.
 Stem: transportation system, hold the plant straight.
 Roots: absorption of water/nutrients.
 Flowers: reproductive organ for angiosperms. Contains male/female gametes, eggs/pollen.
 Cone: reproductive organ for gymnosperms.
 Fruit:

Plant Tissues
 Dermal: protection, made up of epidermis cells, and a waxy layer called cuticle that stops the
plant from losing too much water.
 Vascular: Transport.
- Xylem: takes water from the roots to the stem, to the leaves.
- Phloem: takes sugars from the leaves to the stem, to the roots.
 Ground: storage and production of sugars.
 Meristematic tissue (only stems and roots): contains undifferentiated cells that can transform
into other tissues.
- Apical Meristem: end of roots, primary growth, adds length.
- Vascular Cambium: living cells, makes phloem and xylem, secondary growth, adds width.

Plant Structures
 Anther: makes pollen.
 Filament: hold up another.
  Stamen: male part of flower made up of the anther and filament.
 Stigma: traps pollen grains.
 Style: hold up the stigma.
 Ovary: reproductive organ that contains the ovule, where gametes are found.
 Pistil: female part of the flower made up of the stigma, style, and ovary.
 Petals: attraction mechanism.
 Sepal: protects the plant before it flowers.
 Root hairs: more water absorption.
 Root cap: protects apical meristem and secretes a slippery substance that makes it easier for the
apical meristem to grow through the soil.
Stigma
Style

Petals Ovary
Filament

Anther Ovule

Question Answer: B Sepal

Parietal Lobe
BENCHMARK SC.912. L.14.26

Frontal Lobe

Occipital Lobe

Question Answer: B Cerebellum

Medulla Oblongota (makes

Temporal Lobe the brain stem along with
the pons)

Pons
BENCHMARK SC.912. L.14.36

Factors That Affect Blood Flow:

1- Disease
- Atherosclerosis: a buildup of cholesterol, fatty substances, calcium, and other substances
called plaque forms in vessels, which leads to narrowing (smaller diameter) therefore a
slower blood flow. If the plaque breaks, it creates a blood cloth that stops blood flow, or it
can travel to other parts of the body. Depending on where it occurs, it can cause a heart
attack or stroke. Even if the plaque stays in its place, it can cause issues by creating a poor
blood flow that can cause chest pains, shortness of breath, leg pain, and loss of oxygen to
the brain.
2- Blood Pressure
- Blood pressure is cause by the contraction of the ventricles of the heart and differences in
blood pressure are responsible for the blood flow from one location to another. Arteries
become less flexible.
3- Resistance
- If blood is excessively viscous, it causes increased resistance, leading to slower blood flow;
therefore, higher blood pressure. More resistance in a longer and thinner vessel. Less in a
shorter and thicker vessel.
4- Exercise
- It causes us to breathe in more oxygen and respire quickly, causing our heart to have to
pump the oxygenated blood around our body faster and take deoxygenated blood to the
lungs to get carbon dioxide out. It healthily increases blood flow.
5- Blood Volume
- Higher blood volume slows down blood pressure as more blood flows through vessels. It
slows down blood flow and increase blood pressure.

Question Answer: A

BENCHMARK SC.912. L.14.52

Immune System: protects the body from pathogens, like bacteria, viruses, parasite, cancer cells through
specific and nonspecific responses.

Nonspecific First Line Defenses

They work against any type of pathogen that enters the body.

 Skin: contains a chemical barrier.

 Mucous, Tears, Saliva: contain a lysozyme that breaks down bacteria cell walls.
 Hairs in nostrils: the ciliary escalator, the cilia and mucous clean out debris from our longs and
trachea.
Nonspecific Defense Second Line
 Inflammatory Response: pathogen stimulates mast cells to release histamine, which rushes
blood to the area and white cells come in, mainly phagocytes that swallow and destroy bacteria.
 Fever: the body releases chemicals that increase body temperature and slows/stops the growth
of bacteria.
 Interferons: proteins made by host cells stop/ slows down viral growth to buy time for a specific
response to act.

Specific Responses
They act on specific pathogens.

