Biology

Cell membrane

Cytoplasm

Cell wall

Vacuole

Reptiles

Fish

Amphibians

Birds

They all breathe oxygen through lungs

They all move from place to place

They all require nutrition

They all have a heart

$Canis$ $latrans$

$Felis$ $catus$

$Lupus$ $lupus$

$Vulpes$ $vulpes$

Inside a membrane-bound nucleus

Stored within the mitochondria

As a circular loop of DNA free in the cytoplasm

Attached to the cell wall

The loss of water vapor from the leaves

The growth of roots toward a source of water

The absorption of minerals from the soil

The production of glucose in the chloroplasts

Excess water only

Undigested food remains

Toxic materials and waste products of metabolism

Substances that are harmful if eaten

Growth

Reproduction

Sensitivity

Nutrition

They belong to different genera but the same species.

They belong to the same genus but different species.

They belong to different families and different orders.

They can interbreed to produce fertile offspring in the wild.

All kingdoms have 80S ribosomes in their cytoplasm.

Prokaryotes have 70S ribosomes, while Eukaryotes have 80S ribosomes in their cytoplasm.

Fungi are the only kingdom with 100S ribosomes.

Plants have 70S ribosomes in their cytoplasm and 80S ribosomes in their chloroplasts.

Cytoplasm

Mitochondria

Chloroplasts

Ribosomes

Nervous system

Excretory system

Skeletal system

Digestive system

Meter (m)

Centimeter (cm)

Micrometer ($\mu m$)

Kilometer (km)

Chloroplast

Leaf

Xylem vessel

Palisade cell

Cell A

Cell B

Cell C

Cell D

Nucleus

Cytoplasm

Cell wall

Vacuole

Cellulose

Lipids

Water

Proteins

Lysosomes

Centrioles

Nucleolus

Golgi complex

$3$

$9$

$27$

$81$

To allow for the replication of DNA outside the nucleus

To permit the exit of mRNA and the entry of proteins needed for nuclear function

To allow mitochondria to enter the nucleus to provide energy

To prevent the entry of any substance into the nucleoplasm

DNA

Starch

Oxygen ($O_2$)

Proteins

From high to low concentration

From low to high concentration

Against gravity

Towards the center of the cell

Turgid

Plasmolysed

Isotonic

Lysis

Moves to the left

Moves to the right

Zero net movement

Particles stop moving

Smaller cubes have a smaller surface area.

Smaller cubes have a larger surface area to volume ratio.

Acid moves faster through smaller cubes.

Smaller cubes have a higher internal temperature.

Diffusion: Requires ATP from respiration.

Osmosis: Requires ATP from respiration.

Active transport: Requires ATP from respiration.

Facilitated diffusion: Requires ATP from respiration.

A large molecule at low temperature.

A small molecule with a large concentration gradient.

A large molecule with a small concentration gradient.

A small molecule at low temperature.

Increased temperature

Increased concentration gradient

Increased membrane thickness

Increased surface area

Diffusion

Osmosis

Active transport

Equilibrium

It would increase indefinitely as kinetic energy increases.

It would remain constant.

It would decrease as carrier proteins and respiratory enzymes denature.

It would decrease because the membrane becomes more solid.

Amino acids

Glucose

Glycerol

Starch

It makes the blood turn red

It allows nutrients and waste products to be transported easily

It prevents the blood from clotting

It keeps the body temperature at exactly 100°C

In the brain

In the liver

In the stomach

In the lungs

Adenine

Guanine

Insulin

Thymine

Water carries solid starch through the arteries.

Water dissolves glucose and urea in the blood plasma.

Water transports fatty acids by forming a solid emulsion.

Water moves amino acids by converting them into gases.

It allows DNA to be used for energy storage.

It makes the molecule compact and protects the base sequence.

It allows the DNA to dissolve easily in the cytoplasm.

It prevents the DNA from being copied.

A carbohydrate

A lipid

A protein

A DNA nucleotide

The high density of liquid water compared to ice.

The polarity of the water molecule which allows it to form hydrogen bonds.

The high latent heat of fusion.

The presence of dissolved oxygen in water.

