Study Guide for BIOL 1040 Final Exam

Vocabulary flashcards based on the key concepts and terms outlined in the study guide.

dependent variable

The variable that is measured or observed in an experiment.

independent variable

The variable that is manipulated or changed in an experiment.

controlled variable

Factors that are kept constant to ensure that any changes in the dependent variable are due to the independent variable.

experimental group

The group in an experiment that receives the treatment or is exposed to the independent variable.

control group

The group that does not receive the experimental treatment and is used as a benchmark.

natural selection

The process by which organisms better adapted to their environment tend to survive and produce more offspring.

adaptation

A trait that improves an organism's ability to survive and reproduce in a particular environment.

fitness

The ability of an organism to survive and reproduce in its environment.

selectively permeable

A property of cell membranes that allows certain molecules to pass through while blocking others.

hydrophilic

Having an affinity for water; water-soluble.

hydrophobic

Repelling water; not water-soluble.

diffusion

The process by which molecules spread from areas of high concentration to areas of low concentration.

osmosis

The diffusion of water across a selectively permeable membrane.

peptidoglycan

A structural component of bacterial cell walls.

prokaryotes

Single-celled organisms without a nucleus; examples include bacteria and archaea.

eukaryotes

Organisms composed of one or more cells that contain a nucleus and organelles.

cell membrane

The barrier surrounding the cell, controlling what enters and exits.

nucleus

The organelle that houses the cell's DNA.

ribosomes

Organelles that synthesize proteins.

mitochondria

Organelles responsible for energy production in cells.

chloroplasts

Organelles in plants that conduct photosynthesis.

endoplasmic reticulum

An organelle involved in protein and lipid synthesis.

cell wall

A rigid structure that provides support and protection to plant cells.

gas exchange

The process of exchanging oxygen and carbon dioxide between the body and the environment.

capillaries

Small blood vessels where gas exchange occurs.

alveoli

Tiny air sacs in the lungs where gas exchange takes place.

pathogen

An organism that causes disease.

capsid

The protein shell of a virus.

host

An organism that harbors a virus or parasite.

antigen

A substance that induces an immune response.

antibody

A protein produced by the immune system to identify and neutralize pathogens.

enzyme

A protein that catalyzes biochemical reactions.

carbohydrates

Molecules made of sugar units that provide energy.

proteins

Large biomolecules made of amino acids that perform various functions in the body.

nucleic acids

Biomolecules such as DNA and RNA that carry genetic information.

macromolecule

A large complex molecule, such as proteins, nucleic acids, and carbohydrates.

micronutrient

Essential nutrients required by the body in small amounts, such as vitamins and minerals.

hormone

A signaling molecule produced by glands that regulate various physiological processes.

insulin

A hormone that regulates blood glucose levels by facilitating cellular glucose uptake.

glucagon

A hormone that raises blood glucose levels by promoting the release of glucose from the liver.

mutation

A change in the DNA sequence that can lead to genetic diversity.

cancer

A disease characterized by uncontrolled cell division.

explain why natural selection results in adaptation of populations

Natural selection leads to adaptation because individuals with favorable traits survive and reproduce more successfully, passing those traits to future generations. Unfavorable traits become less common as individuals with them are less likely to survive and reproduce. Over time, the population becomes better suited to its environment.

explain evolution as a change in allele frequencies of a population over time

Evolution is the change in the allele frequencies (the versions of a gene) within a population over time. As certain alleles provide advantages for survival and reproduction, they become more common, while less beneficial alleles decrease. Over many generations, these small genetic changes can lead to significant differences in the population.

explain why genetic variation is important in a population and what causes genetic variation

Genetic variation is important because it gives a population the ability to adapt to changing environments — without variation, all individuals would be affected the same way by threats like diseases or climate changes, and the whole population could be wiped out. With variation, some individuals are more likely to survive and pass on their traits.

Genetic variation is caused by mutations (random changes in DNA), genetic recombination during sexual reproduction (mixing of genes from two parents), and gene flow (when individuals move between populations and introduce new genes).

explain how natural selection has resulted in antibiotic resistant bacteria and viruses

Natural selection has led to antibiotic-resistant bacteria and viruses because when antibiotics or antiviral drugs are used, they kill most of the susceptible microbes. However, a few may have random mutations that make them resistant. These resistant ones survive, reproduce, and pass on their resistance genes. Over time, the population becomes mostly resistant because the favorable (resistant) traits are naturally selected.

describe the structure of membranes

Cell membranes are made of a phospholipid bilayer — two layers of phospholipids with their hydrophobic (water-fearing) tails facing inward and their hydrophilic (water-loving) heads facing outward toward the water inside and outside the cell.

