AC-HPAT Biology 2025 Guide with complete solution
Chemical Digestion - ANSWERS-Chemical digestion involves breaking down the food into simpler
nutrients that can be used by the cells. Chemical digestion begins in the mouth when food
mixes with saliva. Saliva contains an enzyme (amylase) that begins the breakdown of
carbohydrates.
mechanical digestion - ANSWERS-Mechanical digestion involves physically breaking the food
into smaller pieces. Mechanical digestion begins in the mouth as the food is chewed. Chemical
digestion involves breaking down the food into simpler nutrients that can be used by the cells.
Chemical digestion begins in the mouth when food mixes with saliva.
Kidneys - ANSWERS-The kidneys perform many crucial functions, including maintaining overall
fluid balance. regulating and filtering minerals from blood. filtering waste materials from food,
medications, and toxic substances.
Xylem vs. Phloem - ANSWERS-Xylem transports only minerals and waters from the roots.
Phloem transports food materials that are prepared by the green parts of the plants to other
parts of the plant. Xylem is the dead tissues at maturity, but no cell contents. Phloem is the
living tissue, but not with the nucleus
Chloroplast - ANSWERS-Chloroplasts are organelles found in plant cells and eukaryotic algae
that conduct photosynthesis. Chloroplasts absorb sunlight and use it in conjunction with water
and carbon dioxide gas to produce food for the plant.
Pistil - ANSWERS-Pistil, the female reproductive part of a flower. The pistil, centrally located,
typically consists of a swollen base, the ovary, which contains the potential seeds, or ovules; a
,stalk, or style, arising from the ovary; and a pollen-receptive tip, the stigma, variously shaped
and often sticky.
Stamen - ANSWERS-The stamen (plural stamina or stamens) is the pollen-producing
reproductive organ of a flower. Collectively the stamens form the androecium.
Nitrogen Fixation - ANSWERS-Nitrogen fixation is a process by which molecular nitrogen in the
air is converted into ammonia (NH. 3) or related nitrogenous compounds in soil. Atmospheric
nitrogen is molecular dinitrogen, a relatively non-reactive molecule that is metabolically useless
to all but a few microorganisms.
Germination - ANSWERS-Germination is the process of seeds developing into new plants. ...
When water is plentiful, the seed fills with water in a process called imbibition. The water
activates special proteins, called enzymes, that begin the process of seed growth. First the seed
grows a root to access water underground.
Photosynthesis - ANSWERS-1. light dependent reaction
2. calvin cycle
Light dependent reaction - ANSWERS-· Light dependent reactions occur in the thylakoid
membrane of the chloroplasts and take place only when light is available. During these
reactions light energy is converted to chemical energy.
Chlorophyll and other pigments absorb energy from sunlight. This energy is transferred to the
photosystems responsible for photosynthesis
Water is used to provide electrons and hydrogen ions but also produces oxygen
The electrons and hydrogen ions are used to create ATP and NADPH. ATP is an energy storage
molecule. NADPH is an electron carrier/donor molecule. Both ATP and NADPH will be used in
the next stage of photosynthesis.
,Calvin Cycle - ANSWERS-· The Calvin Cycle reactions occur in the stroma of the chloroplasts.
Although these reactions can take place without light, the process requires ATP and NADPH
which were created using light in the first stage. Carbon dioxide and energy from ATP along with
NADPH are used to form glucose.
Pollination - ANSWERS-Pollination is the act of transferring pollen grains from the male anther
of a flower to the female stigma. The goal of every living organism, including plants, is to create
offspring for the next generation. One of the ways that plants can produce offspring is by
making seeds
Pancreas and Type 1 diabetes - ANSWERS-The pancreas is the organ that produces insulin, and it
plays a major role in regulating blood glucose levels. Type 1 diabetes occurs when the pancreas
does not make enough or any insulin.
How does insulin work in diabetes? - ANSWERS-Insulin pumps are small, computerized devices
that mimic the way the human pancreas works by delivering small doses of short acting insulin
continuously (basal rate). The device also is used to deliver variable amounts of insulin when a
meal is eaten (bolus)
chemotherapy - ANSWERS-Chemotherapy is a drug treatment that uses powerful chemicals to
kill fast-growing cells in your body. Chemotherapy is most often used to treat cancer, since
cancer cells grow and multiply much more quickly than most cells in the body. It targets cells
that grow and divide quickly, as cancer cells do. Unlike radiation or surgery, which target specific
areas, chemo can work throughout your body. But it can also affect some fast-growing healthy
cells, like those of the skin, hair, intestines, and bone marrow.