 White blood cells, like lymphocytes and leukocytes that originate in the bone marrow.
 Vaccines: the injections of a weakened or similar but less dangerous form of a pathogen that
triggers antibody formation, to produce immunity.
- Exposure to antigen, forms antibodies. Memory cells T and B are produced. Strengthens and
quickens immune responses to specific pathogens. Antibodies attach to antigens and tag for
destruction. Antigens are any substance that can cause an inflammatory response.
 Antivirals: are drugs that can treat people that have been infected by a virus. They can prevent
or limit infection when given before or shortly after exposure before illness occurs.
 Antibiotics: are medicines that interfere with the production of bacteria and are only useful for
treating bacterial infections. Inappropriate use of antibiotics can lead to antibiotic resistance, a
growing health concern.

Question Answer: A

BENCHMARK SC.912. L.15.1

Patterns Of Evolution:
Adaptive Radiation: a single species develops into multiple different species due to differences in their
environment.

Convergent Evolution: distantly related organisms share many similarities due to living in similar
environments.

Coevolution: species evolve in response to changes in one another.

Extinction- 5 mass extinctions on earth and only 1% survived.

Punctuated Evolution – patterns of long stable periods of change interrupted by brief period of rapid
change.

Gradualism – constant patterns of change.

Evidence That Supports Evolution:
Fossil Record

It provides:

- Change over time (Before and After)

- History of life on Earth.
- Evidence of different groups of organisms.
- Shows change over time in morphological features in organisms.

Geological Time Scale- represents evolutionary time in Eras, Periods, and time.

Vestigial Structures- structures found on modern-day organisms that no longer have a function.

- Example: pelvic bone on snakes.

Homologous Structures – structures that share same pattern of development, but not necessarily same
function.

- Example: human arm and horse leg.

Comparative Embryology – same pattern of embryonic development in vertebrates.

Observed Evolutionary Change – evolution is observed through time.

Molecular Biology – the genetic code is universal and read the same way in all organisms.

Biogeography – The study of where organisms live now and where they and their ancestors lived in the
past.

Contribution Of Scientists to the Development of the Theory of Evolution

1- Darwin: natural selection.
2- Malthus: big population causes shortages in water, food, and shelter.
3- Hutton and Lyell: the earth is millions of years old and the processes that change in earth in the
past are the same processes affecting Earth today.
Question Answer: B
BENCHMARK SC.912. L.15.6

Binomial Nomenclature: two-part naming system composed of Genus and Species.

- Example: homo: genus, sapiens: species.

Taxonomy- the classification of organisms.

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

Bacteria Archaea Eukarya

Eubacteria Archaebacteria Protista Fungi Plantae Animalia
Prokaryote Prokaryote Eukaryote Eukaryote Eukaryote Eukaryote
Unicellular Unicellular Unicellular Unicellular Multicellular Multicellular
and and
Multicellular Multicellula
r
Cell Wall with Cell wall Cell wall Cell wall Cell Wall No Cell
Peptidoglyca made of made of made of Wall,
n cellulose; chitin cellulose; Centrioles
some have have
chloroplasts chloroplasts
Autotroph or Autotroph or Autotroph Heterotroph Autotroph Heterotroph
Heterotroph Heterotroph or
Heterotroph

Question Answer: C
BENCHMARK SC.912. L.15.13

Conditions Necessary for Natural Selection To Occur

 More organisms are born than can survive. This allows organisms with the best adaptation to
survive and reproduce. Organisms with advantageous traits will be more likely to pass on those
traits to their offspring, while the organisms with less advantageous traits will be less likely to
reproduce.
 Organisms vary in their characteristics, even within their species. Natural selection requires
genetic variation within organisms. Individuals in a population must have different heritable
traits or characteristics.
 Variation is inherited. Traits that show variation must be heritable, meaning they can be passed
from parent to offspring. The traits that are advantageous in an environment need to be capable
of being inherited by offspring.
 Differences in reproduction and survival are due to variation among organisms. Not all
organism in a population that are born can survive. Natural selection occurs when certain traits
offer advantages to organisms, increasing their chances of survival and reproduction.

Question Answer: B

BENCHMARK SC.912. L.15.8

Oparin
Abiogenesis: life comes from non-living things.

Chemical Evolution: large complex compounds come from smaller simpler molecules (macromolecules).

Pasteur
Disproved Oparin’s idea of spontaneous generation and any naturalistic origin of life.