Embedded proteins are scattered throughout this bilayer. Some proteins span the entire membrane (integral proteins), while others are only on the surface (peripheral proteins).

describe how antibiotics work

Antibiotics work by targeting key parts of bacterial cells that humans don't have, which helps kill the bacteria without harming human cells.

They can:

• Disrupt the bacterial cell wall, causing the bacteria to burst (like penicillin).

• Block protein production that bacteria need to grow and function.

• Interfere with DNA replication so bacteria can't reproduce.

• Inhibit metabolism, stopping bacteria from making the molecules they need to survive.

Different antibiotics attack different bacterial functions depending on the type.

describe the role of red blood cells and hemoglobin in transporting oxygen

Red blood cells (RBCs) carry oxygen from the lungs to the body’s tissues. Inside red blood cells, a protein called hemoglobin binds to oxygen molecules. Each hemoglobin can carry up to four oxygen molecules at a time. As blood flows through the body, hemoglobin releases the oxygen where it’s needed, helping cells make energy.

describe how carbon dioxide is transported in the blood

• Most CO₂ (about 70%) is carried as bicarbonate ions (HCO₃⁻) formed when CO₂ reacts with water in the blood.

• Some CO₂ (about 20-23%) binds directly to hemoglobin (not at the oxygen-binding sites).

• A small amount (about 7-10%) is dissolved directly in the plasma.

This system helps remove waste CO₂ from cells and carry it back to the lungs to be exhaled.

describe the role of simple diffusion in gas exchange in the lungs and body tissue

Simple diffusion is how gases like oxygen and carbon dioxide move during gas exchange.

In the lungs, oxygen diffuses from the air in the alveoli (where it's at a high concentration) into the blood (where oxygen is lower). At the same time, carbon dioxide diffuses from the blood (where CO₂ is high) into the alveoli to be exhaled.

In the body tissues, oxygen diffuses from the blood (high oxygen) into the cells (low oxygen), and carbon dioxide moves from the cells (high CO₂) into the blood (low CO₂)

name and list examples of the body's three lines of immune defense

1. First Line of Defense: Physical and Chemical Barriers

These are the body's initial defenses to block pathogens from entering.

• Skin (acts as a physical barrier)

• Mucous membranes (in the nose, throat, digestive tract)

• Tears, saliva, and sweat (contain enzymes like lysozyme that break down pathogens)

• Stomach acid (kills ingested pathogens)

• Cilia in the respiratory tract (trap and move particles out of the lungs)

2. Second Line of Defense: Innate Immune Response

This is activated if pathogens get past the first line of defense. It includes:

• Phagocytes (like macrophages and neutrophils, which engulf and digest pathogens)

• Inflammation (increases blood flow to affected areas to help fight infection)

• Fever (raises body temperature to help kill or inhibit pathogens)

• Antimicrobial proteins (like interferons that inhibit viral replication)

3. Third Line of Defense: Adaptive Immune Response

This is a more specific response that targets pathogens the body has encountered before.

• T cells (destroy infected cells or help coordinate the immune response)

• B cells (produce antibodies that specifically target and neutralize pathogens)

• Memory cells (remember pathogens, allowing faster and stronger responses in future infections)

describe how viruses infect and replicate in host cells

1. Attachment

The virus attaches to a specific receptor on the surface of the host cell. The receptors are often proteins or sugars that the virus specifically recognizes.

2. Entry

Once attached, the virus or its genetic material (RNA or DNA) enters the host cell. This can happen through fusion with the cell membrane or by endocytosis (where the cell engulfs the virus).

3. Uncoating

Inside the host cell, the virus's outer coat (capsid) is removed, releasing its genetic material into the host cell’s cytoplasm or nucleus.

4. Replication and Transcription

The viral genome takes control of the host cell’s machinery. It directs the host to replicate viral genetic material and produce viral proteins. This can occur in the host’s nucleus (for DNA viruses) or in the cytoplasm (for RNA viruses).

5. Assembly

The newly made viral genomes and proteins are assembled into new viral particles inside the host cell.