How can stem cells be used in the treatment of leukemia? And how effective is it? - ANSWERS-
Stem cell transplant replaces the leukemia cells in your bone marrow with new ones that make
blood. Your doctor can get the new stem cells from your own body or from a donor. Stem cell
transplantation is effective against leukemia. In many cases, however, the transferred immune
cells of the donor also attack the recipients' healthy tissue—often with fatal consequences. ...
Stem cell therapy offers people suffering from leukemia or bone-marrow cancer the chance of
full recovery.
, Why is laser technology more effective than conventional surgery in removing cancerous
tumours? - ANSWERS-Lasers are more precise than standard surgical tools (scalpels), so they do
less damage to normal tissues. As a result, patients usually have less pain, bleeding, swelling,
and scarring. With laser therapy, operations are usually shorter.
Urinary system - ANSWERS-· The urinary system, also known as the renal system or urinary
tract, consists of the kidneys, ureters, bladder, and the urethra. The purpose of the urinary
system is to eliminate waste from the body, regulate blood volume and blood pressure, control
levels of electrolytes and metabolites, and regulate blood pH
Nanotechnology - ANSWERS-Nanotechnology can provide rapid and sensitive detection of
cancer-related molecules, enabling scientists to detect molecular changes even when they occur
only in a small percentage of cells.
Mercury poisoning - ANSWERS-The most common cause of mercury poisoning is from
consuming too much methyl mercury or organic mercury, which is linked to eating seafood.
Small amounts of mercury are present in everyday foods and products, which may not affect
your health. Too much mercury, however, can be poisonous. Mercury salts affect primarily the
gastrointestinal tract and the kidneys, and can cause severe kidney damage; however, as they
cannot cross the blood-brain barrier easily, these salts inflict little neurological damage without
continuous or heavy exposure.
How can ultraviolet light from the sun affect the cells of the human eye? - ANSWERS-UV rays
may lead to macular degeneration, a leading cause of vision loss for older Americans. UV rays,
especially UV-B rays, may also cause some kinds of cataracts. A cataract is a clouding of the
eye's natural lens, the part of the eye that focuses the light we see.
Macromolecules - ANSWERS-Macromolecules are large molecules composed of thousands of
covalently connected atoms. Carbohydrates, lipids, proteins, and nucleic acids are all
macromolecules. Macromolecules are formed by many monomers linking together, forming a
polymer.
Chemical Digestion - ANSWERS-Chemical digestion involves breaking down the food into simpler
nutrients that can be used by the cells. Chemical digestion begins in the mouth when food
mixes with saliva. Saliva contains an enzyme (amylase) that begins the breakdown of
carbohydrates.
mechanical digestion - ANSWERS-Mechanical digestion involves physically breaking the food
into smaller pieces. Mechanical digestion begins in the mouth as the food is chewed. Chemical
digestion involves breaking down the food into simpler nutrients that can be used by the cells.
Chemical digestion begins in the mouth when food mixes with saliva.
Kidneys - ANSWERS-The kidneys perform many crucial functions, including maintaining overall
fluid balance. regulating and filtering minerals from blood. filtering waste materials from food,
medications, and toxic substances.
Xylem vs. Phloem - ANSWERS-Xylem transports only minerals and waters from the roots.
Phloem transports food materials that are prepared by the green parts of the plants to other
parts of the plant. Xylem is the dead tissues at maturity, but no cell contents. Phloem is the
living tissue, but not with the nucleus
Chloroplast - ANSWERS-Chloroplasts are organelles found in plant cells and eukaryotic algae
that conduct photosynthesis. Chloroplasts absorb sunlight and use it in conjunction with water
and carbon dioxide gas to produce food for the plant.
Pistil - ANSWERS-Pistil, the female reproductive part of a flower. The pistil, centrally located,
typically consists of a swollen base, the ovary, which contains the potential seeds, or ovules; a
,stalk, or style, arising from the ovary; and a pollen-receptive tip, the stigma, variously shaped
and often sticky.
Stamen - ANSWERS-The stamen (plural stamina or stamens) is the pollen-producing
reproductive organ of a flower. Collectively the stamens form the androecium.
Nitrogen Fixation - ANSWERS-Nitrogen fixation is a process by which molecular nitrogen in the
air is converted into ammonia (NH. 3) or related nitrogenous compounds in soil. Atmospheric
nitrogen is molecular dinitrogen, a relatively non-reactive molecule that is metabolically useless
to all but a few microorganisms.
Germination - ANSWERS-Germination is the process of seeds developing into new plants. ...
When water is plentiful, the seed fills with water in a process called imbibition. The water
activates special proteins, called enzymes, that begin the process of seed growth. First the seed
grows a root to access water underground.