Margulis
Gave a primary explanation on the origin of mitochondria and chloroplasts.

Proposed that eukaryotic flagella and cilia derived from endosymbiotic spirochetes.

Sidney Fox
Explored the synthesis of amino acids from inorganic molecules, the synthesis of proteinous amino acids
and amino acids polymers called “proteinoids,” and thermal energy.

Fox created protocells, named “Microspheres” in his lab that had the characteristics of cells like a
membrane, and they can store and release energy.
Miller and Urey
Created an experiment recreating Erath’s early atmosphere from which they created 20 amino acids.

- Amino acids are the tools for life (first organic molecules).
- Amino acids are the “beginning of life.”

Question Answer: C

BENCHMARK SC.912. L.15.13

Gene and Variation (difference)

 All organisms have genes that are invisible.
 Invisible genes are the heterozygous form. (Hh) H is dominant and h is “invisible” (recessive).

Variation on the Gene Pool

 Gene pool consists of all the genes within a population.
 Relative frequency is the number of times an allele (gene) is seen in the gene pool.

Source of Genetic Variation

 Mutations.
 Genetic Recombination.
- Crossing Over.
- Independent Assortment.

Single Genes and Polygenic Traits

 Single gene is one trait.
 Polygenic traits are traits controlled by two or more genes.

Natural Selection on Single Traits

 Single gene population can lead to changes when the genes are not fit for adaptation which
causes the allele frequency to change.

Natural Selection on Polygenic traits are:

- Directional Selection.
- Stabilizing selection.
- Disruptive Selection.

Directional selection – the environment favors the extreme.

Stabilizing Selection – the environment favors the average, not the extreme.

Disruptive Selection – the environment favors both extremes.

Genetic Drift (Small Population)

- Founder Effect: By change, the minority of alleles of a population decide to leave the
population and colonize a new land. Then, the new place is made up mainly of the minority
alleles.
- Bottleneck Effect: Disease kills the members of a population that are the majority of alleles.
The minority of alleles are left to reproduce, and the population is now made of mostly of
the alleles that were not the majority.

The Process of Speciation – How Species Are Made

Behavioral Isolation – different behaviors or mating rituals.

Geographical Isolation – species are separated by a geographic barrier.

Temporal Isolation – species reproduce at different times.

Reproductive Isolation – species no longer produce fertile offspring and can no longer interbreed.

- Not same locations.

- Different habitats.
- Different ova reproductive cycles.
- Wrong sexual organs.

Question Answer: B

BENCHMARK SC.912. L.16.1

Mendel’s Law of Segregation

Alleles of the same trait will separate during gamete formation.

Mandel’s Law of Independent Assortment

Alleles of different traits will separate during gamete formation.

Sex Linked Diseases

- Hemophilia – no blood clotting.
- Color blindness – can’t distinguish between colors.
- Baldness.
- Duchenne muscular dystrophy – muscle loss.

Question Answer: B

A- I^B I^B
 B- I^A I^i
C- I^i I^i
D- I^A I^i
E- I^A I^B
F- I^i I^i
G- I^i I^i

2-

3-

4- A- Mr. Click has genotype I^i I^i.

B- Mrs. Click must have genotype I^A I^A.
C- B.
5- A- I^i I^i
B- I^A I^B
C- I^A I^i, I^B I^i
E- No.

BENCHMARK SC.912. L.16.13

  From 0-90 days is called an embryo.
 After 90 days, it’s called a fetus.
 Zygote- forms when egg meet sperm (fertilization).

Male Reproductive System

 Testicles: create sperm.
 Epididymis: stores and matures sperm.
 Vas Deferens: Tube sperm travels through. Leads to the urethra.
 Urethra: Leads outside the body.
 Prostate gland: secretes a fluid that nourishes and protects the sperm.
 Seminal Vesicle: secretes a fluid that nourishes and protects the sperm.
 Scrotum: sack that protects the testicles.
 Penis: organ leading to the outside of the male body.

