BIOL 1406 Final Exam

What is the Scientific Method?

A systematic approach to research that involves making observations, forming hypotheses, conducting experiments, and analyzing data.

What is a Hypothesis?

A proposed explanation for a phenomenon, which can be tested through experimentation.

What is a Null Hypothesis?

A statement that there is no effect or no difference, used as a default position until evidence suggests otherwise.

What is the Independent Variable?

The variable that is manipulated or changed in an experiment to test its effects.

What is the Dependent Variable?

The variable that is measured or observed in an experiment, affected by changes in the independent variable.

What are Replicates?

Repetitions of an experiment or observations that help ensure reliability and validity of results.

Can you prove your hypothesis?

You cannot prove a hypothesis definitively; you can only support or refute it based on experimental evidence.

What are the main parts of the Cell Theory?

1. All living organisms are composed of cells. 2. The cell is the basic unit of life. 3. All cells arise from pre-existing cells.

What is the difference between Inductive and Deductive Reasoning?

Inductive reasoning involves drawing general conclusions from specific observations, while deductive reasoning starts with general principles to predict specific outcomes.

What is the difference between Qualitative and Quantitative Measurements?

Qualitative measurements describe characteristics or qualities, while quantitative measurements involve numerical data.

What is Evolution?

The change in the heritable characteristics of biological populations over successive generations.

What is Natural Selection?

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

What is a Feedback System?

A biological mechanism that regulates processes by using the output of a system to control its input.

What is Positive Feedback?

A process that amplifies or increases change, leading to a greater output.

What is Negative Feedback?

A process that counteracts change, maintaining stability in a system.

What is Matter?

Anything that has mass and occupies space.

What are Atoms?

The basic units of matter, consisting of protons, neutrons, and electrons.

What is Atomic Number?

The number of protons in the nucleus of an atom, which determines the element's identity.

What is Atomic Mass?

The weighted average mass of an atom's isotopes, measured in atomic mass units (amu).

What are Isotopes?

Atoms of the same element that have the same number of protons but different numbers of neutrons.

What is the Octet Rule?

The principle that atoms tend to bond in such a way that they have eight electrons in their outermost shell, achieving stability.

What is Electronegativity?

The tendency of an atom to attract electrons in a chemical bond.

What is the difference between an Element and a Compound?

An element is a pure substance made of one type of atom, while a compound is a substance formed from two or more different types of atoms chemically bonded together.

What are Valence Electrons?

Electrons in the outermost shell of an atom that are involved in forming bonds.

What is a Polar Molecule?

A molecule that has a partial positive charge on one end and a partial negative charge on the other due to unequal sharing of electrons.

What type of bond holds two water molecules together?

Hydrogen bonds.

What type of bond holds the Oxygen and Hydrogen atoms within a molecule of water together?

Covalent bonds.

What are the important properties of Water?

High heat capacity, solvent properties, cohesion, adhesion, and less dense as a solid.

What is Adhesion?

The tendency of water molecules to stick to other substances.

What is Cohesion?

The tendency of water molecules to stick to each other.

Why does ice float?

Ice is less dense than liquid water due to the hydrogen bonds forming a crystalline structure.

Why is the ability of ice to float important?

It insulates bodies of water, allowing aquatic life to survive in winter.

Why does salt dissolve in water but oil does not?

Salt is ionic and polar, allowing it to interact with water, while oil is nonpolar and does not mix with water.

What is Chromatography?

A technique used to separate components of a mixture based on their movement through a stationary phase.

What is a Buffer?

A solution that resists changes in pH when acids or bases are added, maintaining a stable environment.

What are the Four major types of organic molecules?

Carbohydrates, lipids, proteins, and nucleic acids.

What is a Monomer?

A small, basic molecular unit that can join together to form polymers.

What is a Polymer?

A large molecule made up of repeating monomer units.

What is Dehydration Synthesis?

A chemical reaction that involves the loss of water to join two molecules together.

What is a Condensation Reaction?

A reaction where two molecules combine to form a larger molecule, releasing water as a byproduct.

What are the differences between DNA and RNA?

DNA is double-stranded, contains deoxyribose sugar, and stores genetic information; RNA is single-stranded, contains ribose sugar, and is involved in protein synthesis.

What are the Four Levels of Structure for Proteins?

1. Primary structure: sequence of amino acids. 2. Secondary structure: folding into alpha helices or beta sheets. 3. Tertiary structure: overall 3D shape. 4. Quaternary structure: assembly of multiple polypeptides.

What factors affect the initial folding and stability of proteins?

Interactions between amino acids, environmental conditions (pH, temperature), and the presence of chaperone proteins.

What does denature mean?

The process by which a protein loses its native structure and function due to external stressors like heat or pH changes.

What category of molecule are DNA and RNA?

Nucleic acids.

What are some differences between Prokaryotic and Eukaryotic Cells?

Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have a nucleus and organelles.

What are some differences between Plant and Animal Cells?

Plant cells have a cell wall, chloroplasts, and large central vacuoles, while animal cells do not.

What are some arguments supporting the bacterial origin of mitochondria and chloroplasts?

Both organelles have their own DNA, double membranes, and similarities to bacterial structures.

Prokaryotic cells

Cells that lack a nucleus and membrane-bound organelles, typically smaller and simpler than eukaryotic cells.

Eukaryotic cells

Cells that have a nucleus and membrane-bound organelles, larger and more complex than prokaryotic cells.