Thermal insulation

Long-term energy storage

Buoyancy in marine mammals

Primary structural component of plant cell walls

Starch and protein

Starch and reducing sugar

Reducing sugar and lipid

Non-reducing sugar and protein

It determines the color of the enzyme

It allows the enzyme to move through the blood

It must be complementary to the shape of the substrate

It allows the enzyme to store energy

Synthesis

Digestion

Respiration

Photosynthesis

It will work twice as fast

It will change its substrate

Its active site will change shape and lose function

It will turn into an amino acid

Molecules move slower

Molecules collide more often and with more energy

The active site becomes larger

The substrate becomes more rigid

It acts as a source of energy

It is the medium in which molecules collide and react

It is needed to denature the enzymes after use

It changes the $pH$ to make enzymes work faster

The rate decreases

The rate stays the same

The rate increases linearly

The rate increases and then immediately stops

To break down lactose into glucose and galactose

To break down glucose into lactic acid

To convert milk proteins into solids

To synthesize lactose from simple sugars

The Intermediate concentration will decrease because its production is slowed while its conversion by Enzyme 2 continues.

The Intermediate concentration will increase because the inhibition of Enzyme 1 causes the pathway to reverse.

The Intermediate concentration will remain constant because Enzyme 2 will be activated to process the Product faster.

The Intermediate concentration will increase because the Precursor will be converted into the Intermediate by other enzymes.

The enzymes have more energy to change their shape

The molecules move faster, increasing the frequency and energy of collisions

The substrate molecules become smaller and easier to digest

The activation energy of the reaction is increased

The enzyme has reached its maximum temperature

The reaction has stopped because all substrate is gone

All available enzyme active sites are occupied by substrate molecules

The enzyme has been completely denatured

To provide buoyancy for the leaf

To allow $CO_2$ to diffuse to the palisade cells

To store oxygen for respiration at night

To act as a water reservoir

It will contain a lot of starch

It will be blue-black with iodine

It will contain no starch

It will turn green

Protection from herbivores

Gas exchange

Transport and support

Energy storage

The soil

Fertilizers

Sunlight

Water

To be closer to the spongy mesophyll

To reduce water loss by being in the shade

To allow more light to reach the palisade layer

To prevent oxygen from escaping too quickly

They represent the uptake of $CO_2$

They represent the production of oxygen

They represent the loss of water vapor

They represent the movement of glucose

Nitrification

Assimilation

Denitrification

Nitrogen fixation

A linear increase that never stops.

A curve that increases and then levels off (plateaus).

A bell-shaped curve that peaks and then drops to zero.

An initial decrease followed by a rapid increase.

It must be boiled in ethanol to remove the green pigment.

It must be kept in the dark to de-starch.

It must be washed in cold water to rehydrate the tissues.

It must be covered with black paper.

It is converted to starch for easier movement.

It is converted into sucrose because sucrose is less reactive and more efficient for transport.

It is converted into amino acids to prevent it from being used by the phloem cells.

It is converted into lipids to increase the energy density of the sap.

Scurvy

Marasmus

Anemia

Night blindness

Colon

Ileum

Duodenum

Rectum

Red meat

Milk and cheese

Citrus fruits

White bread

Large fat droplets are broken into smaller droplets

Fats are chemically changed into fatty acids

Proteins are broken into amino acids

Starch is converted into maltose

Oesophagus

Stomach

Pancreas

Large intestine

Protein

Carbohydrate

Fat (Lipid)

Vitamin C

It chemically breaks fats into fatty acids

It increases the surface area for lipase to act upon

It neutralizes the acid coming from the stomach

It allows fats to be absorbed directly into the capillaries

It is the main site of physical digestion using circular muscles.

It is the primary site for the absorption of digested food molecules into the blood and lymph.

It is the site where bile and pancreatic juice are first added to the food.

It is the site where cellulose is broken down by human enzymes.

Starch

Glycogen

A typical protein (polypeptide)

A triglyceride

Constipation

Diarrhea

Scurvy

Obesity

Xylem

Phloem

Cortex

Pith

They are made of living cells

They contain cytoplasm

They have walls reinforced with lignin

They transport sucrose and amino acids

They lose water and become flaccid

They gain water and become turgid

They lose their nucleus

They stop photosynthesizing

Cold, still, humid air

Warm, windy, dry air

Cold, windy, humid air

Warm, still, humid air

ATP from respiration in the xylem cells

Sunlight causing evaporation from the leaves

Active transport in the root hair cells

The breakdown of starch in the roots

From sink to source via xylem

From source to sink via xylem

From source to sink via phloem

From sink to source via phloem

By changing their thickness through the addition of lignin

By changing their turgidity through the movement of water

By moving closer together using contractile proteins

By dying and being replaced by new cells

The hydrostatic pressure gradient between the source and the sink.