Vas Deferens

Seminal Vesicle

Penis
Prostate Gland
Urethra Epididymis
Testicles

Scrotum

Female Reproductive System

 Vagina: leads outside the body, stages of development.
 Uterus: Baby development, implantation.
 Ovaries: Produces eggs.
 Oviduct (Fallopian Tube): site of fertilization.
 Cervix: connects uterus to vagina, birth canal.
 Fallopian Tube

Ovaries

Uterus
Cervix

Vagina

 Umbilical Cord: connects the baby and the placenta. Respiration, nourishment, and excretion.
 Placenta: connects baby and mom. Organ for respiration, nourishment, and excretion.
 Amniotic Sac: a fluid-filled sac that cushions and protects the baby.
 Amniotic fluid: protection and maintains temperature.

Fetal

Development During First Trimester

 Implantation: zygote fuses into the
uterus.

 All major system and organs begin to form.

gastrula: formation of three layers of cells.
 The neural tube, the digestive, and the heart circulatory system begin to form.
 The beginnings of the eyes and ears starts.
 Tiny limb buds appear.
 The heart is beating. Neurulation: formation of the nervous system.
 All major body systems continue to develop and function, including the circulatory, b=nervous,
digestive, and urinary systems by the end of 8 weeks.
 The embryo is taking on a human shape, although the head is larger in proportion to the rest of
the body.
 The mouth is developing tooth buds (which will become baby teeth)
 the eyes, nose, mouth, and ears are becoming more distinct.
 the arms and legs are clearly visible.
 the fingers and toes are still webbed but can be clearly distinguished.
 the main organs continue to develop, and you can hear the baby's heartbeat using an instrument
called a Doppler.
 the bones begin to develop, and the nose and jaws are rapidly developing.
 the embryo is in constant motion but cannot be felt by the mother.

Fetal Development During Second Trimester

 The fetus kicks, moves, and can turn from side to side.
 The eyes have been gradually moving to the front of the face and the ears have moved from the
neck to the sides of the head. The fetus can hear the mother's voice.
 A creamy white substance (called vernix caseosa, or simply vernix) begins to appear on the fetus
and helps to protect the thin fetal skin. Vernix is gradually absorbed by the skin, but some may
be seen on babies even after birth.
 The fetus is developing reflexes such as swallowing and sucking.
 The fetus can respond to certain stimuli.
 The placenta is fully developed.
 The brain will undergo its most important period of growth from the 5th month on.
 Fingernails have grown on the tips of the fingers and toes, and the fingers and toes are fully
separated.
 The fetus goes through cycles of sleep and wakefulness.
 Skin is wrinkly and red, covered with soft, downy hair (called lanugo).
 Hair is growing on the head of the fetus.
 Fat begins to form on the fetus.
 Eyelids are beginning to open, and the eyebrows and eyelashes are visible.
 Fingerprints and toeprints have formed.
 Rapid growth is continuing in fetal size and weight.

Fetal Development During Third Trimester

 The fetus can see and hear.
 The brain continues to develop.
 The bones of the skull remain soft to make it easier to pass through the birth canal.
  For many babies, the irises of the eyes are slate blue. The permanent eye color will not appear
until several days or weeks after birth.
 The fetus can suck its thumb and has the ability to cry.

Question Answer: B

BENCHMARK SC.912. L.16.17, 16.8, 16.14, 16.16

Mitosis
Mitosis produces two daughter cells that are identical to the parent cell. For somatic cells (body cells).
Maintains chromosomes number. No genetic diversity, asexual reproduction.

2n

Interphase
G1: Cell grows in size.

S: DNA Duplicates.

G2: Cell makes everything needed for cell division.

Prophase
 Chromosomes become visible.
 Centrioles move to opposite sides in the cell.
 Nuclear envelope breaks down.
 Spindle fibers form

Metaphase
 Chromosomes align in the center of the cell.

Anaphase
 Spindle fibers connect to centromeres and separate sister chromatids.

Telophase
Pro – Metaphase
 Interphase Prophase Metaphase  Chromosomes uncoil.
 Nuclear Envelope reforms.
 Spindle fiber disappear.

Cytokinesis
 Cell divides and two daughter
Anaphase Telophase
cells form.
 In animals, the cell pinches in.
 In plant, a cell plate forms which
becomes the cell wall and the
cell divides.

Cytokinesis

Meiosis
Produce gametes or sex cells. Daughter cells are not identical to parent cell. Produces 4 daughter cells
with half the chromosome number of the parent cell. Genetic diversity, sexual reproduction.

Interphase
G1: Cell grows in size.

