Biology: Life Processes, Characteristics of Living Things, and Origin of Life

A set of Question-and-Answer flashcards covering key terms and concepts from Page 1 and Page 2 notes on life, its processes, and theories about the origin of life.

What is cellular respiration?

A process by which energy is released by the breakdown of food substances to do work in living organisms.

What is metabolism?

Sum of all chemical processes and energy changes occurring inside the body.

What is nutrition?

Process by which organisms acquire food to survive, grow, and reproduce; energy is obtained indirectly from the sun by ingesting food.

What is photosynthesis?

Process by which organisms use light energy from the sun to synthesize food, storing energy in chemical bonds.

What is excretion?

The process of removing waste from the body (CO2, H2O, mineral salts, nitrogenous wastes).

Name organs involved in elimination.

Skin, lungs, kidneys, large intestine, and urinary bladder.

What is homeostasis?

Maintenance of the body's internal environment in a stable state.

What is locomotion or motility?

Movement from one place to another, often using locomotory organs.

What is sensibility (irritability)?

The ability of an organism to respond appropriately to a stimulus.

What is evolution?

Changes in the characteristics of a group of organisms (a species) over time.

What is development?

Defined stages in the life cycle of a living thing from fertilization to death.

What is the first characteristic shared by living systems?

Gathering and using energy.

What is the second characteristic shared by living systems?

Maintaining internal balance.

What is the third characteristic shared by living systems?

Responding, adapting, and evolving.

What is the fourth characteristic shared by living systems?

Reproducing and continuing life.

What is tropism?

Reaction of an organism to stimuli (growth or movement toward or away from a stimulus).

What are stimuli?

External factors such as light, sound, temperature, pressure, food sources, or chemical substances.

What is growth?

Increase in size and volume, including conversion of food into body mass.

What is accretion?

Growth by external addition of substances, typically used for nonliving things.

What is intussusception in this context?

Process by which living things exhibit growth from within the cells.

What is reproduction?

Process by which genetic information is passed from one generation to the next.

What carries inherited genetic information during reproduction?

DNA.

What are sexual and asexual reproduction?

Sexual reproduction is the union of cells from two parents; asexual reproduction makes copies of itself.

What are the three domains of life?

Bacteria, Archaea, and Eukarya.

What does abiogenesis (spontaneous generation) mean?

The idea that life originates from nonliving matter.

What is biogenesis?

The belief that life originates from preexisting life.

What is creationism?

The belief that life forms were created through supernatural power rather than natural means.

Which scientists are commonly associated with origin-of-life experiments (17th–19th centuries)?

Redi, Needham, Spallanzani, and Pasteur.

What did Redi's experiment demonstrate?

Life does not arise from nonliving matter; it comes from existing living matter.

What did Needham's experiment claim?

Boiled broths appeared to generate microorganisms, suggesting spontaneous generation.

What did Spallanzani's experiment show?

Excluding air in sealed flasks prevented spontaneous generation, supporting biogenesis.

What did Pasteur's experiment demonstrate?

Air exposure in a swan-neck flask did not lead to microbial growth; life comes from existing organisms.

What is the Miller–Urey idea?

The suggestion that lightning reactions could have helped form key building blocks of life.

What is panspermia?

The idea that organic molecules may have arrived on Earth via meteor or cosmic dust, seeding life.