The surface tension of the water within the sieve tube elements.

The beating of cilia-like structures inside the companion cells.

The gravitational pull on the heavy sucrose molecules.

The concentration of glucose in the phloem.

The temperature of the leaf surface.

The humidity of the surrounding air.

The surface area of the leaves.

transpiration; water uptake

water uptake; transpiration

photosynthesis; translocation

respiration; photosynthesis

Right atrium

Right ventricle

Left atrium

Left ventricle

Transporting heat around the body

Carrying oxygen using hemoglobin

Engulfing bacteria

Pumping blood through the heart

Increased lung capacity

A heart attack

Improved blood flow to the brain

Healthier heart muscle

Urea

Oxygen

Carbon dioxide

Hormones

Red blood cells

Lymphocytes

Plasma proteins

Platelets

It carries deoxygenated blood from the liver to the heart

It carries oxygenated blood from the heart to the liver

It carries nutrient-rich blood from the gut to the liver

It carries urea from the liver to the kidneys

Prevents backflow from the right ventricle into the right atrium

Prevents backflow from the left ventricle into the left atrium

Prevents backflow from the pulmonary artery into the right ventricle

Prevents backflow from the aorta into the left ventricle

Temporary chest pain that goes away with rest.

Death of a portion of the cardiac muscle due to a prolonged lack of oxygen.

A slight increase in heart rate during exercise.

The presence of a heart murmur due to a leaky valve.

They contain more red blood cells and more glucose.

They contain similar concentrations of ions but significantly fewer large plasma proteins.

They contain higher concentrations of urea and no white blood cells.

They are identical to plasma in every way.

Fish have a three-chambered heart that mixes blood.

Fish have a single circulation system where blood pressure drops significantly in the gill capillaries before reaching the rest of the body.

Fish blood does not contain hemoglobin, making oxygen transport inefficient.

Fish hearts only pump oxygenated blood, which is less efficient for the heart muscle itself.

To pump blood

To move trapped pathogens up to the throat

To help swallow food

To cool down the lungs

Because the old vaccine expires in one week

Because the flu virus changes its surface antigens

Because people forget they were vaccinated

Because the government requires it

Phagocytosis

Active immunity

Mechanical defense

Passive transport

Washing hands

Wearing flip-flops in communal showers

Wearing a face mask

Drinking plenty of water

Production of wax in the ears

Phagocytosis by white blood cells

The blink reflex of the eyes

The presence of hairs in the nose

The pathogen can no longer enter the person's body

The person's immune system can respond quickly to destroy the pathogen

The person's skin becomes completely impermeable to all microbes

The person no longer has any white blood cells

The cold is caused by bacteria that are resistant to all drugs

Cold viruses mutate frequently, changing their surface antigens

The human body cannot produce antibodies against respiratory viruses

Vaccines only work for diseases that are transmitted by vectors

The ability of the immune system to attack any foreign object in the body.

The fact that a specific antibody will only bind to an antigen with a complementary shape.

The speed at which the body produces a fever during an infection.

The specific way that antibiotics target only 70S ribosomes.

The body will produce more stomach acid to compensate for the lack of protein.

The body will be unable to synthesize enough antibodies and enzymes for an effective immune response.

The skin will become thicker, providing a better mechanical barrier.

The number of red blood cells will increase to carry more antibodies.

To produce mucus that traps dust and pathogens.

To sweep the layer of mucus containing trapped pathogens upward toward the throat.

To increase the surface area for the diffusion of oxygen into the blood.

To detect the presence of carbon dioxide in the air.

To hold more water

To speed up gas exchange by diffusion

To make the lungs heavier

To prevent air from leaving

In the blood in capillaries

In the cells of the toe

In the air inside the alveoli

In the pulmonary artery

Nitrogen

Carbon dioxide

Oxygen

Argon

Pulse rate

Heart rate

Breathing rate

Metabolic rate

$6.0\,dm^3/min$

$24.0\,dm^3/min$

$0.5\,dm^3/min$

$12.5\,dm^3/min$

To make it easy for the lungs to expand

To reduce the diffusion distance for gases

To prevent the entry of bacteria

To allow the alveoli to store more air

To produce carbon dioxide

For aerobic respiration to release energy

To keep the blood red

To prevent the lungs from collapsing

Cilia move a layer of mucus containing trapped particles upwards toward the throat to be swallowed

