Science and Life, Chemistry, Cellular Reproduction

Flashcards covering key concepts from lecture notes on science, the scientific method, basic chemistry of life, cellular structures, energy transformations, genetic information, DNA replication, gene expression, cell division (mitosis and meiosis), and human genetics in health contexts.

What is the primary difference between a scientific approach and other approaches to understanding the world?

A scientific approach involves testing possible solutions to problems, distinguished by how knowledge is acquired rather than just accumulating facts.

What does the Latin term 'scientia' mean, from which the word 'science' is derived?

To have knowledge or to know.

What is the scientific method?

A way of gaining information about the world by forming possible solutions to questions followed by rigorous testing to determine if the proposed solutions are valid.

What are the fundamental assumptions scientists make when using the scientific method?

There are specific causes for events, causes can be identified, general rules can describe nature, repeated events have the same cause, and what one perceives can be perceived by others, and fundamental rules apply universally.

When is a cause-and-effect relationship said to exist?

When an event occurs as the result of a known reason, and the first event always occurs before and initiates the second event.

What is the core expectation for scientific information?

It undergoes constant reevaluation, criticism, and modification; scientists discard or change ideas if new evidence is not supportive.

What is 'observation' in a scientific context?

Careful, thoughtful recognition of an event using senses or extensions of senses, not just casual notice.

What is 'empirical evidence'?

Information gained by direct observation of an event, capable of being verified or disproved by further observation.

Why can phenomena like 'miracles' not be verified by science?

If an event only occurs once or cannot be repeated in an artificial situation, it is impossible to use the scientific method to gain further information about it.

What makes a good scientific question?

It must be answerable, and the way it is asked determines how one approaches answering it.

What is a 'hypothesis'?

A possible answer to a question or an explanation of an observation that is testable and accounts for all known information.

What distinguishes a hypothesis from a random guess or rumor?

A hypothesis is an educated guess based on observations and information from knowledgeable sources, not just unsubstantiated information.

What is the goal of scientists regarding hypotheses?

Scientists try to disprove a hypothesis, not prove they are right.

What is a 'controlled experiment'?

An experiment that allows scientists to compare two situations identical in all but one respect, with a control group and an experimental group differing only by a single variable.

What is a 'control group' in a controlled experiment?

The situation used as the basis for comparison, where the variable is controlled.

What is an 'experimental group' in a controlled experiment?

The group in a controlled experiment where the single factor (variable) is allowed to be different.

What is the 'variable' in a controlled experiment?

The single factor allowed to be different in the experimental group but controlled in the other group.

Why is it important for an experiment to be repeated many times?

To be validated, as scientists encourage challenges to their work and admit no experiment is perfect.

What do 'accurate data' refer to in experiments?

Experimental results that conform to the facts and deviate only slightly or within acceptable limits from a standard.

What do 'precise data' refer to in experiments?

Exact data, where experimental research results occur the same, time after time.

What is a 'theory' in science?

A plausible, scientifically acceptable generalization that is the result of years of questioning, experimentation, and data collection.

How does a scientific theory differ from common usage of the word 'theory'?

A scientific theory is a broad, well-supported generalization, while common usage often refers to an unsubstantiated claim or opinion.

What is an example of a biological theory?

The germ theory of disease, stating that infectious diseases are caused by transmittable microorganisms.

What happens if new evidence doesn't support a theory?

A theory may be found to be incorrect or to need modification.

What is a 'scientific law'?

A uniform or constant rule of nature that describes how something happens, even more general than theories.

What is an example of a scientific law?

The biogenetic law, stating that all living things come from preexisting living things.

What are the intellectual standards of thinking necessary for successful scientific investigations?

Clarity, accuracy, precision, relevance, logic, and exploration of depth and breadth, while avoiding bias.

What is 'critical thinking'?

Reasonable, reflective thinking that focuses on deciding what to do or believe, helping to arrive at valid and reliable results.

What is 'induction' or 'inductive reasoning'?

The process of developing general principles from the examination of many sets of specific facts.

What is 'deduction' or 'deductive reasoning'?

The process of using general principles to predict the specific facts of a situation.

What is 'peer review' in science?

The communication and examination of scientific research, thoughts, and opinions by other scientists interested in the same questions, often through publication in scientific journals.

What is the typical attitude of a scientist ('healthy skeptic')?

Insistence on ample supporting evidence from numerous studies rather than easy acceptance of strongly stated opinions, clearly distinguishing fact from opinion.

Why is honesty a strong ethic in science?

Science conducted openly among peers tends to reduce dishonesty, and the community severely penalizes shoddy work, falsified data, or stolen ideas.

What is 'clinical pharmacology'?