S: DNA Duplicates.

G2: Cell makes everything needed for cell division.

Meiosis 1: Prophase 1
 Chromosomes become visible.
 Centrioles move to opposite sides in the cell.
 Nuclear envelope breaks down.
 Spindle fibers form
 Tetrad forms, which are pairs of homologous chromosomes.
 Crossing Over occurs where homologous chromosomes exchanges pieces of DNA.

Meiosis 1: Metaphase 1
  Homologous chromosomes align in the center of the cell.

Independent Assortment: random arrangement of chromosomes. Alleles of different genes separate

during gamete formation.

Meiosis 1: Anaphase 1
 Spindle fibers separate homologous chromosomes.

Meiosis 1: Telophase 1
 Nuclear Envelope reforms.
 Spindle fiber disappear.
 Chromosomes uncoil.

Meiosis 1: Cytokinesis 1
•Prophase
Cell divides
1 and two daughter cells form.
Metaphase 1
Meiosis 2: Prophase 2
Anaphase 1
 Chromosomes become visible.
 Centrioles move to opposite sides in the cell. Telophase 1
 Nuclear envelope breaks down.
 Spindle fibers form

Meiosis 2: Metaphase 2
 Single Chromosomes align in the center of the cell.

Meiosis 2: Anaphase 2
 Spindle fibers connect to centromeres and separate sister chromatids.

Meiosis 2: Telophase 2
 Chromosomes uncoil.
 Nuclear Envelope reforms.
 Spindle fiber disappear.

Meiosis 2: Cytokinesis 2
 Cell divides and four daughter cells form.

Prophase 2

Metaphase 2
Telophase 2 Anaphase 2
 Question Answer: C

Cytokinesis 2

Cancer: uncontrolled cell growth and abnormal cell division.

 Caused by gene mutations that may result from exposure to chemicals, carcinogens,
radiation, and other causes.

BENCHMARK SC.912. L.17.5

Aquatic Ecosystems are affected by:

 Water Depth.
 Temperature.
 Flow
-Moving water that brings in oxygen and nutrients.
 Dissolved nutrients.
 Distance from the shore.

 Photic zone- the region where sunlight penetrates through the water.

- Phytoplankton (photosynthetic algae) live here.

- They are eaten by zooplankton.

 Aphotic zone- region below the photic zone where photosynthesis cannot occur because
sunlight doesn’t reach.

- Primary producers = chemosynthetic autotrophs.

Different types of organisms exist within aquatic systems due to:

Chemistry:

 pH, Oxygen, Carbon Dioxide, Nitrogen, Phosphorus, salinity

Geography:

 depth, latitude, temperature, topography, proximity to land

Temperature

 Deeper = colder.
 Hotter near equator; colder near the poles.
 Currents carry warmer/cooler water to a given area.
Nutrients: aquatic organisms need:
 Oxygen.
 Nitrogen: source of food for algae.
 Potassium: weathering of rocks.
 Phosphorus: fertilizer.
 The type and availability vary in different bodies of water.
 The difference affects where organisms can live.

Seasonal Variations
 Temperature, precipitation

Climate change
 Changes in temperature of Earth
 Changes in clouds, wind, amount/pattern of precipitation.

Invasive species
 Loss of biodiversity

Ecological succession- a series of changes that occur to an ecosystem over time.

Primary Succession-succession that begins in an area that has no previous community.

 Occurs because volcanic eruption/glacier retreating.

 No soil/no plant life.
 Slow.

Pioneer species- the first species to colonize barren areas.

 They grow on barren rock/break down rock = soil

Secondary succession- occurs in an area that was only partially destroyed by natural disasters or human
activity.

 Occurs faster than primary succession.

 Soil remains so new vegetation can grow rapidly.

Natural disturbance
 Wildfire, hurricane.

Human disturbance
 Logging, farming.
Population Size is Determined by:
 Birth rate.
 Death Rate.
 Immigration Rate.
 Emigration Rate.

If death rate is higher than birth rate, the population size sill decrease.

If birth rate is higher that death rate, then the population size will increase.

If immigration rate is higher than emigration rate, then the population size will increase.

If emigration rate is higher than emigration rate, then the population size will decrease.

A population carrying capacity is determined by:

Limiting factors.