Cilia pump oxygen molecules directly into the capillaries from the bronchioles

Cilia are found only in the alveoli to help with the diffusion of gases

Cilia contract to pull the lungs open during a heavy inspiration

$O_2$ will decrease and $CO_2$ will increase

$O_2$ will increase and $CO_2$ will decrease

Both $O_2$ and $CO_2$ will increase as the person breathes faster

Both $O_2$ and $CO_2$ will stay the same because the room is sealed

It allows for passive exhalation as the lungs recoil to their original size

It allows the lungs to expand beyond the volume of the thoracic cavity

It prevents the lungs from collapsing if the pleural membrane is pierced

It ensures that the heart is compressed during every breath to assist circulation

Light and sound

ATP and heat

Glucose and starch

Oxygen and water

Distilled water

Soda lime

Glucose solution

Ethanol

It is destroyed

It is converted into glucose

It is lost to the environment as heat

It is stored as oxygen

Breathing is a chemical reaction; respiration is mechanical

Breathing is the exchange of gases; respiration is the release of energy from glucose

Breathing only happens in plants; respiration only happens in animals

There is no difference between the two

To produce glucose for the cells

To deliver oxygen and glucose to cells and remove carbon dioxide

To provide the site where respiration takes place

To absorb light energy for the mitochondria

A straight horizontal line

A continuously decreasing curve

A curve that increases and then peaks

A curve that decreases and then increases

The concentration of glucose will increase over time

The temperature of the solution will decrease

The concentration of ethanol will increase over time

The pH of the solution will increase as $CO_2$ is produced

An increase in the surface area of the alveoli.

An increase in the thickness of the alveolar wall.

An increase in the partial pressure gradient of oxygen.

An increase in the number of red blood cells passing the alveoli per minute.

The body cannot absorb all the oxygen from the air in a single breath.

The lungs produce oxygen as a byproduct of respiration.

Exhaled air only comes from the trachea where no gas exchange occurs.

The $16\%$ is actually $CO_2$ that is misidentified as oxygen.

Water

Carbon dioxide

Oxygen

Glucose

Liver

Heart

Kidney

Bladder

Fiber

Water from respiration

Inhaled argon

Undigested fat

Renal Pelvis

Renal Cortex

Renal Medulla

Ureter

To provide energy for the body

Because it is a toxic substance

To help the blood clot

To transport oxygen

No risk of infection

No need for any medication after surgery

The patient can lead a more normal life without restrictive treatments

The procedure is non-invasive

The concentration of salts decreases.

The concentration of salts increases.

The concentration of salts remains unchanged.

Salts are not excreted in urine.

Renal vein

Hepatic portal vein

Renal artery

Pulmonary artery

The kidney uses a lot of oxygen for the active transport of solutes.

The kidney does not receive any arterial blood.

Deoxygenated blood from the liver enters the kidney.

The glomerulus removes oxygen from the blood during ultrafiltration.

The carboxyl group ($-COOH$)

The amino group ($-NH_2$)

The R-group

The central carbon atom

Salts will move into the blood by active transport.

There will be no net movement of salts between the blood and the dialysis fluid.

All salts will move out of the blood into the dialysis fluid.

The patient's blood pressure will increase.

Insulin

Oestrogen

Adrenaline

Testosterone

To focus light on the retina

To control the size of the pupil

To protect the cornea

To convert light into electrical impulses

Connects relay neurons to muscles

Carries impulses from receptors to the CNS

Is found only in the brain

Produces hormones like insulin

Dendrite

Nucleus

Axon

Synapse

The shoot bends downwards because the high concentration of auxin inhibits cell elongation on the lower side.

The shoot bends upwards because the high concentration of auxin stimulates cell elongation on the lower side.

The shoot bends downwards because the low concentration of auxin stimulates cell elongation on the upper side.

The shoot bends upwards because the low concentration of auxin inhibits cell elongation on the upper side.

By increasing the size of the electrical impulse.

By changing the type of neurotransmitter used.

By increasing the frequency of the impulses.

By sending the impulse through thicker neurons.

Because it involves the brain's conscious thought.

Because it occurs without conscious deliberation.

Because it only happens when we are asleep.

Because it can be stopped if we think about it hard enough.

Insulin

Oestrogen

Adrenaline

Testosterone

Auxin accumulates on the lower side in both; it stimulates growth in the shoot but inhibits it in the root.