6. Budding or Cell Lysis

The new viruses are either transported to the cell surface in vesicles (budding) or cause the cell to burst open (lysis), releasing new viral particles into the surrounding environment to infect more cells.

This process can damage or kill the host cell.

explain why vaccinations lead to rapid immune response

Vaccinations lead to a rapid immune response because they "train" the immune system to recognize and respond to specific pathogens without causing the disease. Here's how it works:

1. Exposure to Antigens: Vaccines contain weakened, inactivated, or pieces of a pathogen (like proteins or antigens) that stimulate the immune system. These are not enough to cause illness but are enough for the body to recognize them.

2. Activation of B and T Cells: When the vaccine is introduced, the immune system recognizes the foreign antigens as harmful. B cells produce antibodies, while T cells help destroy infected cells or coordinate the immune response.

3. Memory Cells Formation: After exposure to the vaccine, the immune system creates memory cells (both memory B cells and T cells). These cells "remember" the pathogen and stay in the body long-term.

4. Faster Response on Re-exposure: If the person is later exposed to the actual pathogen, the immune system can quickly recognize it and launch a rapid and strong immune response because the memory cells are already prepared to fight it off.

This process leads to immunity without the person getting sick from the disease itself.

explain the importance of B cells and memory cells for immune responses

B cells produce antibodies that help identify and neutralize pathogens. After an infection or vaccination, memory cells are formed, which "remember" the pathogen. If the body encounters the same pathogen again, memory cells allow the immune system to respond much more quickly and effectively, providing long-term immunity.

covalent bond

a type of chemical bond where two atoms share one or more pairs of electrons in order to achieve stability, usually by filling their outer electron shells. This bond typically forms between nonmetals.

monomer

a small, simple molecule that can bind with other monomers to form a larger, more complex structure called a polymer. Monomers are the building blocks of polymers.

polymer

a large, complex molecule made up of repeated smaller units called monomers that are chemically bonded together. Polymers can be natural (like DNA or proteins) or synthetic (like plastic or nylon).

macromolecule

a large, complex molecule composed of thousands of atoms. They are typically formed by the bonding of smaller units, such as monomers, and are essential for life. There are four major types of macromolecules in living organisms:

1. Proteins (made of amino acids)

2. Nucleic acids (DNA and RNA, made of nucleotides)

3. Carbohydrates (made of sugar monomers)

4. Lipids (though not made of repeating monomers, they are considered macromolecules due to their size and importance)

macronutrient

A macronutrient is a type of nutrient that is required by the body in large amounts to provide energy and support vital functions. The three main types of macronutrients are:

1. Carbohydrates – Provide a primary source of energy.

2. Proteins – Help with growth, repair, and maintenance of tissues.

3. Fats – Provide long-term energy storage, protect organs, and help absorb certain vitamins.

metabolism

refers to all the chemical reactions that occur within a living organism to maintain life. These reactions allow the body to convert food into energy, build and repair cells, and regulate essential processes like growth and waste elimination. Metabolism is divided into two main categories:

1. Anabolism – the process of building complex molecules (like proteins and DNA) from simpler ones, which requires energy.

2. Catabolism – the process of breaking down complex molecules (like carbohydrates and fats) into simpler ones, releasing energy.

activation energy

the minimum amount of energy required to start a chemical reaction.

describe the structure of atoms and molecules

Atoms are made up of protons, neutrons, and electrons, with protons and neutrons in the nucleus and electrons orbiting in shells. Molecules are formed when two or more atoms bond, either by sharing electrons (covalent bonds) or transferring electrons (ionic bonds). Molecules can range from simple (like O₂) to complex (like DNA).

monosaccharide

the simplest type of carbohydrate, made of just one sugar molecule.

polysaccharide

a large carbohydrate made up of many monosaccharide (sugar) units linked together.

DNA

(Deoxyribonucleic Acid) is the molecule that stores genetic information in all living organisms. It carries the instructions needed for an organism’s growth, development, functioning, and reproduction.

DNA is made of two strands twisted into a double helix, with each strand made of building blocks called nucleotides. Each nucleotide has three parts:

• A sugar (deoxyribose)

• A phosphate group

• A nitrogen base (Adenine [A], Thymine [T], Cytosine [C], or Guanine [G])

The bases pair specifically: A pairs with T, and C pairs with G.

RNA

(Ribonucleic Acid) is a single-stranded molecule that helps carry out the instructions stored in DNA. It plays a key role in making proteins and controlling gene activity.