Plant cells

Eukaryotic cells that contain chloroplasts, a cell wall, and large central vacuoles.

Animal cells

Eukaryotic cells that lack a cell wall and chloroplasts, typically smaller than plant cells.

Nucleus

The membrane-bound organelle that contains the cell's genetic material (DNA) and controls cellular activities.

Ribosomes

Molecular machines that synthesize proteins by translating messenger RNA.

Endoplasmic Reticulum (ER)

A network of membranes involved in protein and lipid synthesis; can be rough (with ribosomes) or smooth (without ribosomes).

Golgi apparatus

An organelle that modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

Lysosomes

Membrane-bound organelles that contain enzymes for digesting macromolecules and recycling cellular components.

Vacuoles

Storage organelles that can hold various substances, including nutrients, waste products, and water.

Peroxisomes

Organelles that contain enzymes for breaking down fatty acids and detoxifying harmful substances.

Mitochondria

Organelles known as the powerhouses of the cell, where ATP is produced through cellular respiration.

Chloroplasts

Organelles found in plant cells that conduct photosynthesis, converting light energy into chemical energy.

Plasmodesmata

Channels between plant cells that allow for transport and communication.

Intercellular junctions in animal cells

Structures that connect adjacent cells, including tight junctions, desmosomes, and gap junctions.

Phospholipid

A lipid molecule that forms the bilayer of cell membranes, consisting of a hydrophilic head and two hydrophobic tails.

Glycoprotein

A protein with carbohydrate chains attached, playing roles in cell recognition and signaling.

Glycolipid

A lipid with carbohydrate chains attached, contributing to cell membrane structure and recognition.

Transmembrane proteins

Proteins that span the entire membrane and are involved in transport and signaling.

Lipid-anchored proteins

Proteins that are covalently attached to lipids in the membrane, anchoring them in place.

Peripheral proteins

Proteins that are loosely attached to the membrane surface and are involved in signaling and maintaining the cell's shape.

Passive transport

The movement of substances across a cell membrane without the use of energy, typically down their concentration gradient.

Active transport

The movement of substances against their concentration gradient, requiring energy and specific transport proteins.

Endocytosis

The process by which cells take in substances by engulfing them in a membrane.

Exocytosis

The process by which cells expel materials in vesicles that fuse with the plasma membrane.

Diffusion

The passive movement of molecules from an area of higher concentration to an area of lower concentration.

Facilitated diffusion

The process of passive transport of molecules across a membrane via specific transport proteins.

Osmosis

The diffusion of water molecules across a semipermeable membrane from a region of lower solute concentration to higher concentration.

Hypertonic solution

A solution with a higher concentration of solutes compared to another solution, causing cells to lose water.

Hypotonic solution

A solution with a lower concentration of solutes compared to another solution, causing cells to gain water.

Isotonic solution

A solution with an equal concentration of solutes compared to another solution, resulting in no net movement of water.

Plasmolysis

The process in which cells lose water in a hypertonic solution, causing the cell membrane to pull away from the cell wall.

What are the stages in mitosis?

The stages of mitosis are prophase, metaphase, anaphase, and telophase.

What is the purpose of mitosis?

The purpose of mitosis is to produce two genetically identical daughter cells for growth, repair, and asexual reproduction.

What is the final outcome or product(s) of mitosis?

The final outcome of mitosis is two diploid daughter cells, each with the same number of chromosomes as the original cell.

What type of cells do these divisions occur in?

Mitosis occurs in somatic (body) cells.

How many chromosomes are present in the G1 stage of interphase in a human cell?

In the G1 stage of interphase, a human cell has 46 chromosomes.

How many chromosomes are present at metaphase in a human cell?

At metaphase, a human cell also has 46 chromosomes.

What is the difference between a chromosome and a chromatid?

A chromosome is a single DNA molecule, while a chromatid is one half of a duplicated chromosome, joined at the centromere.

What are the major differences between mitosis and meiosis?

Mitosis results in two identical diploid cells, while meiosis results in four genetically diverse haploid cells.

What is the purpose of meiosis?

The purpose of meiosis is to produce gametes (sperm and eggs) for sexual reproduction.

What is the final outcome of meiosis?

The final outcome of meiosis is four haploid gametes, each with half the number of chromosomes.

What type of cells does meiosis occur in?

Meiosis occurs in germ cells (sex cells).

How many chromosomes and chromatids are present in a cell in prophase I?

In prophase I, a human cell has 46 chromosomes and 92 chromatids.

How many chromosomes and chromatids are present after telophase I?

After telophase I, there are 23 chromosomes and 46 chromatids in each daughter cell.

How many chromosomes and chromatids are present after telophase II?

After telophase II, there are 23 chromosomes and 23 chromatids in each daughter cell.

What are the benefits of exchanging genetic material between homologous chromosomes?

Exchanging genetic material increases genetic diversity and can enhance adaptability of the population.

Define Nondisjunction.

Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate properly during cell division.

Define Aneuploidy.

Aneuploidy is a condition in which there is an abnormal number of chromosomes in a cell.

Define Polyploidy.

Polyploidy is a condition in which a cell has more than two complete sets of chromosomes.

What type of disorders are examples of nondisjunction in humans?

Examples include Down syndrome (trisomy 21) and Turner syndrome (monosomy X).

Give examples of genetic disorders that are 'large scale'.

Examples include Down syndrome, Klinefelter syndrome, and Turner syndrome.