Human Biology: Concepts and Current Issues Study Guide

This set of flashcards covers key concepts from Human Biology: Concepts and Current Issues, focusing on essential definitions, processes, and distinctions to aid in exam preparation.

What is the difference between living and non-living things in terms of energy acquisition?

Living things acquire energy and raw materials from the environment, while non-living things cannot.

Define homeostasis.

Homeostasis is a state of dynamic equilibrium characterized by relative constancy of the internal environment in living organisms.

List some traits that distinguish humans from other species.

Bipedalism, opposable thumbs, large brain, and capacity for complex language.

What is a hypothesis?

A hypothesis is a tentative statement about the natural world that can lead to testable predictions.

What is the role of scientists in decision-making regarding economic and social issues?

Scientists provide information about the natural world to help make informed choices but do not have superior abilities to answer social or ethical dilemmas.

What characterizes protons and neutrons?

Protons and neutrons have about equal masses, while protons and electrons have charges; electrons have very little mass.

How do hydrogen atoms interact in the context of water molecules?

Each hydrogen atom's one electron completes the orbital of the other.

What types of molecules can form hydrogen bonds with water?

Polar and charged molecules can form hydrogen bonds with water.

Compare covalent bonds and ionic bonds.

Covalent bonds involve shared electrons and are generally stronger, while ionic bonds are formed by attractive forces between oppositely-charged ions.

Define potential energy and kinetic energy.

Potential energy is stored energy that can be used, while kinetic energy is working energy actively facilitating processes.

Differentiate saturated fats from unsaturated fats.

Saturated fats have all possible hydrogens attached to carbons and are solid at room temperature, while unsaturated fats are missing some hydrogens and tend to be liquid.

What is the role of cholesterol in the body?

Cholesterol is a component of cell membranes and is necessary for synthesizing reproductive hormones.

How is a protein's shape determined?

A protein's shape is influenced by weak chemical bonds between amino acids.

What role do enzymes play in chemical reactions?

Enzymes help chemical reactions occur quickly enough to sustain life.

How does ATP function in biological systems?

ATP acts like a rechargeable battery, temporarily storing energy for use in energy-requiring processes.

What limits the effectiveness of diffusion in cells?

Diffusion is only effective over very short distances, meaning cells must remain small.

What are the three main points of cell theory?

1. All living things are composed of cells and their products. 2. A single cell is the smallest unit of life. 3. All cells come from pre-existing cells.

How are phospholipids oriented in cell membranes?

Phospholipid heads face outwards towards water, while tails face inward towards each other.

What is passive transport and how does it work?

Passive transport moves substances from high to low concentration without energy.

What are the main functions of endocytosis and exocytosis?

Endocytosis brings materials into a cell, while exocytosis expels materials out.

Describe the sodium-potassium pump.

The sodium-potassium pump actively maintains a high concentration of potassium inside the cell and a low concentration of sodium.

What happens in hypertonic and hypotonic solutions?

In hypertonic solutions, cells shrink; in hypotonic solutions, cells swell or burst.

What are vesicles and their functions?

Vesicles are membrane-bound spheres that transport materials within the cell.

Name the four stages of ATP production from glucose.

1. Glycolysis, 2. Preparatory step, 3. Citric acid cycle, 4. Electron transport chain.

What does oxygen's role in cellular respiration entail?

Oxygen is required to facilitate the reactions of the electron transport system.

What are the advantages and disadvantages of complex multicellular organisms?

Advantages include size and environmental adaptation; disadvantages include specialization and higher resource needs.

Differentiate between epithelial, connective, muscle, and nervous tissues.

Epithelial tissues cover organs; connective tissues provide structural support; muscle tissues facilitate movement; nervous tissues transmit signals.

What are tight junctions and their function?

Tight junctions seal adjacent cell plasma membranes tightly, preventing passage between cells.

How do organs and organ systems differ?

An organ comprises two or more tissues for a specific function; an organ system includes multiple organs for broader functions.

List the major organ systems and their functions.

Integumentary (protection), skeletal (support), muscular (movement), circulatory (transport), lymphatic (filtering), respiratory (gas exchange), nervous (control), endocrine (hormones), digestive (nutrients), urinary (excretion), reproductive (reproduction).

What are negative and positive feedback mechanisms?

Negative feedback mechanisms counteract changes to maintain homeostasis; positive feedback amplifies changes.

What is the role of homeostasis in organisms?

Homeostasis maintains a stable internal environment, essential for efficient cell and tissue function.

What does the control center do in a feedback system?

The control center receives input from sensors and compares it to the set values, sending signals to effectors if discrepancies exist.

What roles do the kidneys perform?

The kidneys regulate water and electrolyte levels, excrete waste, and influence red blood cell production.

Describe the components of blood in terms of function.

Blood transports substances, regulates temperature, water volume, pH, and defends against infections.

What causes the formation of blood clots?

Damage to a blood vessel stimulates platelet formation and initiates the coagulation cascade.

Explain the difference between red and white blood cells.

Red blood cells transport oxygen; white blood cells are involved in immune responses.

What are the types of muscle tissues?

Skeletal, smooth, and cardiac muscle tissues.

Outline the general process of DNA replication.

DNA unwinds and unzips; complementary nucleotides are added to each strand, facilitated by DNA polymerase.

What is the process of transcription?

Transcription is the conversion of a DNA segment into a complementary RNA strand.