RNA is made of nucleotides too, but with a few differences from DNA:

• The sugar is ribose (instead of deoxyribose).

• It uses the base uracil (U) instead of thymine (T) — so A pairs with U in RNA.

• It’s usually single-stranded, not a double helix.

There are different types of RNA, like mRNA (messenger RNA), tRNA (transfer RNA), and rRNA (ribosomal RNA), each with a special job in protein synthesis.

triglyceride

a type of fat (lipid) made up of one glycerol molecule and three fatty acid chains. It's a major form of energy storage in animals and plants.

phospholipid

a special type of lipid made of two fatty acid tails (which are hydrophobic, or water-fearing) and a phosphate head (which is hydrophilic, or water-loving).

Phospholipids are important because they form the main structure of cell membranes, arranging themselves into a bilayer where the heads face outward toward water and the tails face inward, away from water.

steroid

a type of lipid made of four fused carbon rings.

Steroids serve important roles in the body, like:

• Acting as hormones (e.g., estrogen, testosterone, cortisol)

• Being part of cell membranes (e.g., cholesterol helps keep membranes flexible)

enzyme

a protein that speeds up chemical reactions in the body by lowering the activation energy needed for the reaction to happen.

Enzymes are specific — each one works with a particular molecule called a substrate, fitting together like a lock and key. After the reaction, the enzyme remains unchanged and can be reused.

match each monomer with their polymers

• Monosaccharide → Polysaccharide (example: starch, cellulose)

• Amino acid → Protein (polypeptide)

• Nucleotide → Nucleic acid (DNA or RNA)

• Fatty acids + Glycerol → Lipids (like triglycerides or phospholipids)*

name the two groups of micronutrients and state their functions

1. Vitamins:

• Function: Vitamins are essential for energy production, immune function, skin health, and cell repair. They act as coenzymes in many biochemical reactions.

• Examples:

  • Vitamin A – supports vision and immune function.

  • Vitamin C – aids in collagen formation, wound healing, and immune defense.

  • Vitamin D – helps with calcium absorption for bone health.

2. Minerals:

• Function: Minerals are important for maintaining fluid balance, nerve function, bone health, and enzyme activation.

• Examples:

  • Calcium – essential for strong bones and teeth.

  • Iron – vital for oxygen transport in blood.

  • Potassium – helps maintain proper heart and muscle function.

describe the function of enzymes and how they work

Enzymes are proteins that speed up chemical reactions by lowering the amount of activation energy needed for the reaction to occur.

They work by binding to a specific molecule called the substrate at a special area known as the active site. The enzyme and substrate fit together like a lock and key (or sometimes like an induced fit where the enzyme slightly changes shape). After the reaction happens, the enzyme releases the new product and remains unchanged, ready to be used again.

In short, enzymes make reactions faster and more efficient without being used up themselves!

mouth

The mouth is the first part of the digestive system and has two main functions:

1. Mechanical digestion: The teeth break down food into smaller pieces by chewing (mastication), making it easier to swallow and digest.

2. Chemical digestion: Saliva, produced by salivary glands, contains enzymes like amylase that begin breaking down carbohydrates into simpler sugars.

The mouth also helps form the food into a soft mass called a bolus for easier swallowing.

salivary glands

Salivary glands are glands in the mouth that produce saliva, which plays a key role in digestion and oral health.

Their main functions are:

• Moistening food to make it easier to chew and swallow.

• Starting chemical digestion by releasing the enzyme amylase, which begins breaking down carbohydrates.

• Protecting the mouth by washing away food particles and bacteria.

esophagus

a muscular tube that connects the mouth to the stomach.

Its main function is to transport food and liquids from the mouth to the stomach using rhythmic muscle movements called peristalsis. These wave-like contractions push the food downward after swallowing.

The esophagus doesn’t digest food — it just moves it!

stomach

Its main functions are:

• Mechanical digestion: The stomach muscles churn and mix food.

• Chemical digestion: It releases gastric juices (including acid and enzymes like pepsin) that break down proteins into smaller molecules.

• Storage: It holds food temporarily and releases it slowly into the small intestine.

The stomach turns food into a thick, soupy mixture called chyme before it moves on.

small intestine

The small intestine is the main site for digestion and nutrient absorption.

Its key functions are:

• Digestion: Enzymes from the pancreas and bile from the liver help break down proteins, carbohydrates, and fats.