Auxin accumulates on the upper side in the root and the lower side in the shoot.

Auxin accumulates on the lower side in both and stimulates growth in both.

Auxin is not involved in root gravitropism; only shoot phototropism.

The metabolic rate increases to burn off the heat.

Vasoconstriction occurs to keep the heat away from the skin.

Sweat glands secrete fluid, which uses body heat to evaporate.

Erector muscles contract to trap a layer of air.

Cirrhosis

Chronic bronchitis

Lung cancer

Anemia

The antibiotics might have expired

The new infection might be viral

Using the wrong dose contributes to antibiotic resistance

All of the above

Tar

Glucose

Nicotine

Carbon monoxide

Increased calmness

Increased aggression ('roid rage')

Better sleep patterns

Improved memory

It mimics the effect of the hormone adrenaline

It mimics the effect of the hormone insulin

It increases the volume of the lungs

It slows down the rate of digestion

The remaining bacteria will all die naturally within a few days

The bacteria that survived are likely to be the most resistant ones

The bacteria will turn into viruses to avoid the antibiotic

The antibiotic will stay in the blood forever, so the patient is still protected

Improved appetite and weight gain

Severe muscle cramps and nausea

Increased ability to concentrate on complex tasks

A permanent decrease in the need for sleep

The use of antibiotics in viral infections

The natural mutation rate of bacteria coupled with the overuse of antibiotics

The lack of new vaccines being developed by scientists

The bacteria learning how to hide inside human red blood cells

Fungi are too large for the antibiotic molecules to enter

Fungi have a different cell wall composition (chitin) than bacteria (peptidoglycan)

Antibiotics only work in the presence of bacterial chlorophyll

Fungi produce their own antibiotics which neutralize the medicine

The cilia start producing mucus to protect themselves

The goblet cells are stimulated to produce more mucus due to irritation

The alveoli collapse and release their fluid into the bronchi

The smooth muscle in the trachea secretes mucus

Oxygen

Glucose

Urea

Amino acids

Zygotes

Clones

Gametes

Hybrids

For photosynthesis

For aerobic respiration

To soften the seed coat

To produce chlorophyll

Uterus

Placenta

Amniotic sac

Oviduct

Stigma and Style

Anther and Filament

Ovary and Ovule

Petal and Sepal

To produce egg cells through meiosis.

To provide a narrow opening that dilates during childbirth.

To secrete progesterone to maintain pregnancy.

To act as the primary site of fertilization.

Estrogen

Progesterone

Follicle Stimulating Hormone (FSH)

Testosterone

To ensure that the offspring have double the number of chromosomes as the parents.

To maintain the same chromosome number from generation to generation by producing haploid gametes.

To allow for rapid growth and repair of damaged tissues.

To produce diploid cells that can undergo fertilization.

To stimulate the release of an egg from the ovary.

To maintain and further thicken the uterine lining for potential implantation.

To cause the pituitary gland to release a surge of FSH.

To trigger the breakdown of the endometrium.

It involves the fusion of haploid nuclei.

It always requires two parents of the same species.

It produces offspring that are genetically identical to the parent.

It is the main source of genetic variation in a population.

$23$

$46$

$92$

$44$

All variation is caused by the environment.

All variation is caused by genes.

Variation can be continuous or discontinuous.

Variation only occurs in animals, not plants.

1

2

23

46

P1 generation

F1 generation

F2 generation

G1 generation

20%

30%

40%

60%

Heterozygous

Homozygous

Haploid

Polyploid

1

2

3

4

Chromosome

Gene

Genome

Codon

Mammals

Birds

Reptiles (like crocodiles)

Insects

Deletion

Insertion

Point mutation

Duplication

Any sperm can fuse with any egg

Only the largest egg is fertilized

Mutations are removed from the DNA

Genes are chosen by the parents

It causes all bacteria to die immediately

It acts as a selection pressure, favoring resistant individuals

It prevents bacteria from ever mutating

It turns all bacteria into viruses

Mutation

Meiosis

Random fertilization

Eating more protein

Thick layers of fat

Large ears with many blood vessels for heat loss

Small ears to prevent heat loss

Heavy, dark-colored fur

The individual aphids developed an immunity to the chemical over their lifetime after repeated exposure.

The insecticide caused a mutation in the aphids that immediately provided them with resistance.

