AP Biology Ultimate Guide (copy)

What are elements in the context of chemistry of life?

Substances that cannot be broken down into simpler substances by chemical means.

Which four elements are primarily used to build biological molecules?

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

What are trace elements?

Elements required by an organism only in very small quantities, such as iron (Fe), iodine (I), and copper (Cu).

What are subatomic particles in atoms?

Protons (positively charged), neutrons (uncharged), and electrons (negatively charged).

What is a compound?

A substance that consists of two or more elements held together by chemical bonds.

What type of bond is formed when electrons are transferred from one atom to another?

Ionic bond.

What type of bond involves the sharing of electrons?

Covalent bond.

What are the properties of water that result from hydrogen bonding?

Cohesion, adhesion, surface tension, high heat capacity, and expansion on freezing.

What is pH a measure of?

The acidity or alkalinity of a solution based on the concentration of hydrogen ions (H+).

What is the formula for calculating solute potential of a solution?

Ψs = -iCRT where i is the ionization constant, C is the molar concentration, R is the pressure constant, and T is the temperature in Kelvin.

What is the primary function of carbohydrates?

To serve as an energy source for cells.

What are proteins made of?

Amino acids, which contain carbon, hydrogen, oxygen, and nitrogen atoms.

What is the basic structure of a nucleic acid?

Nucleotides, which consist of a five-carbon sugar, a phosphate group, and a nitrogenous base.

What are the main stages of cellular respiration?

Glycolysis, formation of acetyl-CoA, the Krebs (citric acid) cycle, and oxidative phosphorylation.

What process involves the splitting of glucose into pyruvate?

Glycolysis.

What is the purpose of meiosis?

The production of gametes (sex cells).

What is the difference between haploid and diploid cells?

Haploid cells have one set of chromosomes (n), while diploid cells have two sets (2n).

What are the three principles of Mendelian genetics?

The Law of Dominance, the Law of Segregation, and the Law of Independent Assortment.

What is a Barr body?

An X chromosome that is condensed and inactivated in female cells.

What is natural selection?

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

What factors influence population growth?

Births, deaths, immigration, and emigration.

What is ecological succession?

The predictable procession of plant communities over time, which includes primary succession and secondary succession.

What is the greenhouse effect?

The warming of Earth's surface due to trapped heat by greenhouse gases.

What does the term 'allele' refer to?

Different versions of a gene that may produce different traits.

What are the characteristics of living organisms?

Living organisms exhibit organization, metabolism, growth, reproduction, responsiveness, and adaptation.

What is the significance of water in biological systems?

Water is a solvent, a transport medium, and is essential for biochemical reactions; its unique properties are crucial for life.

How are enzymes important to biochemical reactions?

Enzymes act as catalysts that speed up chemical reactions in cells by lowering the activation energy.

What is the role of lipids in biological membranes?

Lipids form the bilayer structure of cell membranes, providing barrier functions and aiding in cell signaling.

What is the difference between RNA and DNA?

RNA is single-stranded, contains uracil instead of thymine, and is involved in protein synthesis, whereas DNA is double-stranded and stores genetic information.

How does the process of photosynthesis work?

Photosynthesis converts light energy into chemical energy by using sunlight to convert carbon dioxide and water into glucose and oxygen.

What are gametes and their function in reproduction?

Gametes are haploid reproductive cells (sperm and egg) that combine during fertilization to form a diploid zygote.

What are the key factors that influence climate?

Temperature, precipitation, humidity, wind patterns, and geographical features all contribute to the local and global climate systems.

What is biodiversity and why is it important?

Biodiversity refers to the variety of life in a particular habitat or ecosystem; it is essential for ecosystem resilience and stability.

What is the difference between primary and secondary succession?

Primary succession occurs in lifeless areas where soil is not yet formed, while secondary succession occurs in areas where an ecosystem has been disturbed but soil remains.

What is the role of ATP in cellular processes?

ATP (adenosine triphosphate) serves as the primary energy currency of cells, providing energy for various metabolic processes, including biosynthesis, transport, and mechanical work.

Explain the significance of the double helix structure of DNA in relation to its function.

The double helix structure of DNA enables efficient storage of genetic information and facilitates replication and transcription through complementary base pairing, ensuring accurate transmission of genetic information.

What are the implications of enzyme saturation on reaction rates?

Enzyme saturation occurs when all active sites of an enzyme are occupied by substrate, leading to a maximum reaction rate; further increases in substrate concentration do not increase the rate, indicating the need for more enzyme to enhance reaction speed.

How does natural selection drive evolution? Provide an example.

Natural selection drives evolution by favoring individuals with advantageous traits that enhance survival and reproduction in a given environment; for example, the evolution of antibiotic resistance in bacteria demonstrates how selected traits become more prevalent in populations over time.

What is the difference between allopatric and sympatric speciation?

Allopatric speciation occurs when populations are geographically isolated, leading to reproductive isolation and divergence, while sympatric speciation happens within the same geographic area due to behavioral changes, polyploidy, or other mechanisms.

Discuss the importance of feedback mechanisms in maintaining homeostasis.

Feedback mechanisms, both positive and negative, are crucial for maintaining homeostasis in organisms; negative feedback counteracts changes to restore stability (e.g., temperature regulation), while positive feedback amplifies processes (e.g., labor contractions during childbirth).

Explain how the fluid mosaic model describes cell membrane structure and function.

The fluid mosaic model depicts the cell membrane as a flexible layer composed of lipid molecules with embedded proteins; this arrangement allows for dynamic movement, transport of materials, and communication between cells.

How do organisms respond to environmental changes through adaptations?

Organisms develop adaptations—traits that enhance fitness in their environment—through natural selection, such as physiological changes in response to temperature or behavior adjustments to available resources.

What is the significance of the greenhouse effect and its impact on global warming?

The greenhouse effect is vital for maintaining Earth's temperature; however, increased greenhouse gas emissions enhance this effect, leading to global warming, which disrupts ecosystems, weather patterns, and sea levels.

Describe the role of the Krebs cycle in cellular respiration. What are its main outputs?

The Krebs cycle, also known as the citric acid cycle, plays a critical role in cellular respiration by oxidizing acetyl-CoA to produce NADH and FADH2 for the electron transport chain, with main outputs including carbon dioxide, ATP, and reduced electron carriers.