• Absorption: Tiny finger-like structures called villi and microvilli increase the surface area to absorb nutrients into the bloodstream.

Most of the nutrients your body needs are absorbed here!

large intestine

mainly absorbs water and salts from the material that hasn't been digested, turning it into solid waste (feces).

Its key functions are:

• Water absorption: Prevents dehydration by reclaiming water.

• Formation and storage of feces: Prepares waste for elimination.

• Houses helpful bacteria: These bacteria help break down some remaining materials and produce certain vitamins, like vitamin K.

liver

its main job is to produce bile, a substance that helps break down and absorb fats in the small intestine.

Other key functions of the liver include:

• Detoxifying harmful substances from the blood.

• Storing nutrients like glycogen (a form of stored sugar).

• Making proteins important for blood clotting and other processes.

gall bladder

stores and concentrates bile produced by the liver.

pancreas

• Digestive function: It produces digestive enzymes (like lipase, amylase, and protease) that are released into the small intestine to help break down fats, carbohydrates, and proteins.

• Hormonal function: It produces hormones like insulin and glucagon that regulate blood sugar levels.

So, the pancreas helps with both digestion and blood sugar control!

where does the majority of water and nutrient absorption occur

The majority of water and nutrient absorption occurs in the small intestine. After the small intestine, any remaining water is absorbed in the large intestine.

explain the role of insulin and glucagon in controlling blood glucose levels

insulin lowers blood glucose, and glucagon raises it, ensuring your body maintains a stable level of glucose.

explain the causes of type I and type II diabetes

Type 1 diabetes is an autoimmune disease where the immune system destroys insulin-producing cells in the pancreas, leading to no insulin production. It typically develops in children or young adults.

Type 2 diabetes occurs when the body becomes resistant to insulin or produces insufficient insulin. It is often linked to obesity, poor diet, and lack of exercise, and typically develops in adults.

In short, Type 1 is due to a lack of insulin production, while Type 2 is caused by insulin resistance.

aerobic respiration equation

Glucose+Oxygen→Carbon dioxide+Water+Energy (ATP)

Explain aerobic respiration in terms of energy conversion (breaking chemical bonds in
carbohydrates to release energy and to make ATP)

In aerobic respiration, the body breaks chemical bonds in glucose (a carbohydrate) to release energy.

This energy is then used to make ATP (adenosine triphosphate), which is the main energy molecule cells use to perform work.

Oxygen is required in this process to help fully break down glucose into carbon dioxide and water. Most of the energy stored in the glucose bonds is captured and transferred into ATP, which powers cellular activities.

Explain respiration’s role in ecosystems

Respiration provides energy for organisms by breaking down sugars and also releases carbon dioxide, which plants reuse in photosynthesis. This helps maintain the flow of energy and the carbon cycle in ecosystems.

Contrast fermentation with aerobic respiration and state why fermentation is important

Fermentation and aerobic respiration both release energy from food, but they are different:

• Aerobic respiration uses oxygen to fully break down glucose, producing lots of ATP, along with carbon dioxide and water.

• Fermentation happens without oxygen and produces much less ATP. It only partially breaks down glucose and creates byproducts like lactic acid (in animals) or alcohol and carbon dioxide (in yeast).

Fermentation is important because it allows cells to keep making some ATP when oxygen isn’t available, helping organisms survive in low-oxygen environments

Explain the concept of food as fuel

Food acts as fuel by being broken down into smaller molecules that are used to make energy (ATP), which powers all body activities.

energy

the ability to do work

autotroph

an organism that makes its own food using energy from sunlight (through photosynthesis) or chemical reactions (through chemosynthesis).

heterotroph

an organism that cannot make its own food and must consume other organisms for energy and nutrients.

producer

produces its own food

consumer

must consume other organisms for energy

ATP

the primary energy currency of the cell. It stores and provides energy for many cellular processes.

State and explain the Law of Conservation of Energy

energy cannot be created or destroyed, only converted from one form to another.

Write the equation for photosynthesis

Carbon dioxide+Water+Light energy→Glucose+Oxygen

Explain photosynthesis in terms of energy conversion

the process where plants convert light energy into chemical energy stored in glucose. Light energy is absorbed by chlorophyll, splitting water molecules and producing ATP and NADPH. These energy carriers help convert carbon dioxide into glucose, storing energy in the chemical bonds of the carbohydrate.