Chapter 1-5 General Biology Review Flashcards

Comprehensive practice flashcards covering scientific method, chemistry of life, macromolecules, cell structure, and organelle functions based on lecture notes.

What is the primary difference between a scientific hypothesis and a scientific theory?

A hypothesis is a suggested explanation for an event that can be tested, whereas a theory is a tested and confirmed explanation for observations or phenomena.

How do inductive reasoning and deductive reasoning differ in scientific thinking?

Inductive reasoning uses related observations to arrive at a general conclusion, whereas deductive reasoning starts with a specific question or problem and tests a potential answer or solution.

What is the difference between an independent variable and a dependent variable in an experiment?

The independent variable is the factor purposely changed by the researcher (the cause), whereas the dependent variable is the outcome measured and recorded (the effect).

What is the distinction between controlled variables and a control in an experimental setup?

Controlled variables are all the conditions kept identical across groups, whereas the control is the untreated group used as a comparison standard.

What is the main objective of basic science compared to applied science?

Basic science seeks to expand knowledge regardless of short-term application, while applied science aims to use scientific knowledge to solve real-world problems.

What is the purpose of the peer-review process for scientific papers and grant proposals?

Peer review ensures that scientific research is original, significant, logical, and thorough prior to publication or funding.

What sections make up the IMRaD format of a scientific paper?

Introduction, Materials and Methods, Results, and Discussion.

What eight key characteristics serve to define all living organisms?

Order, sensitivity or response to the environment, reproduction, adaptation, growth and development, regulation/homeostasis, energy processing, and evolution.

Why are viruses not considered living organisms by scientists?

Viruses are not made of cells and must invade and hijack a living host cell's reproductive mechanisms to reproduce.

Which domain of life in this phylogenetic tree contains multicellular organisms such as animals, fungi, and plants?

Eukarya.

Which four elements make up 96% of the body weight of living organisms?

Oxygen (O), carbon (C), hydrogen (H), and nitrogen (N).

What are the three main subatomic particles and their respective electrical charges?

Protons (positive charge), neutrons (neutral charge), and electrons (negative charge).

What is the difference between a cation and an anion?

A cation is a positively charged ion that lost one or more electrons, while an anion is a negatively charged ion that gained one or more electrons.

How do ionic bonds and covalent bonds differ?

Ionic bonds form between oppositely charged ions, whereas covalent bonds form when atoms share pairs of electrons.

What defines an acidic solution versus an alkaline solution on the pH scale?

An acidic solution has a higher concentration of $H^+$ than $OH^-$ ($[H^+] > [OH^-]$) with a pH below 7; an alkaline solution has a higher concentration of $OH^-$ than $H^+$ ($[H^+] < [OH^-]$) with a pH above 7.

What is the function of buffers in living organisms?

Buffers readily absorb excess $H^+$ or $OH^-$ to keep the body's pH within the narrow, steady range required for survival.

What three parts compose a single nucleotide unit in DNA?

A 5-carbon deoxyribose sugar, a nitrogenous base (A, T, C, or G), and a phosphate group.

What chemical bonds join opposing nitrogenous bases together in the double-stranded DNA molecule shown in the diagram?

Hydrogen bonds.

What are Chargaff's Rules regarding DNA base composition?

In DNA, the amount of adenine equals thymine ($A = T$) and the amount of cytosine equals guanine ($C = G$).

What are three key structural differences between RNA and DNA?

RNA is usually single-stranded, contains ribose sugar instead of deoxyribose, and uses uracil (U) instead of thymine (T).

What monomer units compose proteins, and what covalent bonds link them together?

Amino acids linked together by peptide bonds.

What four levels of protein structure are represented in this diagram?

Primary (amino acid sequence), Secondary (coils/folds like α-helix and β-pleated sheet), Tertiary (unique 3D folding), and Quaternary (interaction of multiple polypeptide chains).

What occurs when a protein undergoes denaturation?

Harsh conditions like extreme temperatures or pH disrupt hydrogen and ionic bonds, causing the 3D structure to fall apart and lose biological function.

What two monosaccharides combine via a glycosidic bond to form sucrose as shown in the diagram?

Glucose and fructose.

What polysaccharides serve as energy storage in animals and plants, respectively?

Animals store energy as glycogen, while plants store energy as starch.

What structural feature makes lipids unique compared to carbohydrates, proteins, and nucleic acids?

Lipids are non-polar hydrophobic hydrocarbons that are non-polymeric (not composed of repeating monomer subunits).

How are phospholipid molecules arranged in the plasma membrane bilayer shown in the diagram?

Hydrophilic polar heads face outward toward the aqueous solution, while hydrophobic non-polar fatty acid tails point inward toward the center of the bilayer.

What are the three main principles of the cell theory?

1. All organisms are made of cells. 2. Cells are the basic units of structure and function in living things. 3. All cells arise from preexisting cells.

What four structural components are shared by all prokaryotic and eukaryotic cells?

Plasma membrane, cytoplasm (cytosol), DNA, and ribosomes.

Where is the chromosomal DNA located in prokaryotes, as illustrated in this bacterial cell diagram?

In a region called the nucleoid.

What organelles are found in animal cells but not in plant cells?

Centrosomes and lysosomes.

What organelles and structures are present in plant cells but absent in animal cells?

A cell wall (made of cellulose), chloroplasts, and a large central vacuole.

How do plant cells respond when placed in hypertonic, isotonic, and hypotonic solutions as depicted in the diagram?

In a hypertonic solution, water leaves causing plasmolysis; in an isotonic solution, cells become flaccid; in a hypotonic solution, water enters creating turgor pressure (turgid).

What are the distinct functions of the Rough ER and Smooth ER?

Rough ER has attached ribosomes and synthesizes proteins, whereas Smooth ER lacks ribosomes and synthesizes lipids such as oils, phospholipids, and steroids.

What is the function of the Golgi complex in a eukaryotic cell?

It modifies synthesized molecules and packages materials into vesicles to deliver them to other parts of the cell.

What is the primary function of mitochondria in eukaryotic cells?

Mitochondria process molecules to produce energy in the form of ATP.