Density dependent
 Factors that depend on population density.
 Don’t affect small/scattered populations as much.
- Parasites and disease.
- Predators.

Competition
- Organisms compete for food, water, space, sunlight, and resources when
populations become overcrowded.

Overcrowding
– Causes fighting.

– Leads to stress.

– Leads to emigration.

– Causes females to neglect and kill offspring.

Density independent
 Factors that do not depend on population density.
- Bad weather.
- Natural disasters.

Loss Of Biodiversity is Due to:

 Invasive Species
- New species outcompete original species.
  Human Activity
- Changing habitats.
- Hunting.
- Introducing new species.
- Pollution.
- Climate change.
 Agriculture
- Loss of wild plant species = loss of genes for pest and disease resistance.
- Loss of useful medicine.
 Diverse ecosystems are important for soil, water, and air quality.
 The loss of species may make an ecosystem less valuable to people.

BENCHMARK SC.912. L.18.1

Enzymes are catalysts that speed up chemical reactions by lowering activation energy.

Enzymes are affected by pH and temperature.

Carbohydrates
 Function: short-term energy storage.
 Building Block: Monosaccharides.
 Made of carbon, hydrogen, and oxygen with a fixed ration of 1:2:1.
 Examples: sugars, cellulose, starches, glucose.
 Structure: often drawn as skeleton, in aqueous solutions they form ring.
Lipids
 Function: long-term storage of energy, insulation,
makes up cellular membrane.
 Phospholipid bilayer: hydrophilic head,
hydrophobic tails.
 Building Block: glycerol with three fatty acid tails.
 Examples: fats, oils, waxes, sterols.
 Made of carbon, hydrogen, and oxygen.

Nucleic Acids
 Function: Store and transmit genetic information.
 Building Block:
- Nucleotides: five-carbon sugar, phosphate group, nitrogenous bases.
 Made of carbon, hydrogen, nitrogen, oxygen, and phosphorus.
 Example: DNA, RNA, ATP.

Proteins
 Function: immune system, carriers, catalysts (enzymes), part of cell membrane, cell structures.
 Building Block:
- Amino Acids, r group, NH2, COOH.
 Example: enzymes.
 Made of carbon, hydrogen, oxygen, and nitrogen.
 Protein denaturation: protein unravels and loses its shape.
- Loss of function.
- Occurs because: Organic solvent, any chemical that disrupts its structure, pH, and
temperature.

Question Answer: A
BENCHMARK SC.912. L.18.12

Water is a polar molecule, meaning it has partial positive and negative molecules.

Properties of Water
Cohesion: water molecules stick to water molecules.

 Positive charges are attracted to negative charges.

Versatile Solvent

 Water is a good solvent due to its polarity.

 It dissolves many substances.

Expands when frozen.

 Water is less dense when it’s frozen.

 Surface ice insulated water below it.
 Cycling nutrients.

High Specific Heat

 It takes a lot to heat up and cool down water.

 Water moderates temperatures on earth.

Question Answer: C

BENCHMARK SC.912. L.18.9

The products of photosynthesis are the reactants of cellular respiration.

Photosynthesis
Reactants: energy, carbon dioxide, water.

Products: oxygen, glucose.

H2O + ENERGY + CO2 --- O2 + C6H12H6

Cellular Respiration
Reactants: Oxygen, Glucose.

Products: Carbon Dioxide, Water, ATP.

C6H12O6 + O2 ----- CO2 + H2O + ATP

Glycolysis: anaerobic, cytoplasm, 2 ATP molecules.

Citric Acid Cycle: aerobic, mitochondria, 2 ATP molecules.

Electron Transport Chain: aerobic, mitochondria, 32 ATP molecules.

ATP is a high energy molecule that releases energy when bonds between the third and fourth phosphate
group are broken.

It has a nitrogenous base, sugar, and three phosphate groups.

ATP is used for:

 Respiration.
 Photosynthesis.
 Metabolism.
 Muscle contraction.
 Cell Activity.
 Cell Movement.
 Fluorescent (light bugs).

Fermentation
Anaerobic- without oxygen.

 Alcoholic Fermentation
- Products: carbon dioxide, ATP, and alcohol.
 Lactic Acid Fermentation
- Products: carbon dioxide, ATP, lactic acid.

Question Answer: B