Aphids that already possessed a resistant allele were more likely to survive and reproduce, passing the allele to their offspring.

The aphids learned to detect the chemical and avoided the parts of the crop that were sprayed.

Offspring always inherit only the 'tall' genes

Height is influenced by multiple genes and environmental factors like nutrition

Genes for height are always mutated during fertilization

The parents' height genes are deleted during meiosis

A population of fish developing camouflaged scales in a lake

A variety of wheat that produces a very high yield of grain

A species of cactus developing long spines to deter herbivores

Bacteria becoming resistant to a new antibiotic in the wild

The average body size of males will increase to improve their ability to fight off predators.

The mutation rate will increase to produce new alleles that specifically provide camouflage.

The average body size of males will decrease because the survival cost now outweighs the reproductive benefit of being large.

The phenotype of the birds will remain the same because the environment cannot influence the frequency of genetic traits.

A population being split into two by a new mountain range.

A sudden increase in the food supply for a population.

A single point mutation in a somatic cell.

A year of particularly heavy rainfall.

It is the total number of individuals in a population.

It is the set of all alleles of all genes in a population.

It is the specific location where a population lives.

It refers to the mutation rate of a single gene.

They break down too quickly

They can accumulate in the bodies of organisms higher up the food chain

They only kill one specific type of insect

They are very cheap to produce

Nitrogen

Methane

Helium

Argon

A group of different species

The place where an organism lives

The role of an organism in its environment

A network of food chains

To trap heat and keep the Earth warm

To protect the Earth from harmful ultraviolet (UV) radiation

To provide oxygen for breathing

To regulate the tides

Grass

Grasshopper

Lizard

Snake

An abundance of new territory

The accumulation of toxic metabolic waste products

A sudden increase in the birth rate

A decrease in the number of predators

Nitrification

Decomposition

Nitrogen fixation

Denitrification

It will lead to a decrease in the sea level globally

It releases trapped methane and carbon dioxide from decomposing organic matter

It will stop the process of nitrogen fixation in the soil

It reflects more sunlight back into space, cooling the Earth

An increase in the adaptive potential of the population

A random change in allele frequencies which can lead to a loss of genetic variation

A decrease in the rate of mutation across the entire genome

The immediate evolution of a new species better suited to the environment

Energy is cycled through the food web and reused by producers

Energy enters as light and leaves as heat

Energy is created by consumers through the process of respiration

Energy is stored indefinitely in the bodies of top predators

$0^{\circ}C$

$30^{\circ}C$ to $40^{\circ}C$

$80^{\circ}C$ to $90^{\circ}C$

$100^{\circ}C$

Ingredients are added and the product is harvested only at the end

The fermenter is never cleaned

Product is removed continuously as more food is added

No microorganisms are used

Chromosome

Nucleus

Plasmid

Chloroplast

Amylase

Lipase

Protease

Lactase

To provide the bacteria with the building blocks for protein synthesis

To act as a source of energy for aerobic respiration

To neutralize the acidic waste products

To prevent the growth of fungi

To make the bacteria healthier

To allow researchers to select and identify only the bacteria that have taken up the plasmid

To prevent the human gene from being destroyed

To kill other bacteria in the fermenter

The increased cost of the final food product

The possibility of people having allergic reactions to new proteins in the food

The increase in the yield of the crop

The reduction in the amount of land needed for farming

The accumulation of ethanol to toxic levels.

The decrease in the concentration of nitrogen gas.

The increase in the intensity of light.

The depletion of $CO_{2}$ in the solution.

To repair damage to its own genomic DNA.

To help the bacteria replicate its plasmid during binary fission.

To defend against viral infections by cutting up foreign viral DNA.

To allow the bacteria to absorb nutrients from its surroundings.

Distributing heat evenly throughout the mixture.

Breaking up large clumps of microorganisms to increase surface area.

Ensuring nutrients are in contact with all the cells.

Generating oxygen molecules from the water in the medium.

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Dead organisms buried millions of years ago

Volcanic rocks cooled by ocean water

Mineral crystals found in the Earth's mantle

Condensed atmospheric gases

Increasing the use of nuclear energy

Large-scale reforestation

Burning fossil fuels for electricity

Developing water purification systems

$C$

$CO$

$CH_4$

$CO_2$

Respiration

Photosynthesis

Combustion

Transpiration

$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$

$C + O_2 \rightarrow CO_2$

$CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O$

$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O$