Photosynthesis - ANSWERS-1. light dependent reaction
2. calvin cycle
Light dependent reaction - ANSWERS-· Light dependent reactions occur in the thylakoid
membrane of the chloroplasts and take place only when light is available. During these
reactions light energy is converted to chemical energy.
Chlorophyll and other pigments absorb energy from sunlight. This energy is transferred to the
photosystems responsible for photosynthesis
Water is used to provide electrons and hydrogen ions but also produces oxygen
The electrons and hydrogen ions are used to create ATP and NADPH. ATP is an energy storage
molecule. NADPH is an electron carrier/donor molecule. Both ATP and NADPH will be used in
the next stage of photosynthesis.
,Calvin Cycle - ANSWERS-· The Calvin Cycle reactions occur in the stroma of the chloroplasts.
Although these reactions can take place without light, the process requires ATP and NADPH
which were created using light in the first stage. Carbon dioxide and energy from ATP along with
NADPH are used to form glucose.
Pollination - ANSWERS-Pollination is the act of transferring pollen grains from the male anther
of a flower to the female stigma. The goal of every living organism, including plants, is to create
offspring for the next generation. One of the ways that plants can produce offspring is by
making seeds
Pancreas and Type 1 diabetes - ANSWERS-The pancreas is the organ that produces insulin, and it
plays a major role in regulating blood glucose levels. Type 1 diabetes occurs when the pancreas
does not make enough or any insulin.
How does insulin work in diabetes? - ANSWERS-Insulin pumps are small, computerized devices
that mimic the way the human pancreas works by delivering small doses of short acting insulin
continuously (basal rate). The device also is used to deliver variable amounts of insulin when a
meal is eaten (bolus)
chemotherapy - ANSWERS-Chemotherapy is a drug treatment that uses powerful chemicals to
kill fast-growing cells in your body. Chemotherapy is most often used to treat cancer, since
cancer cells grow and multiply much more quickly than most cells in the body. It targets cells
that grow and divide quickly, as cancer cells do. Unlike radiation or surgery, which target specific
areas, chemo can work throughout your body. But it can also affect some fast-growing healthy
cells, like those of the skin, hair, intestines, and bone marrow.
How can stem cells be used in the treatment of leukemia? And how effective is it? - ANSWERS-
Stem cell transplant replaces the leukemia cells in your bone marrow with new ones that make
blood. Your doctor can get the new stem cells from your own body or from a donor. Stem cell
transplantation is effective against leukemia. In many cases, however, the transferred immune
cells of the donor also attack the recipients' healthy tissue—often with fatal consequences. ...
Stem cell therapy offers people suffering from leukemia or bone-marrow cancer the chance of
full recovery.
, Why is laser technology more effective than conventional surgery in removing cancerous
tumours? - ANSWERS-Lasers are more precise than standard surgical tools (scalpels), so they do
less damage to normal tissues. As a result, patients usually have less pain, bleeding, swelling,
and scarring. With laser therapy, operations are usually shorter.
Urinary system - ANSWERS-· The urinary system, also known as the renal system or urinary
tract, consists of the kidneys, ureters, bladder, and the urethra. The purpose of the urinary
system is to eliminate waste from the body, regulate blood volume and blood pressure, control
levels of electrolytes and metabolites, and regulate blood pH
Nanotechnology - ANSWERS-Nanotechnology can provide rapid and sensitive detection of
cancer-related molecules, enabling scientists to detect molecular changes even when they occur
only in a small percentage of cells.
Mercury poisoning - ANSWERS-The most common cause of mercury poisoning is from
consuming too much methyl mercury or organic mercury, which is linked to eating seafood.
Small amounts of mercury are present in everyday foods and products, which may not affect
your health. Too much mercury, however, can be poisonous. Mercury salts affect primarily the
gastrointestinal tract and the kidneys, and can cause severe kidney damage; however, as they
cannot cross the blood-brain barrier easily, these salts inflict little neurological damage without
continuous or heavy exposure.
How can ultraviolet light from the sun affect the cells of the human eye? - ANSWERS-UV rays
may lead to macular degeneration, a leading cause of vision loss for older Americans. UV rays,
especially UV-B rays, may also cause some kinds of cataracts. A cataract is a clouding of the
eye's natural lens, the part of the eye that focuses the light we see.
Macromolecules - ANSWERS-Macromolecules are large molecules composed of thousands of
covalently connected atoms. Carbohydrates, lipids, proteins, and nucleic acids are all
macromolecules. Macromolecules are formed by many monomers linking together, forming a
polymer.