A formal scientific discipline concerned with the study of drugs and their interactions with living beings, focusing on medications used in human patients.

What is a 'drug'?

Any chemical that affects biochemical processes, also known as medications, that alter chemicals or chemical reactions in living systems.

What properties would the 'perfect' medication have?

Safety, effectiveness, selectivity, predictability, reversibility, easy administration, no drug interactions, stability, and low cost.

What is 'preclinical testing' in drug development?

Testing involving the use of animals to determine whether a drug performs as expected.

What are the four phases of 'clinical testing' in drug development?

Phase I (healthy volunteers/patients for metabolism/side effects), Phase II and III (unhealthy individuals for efficacy, safety, dose), and Phase IV (released to public on restricted basis with physician/manufacturer monitoring).

What is 'pseudoscience'?

Information that takes on the flavor of science but is not supportable as valid or reliable, often intended to confuse or mislead.

What are the limitations of science in answering questions?

It can only be applied to questions with a factual basis; it cannot answer questions concerning morals, value judgments, social issues, or attitudes.

Why is science not infallible?

Science is in a constant state of development, mistakes are made, and understanding changes as new information is gathered and old, mistaken ideas are clarified.

What happened with William Harvey's observations about blood flow?

He made careful observations demonstrating that blood in surface veins flowed in only one direction, blocking flow in two places and observing the middle section didn't fill.

What can genetic engineers do with small organisms?

Alter their chemical code system to produce new drugs such as antibiotics, hormones, and enzymes.

How did Louis Pasteur's theoretical work lead to practical applications?

His theory about microorganisms causing diseases and decay led to rabies vaccinations and pasteurization for food preservation.

What is the distinction between a scientist and a nonscientist regarding assumptions?

A scientist continually challenges and tests principles and laws to determine cause-and-effect, while a nonscientist may not see this as important.

Which fields are generally considered sciences?

Physics, chemistry, geology, and biology.

Which fields are generally not considered sciences, and why?

Art, literature, theology, and philosophy, as they are concerned with beauty, human emotion, and speculative thought rather than facts and verifiable laws.

Why are economics, anthropology, and sociology not considered true sciences?

Many of their generalizations cannot be tested by repeated experimentation; they don't show a significantly high degree of cause-and-effect or have poor predictive value.

What are the five basic characteristics of living things?

Metabolic processes, generative processes, responsive processes, control processes, and unique structural organization.

What are 'metabolic processes' (metabolism)?

The total of all chemical reactions taking place within an organism, including nutrient uptake, nutrient processing, and waste elimination.

What are 'generative processes'?

Reactions that result in an increase in the size of an individual organism (growth) or an increase in the number of individuals in a population (reproduction).

What is 'reproduction' in living things?

One of the most important life functions, the only way living things can perpetuate themselves.

What are 'responsive processes'?

A group of characteristics involved in an organism's ability to react to external and internal changes in its environment, including irritability, individual adaptation, and population adaptation (evolution).

What is 'irritability'?

An individual's rapid response to a stimulus, such as a knee-jerk reflex or a cell moving toward/away from light, heat, or chemicals.

What is 'individual adaptation'?

A slower individual response requiring activation of genetic information, like increasing red blood cells at high altitude.

What is 'population adaptation' (evolution)?

A slow change in the genetic makeup of a population of organisms over many generations, enabling better survival.

What are 'control processes'?

Mechanisms that ensure an organism will carry out all metabolic activities in the proper sequence (coordination) and at the proper rate (regulation).

What are 'enzymes' in the context of control processes?

Molecules produced by organisms that increase and control the rate of life's chemical reactions, and regulate the amount of nutrients processed.

What is the basic structural organization shared by all living things?

All living things are made up of complex, structural units called cells.

What are the common features of all cells?

An outer cell or plasma membrane, fluid-like cytoplasm, genetic material (DNA), and a chemical mechanism for using energy (ATP).

What are 'prokaryotic cells'?

Cells lacking a cellular nucleus, like bacteria and archaea.

What are 'eukaryotic cells'?

Cells with a cellular nucleus, like human liver cells and organisms in the kingdoms Protista, Fungi, Plantae, and Animalia.

What is 'anatomy'?

The study of the structure of living things, which are composed of matter.

What is 'matter'?

Anything that has mass and takes up space (volume).

How does 'mass' differ from 'weight'?

Mass refers to an amount of matter, while weight refers to the amount of force (push or pull) with which an object is attracted by gravity.

What is 'physiology'?

The scientific study of living processes, activities, and functions, which require the use of energy.

What is 'energy'?

The ability to do work or cause things to move.

What is 'kinetic energy'?

Energy of motion, like a fish swimming or a sugar molecule breaking down.

What is 'potential energy'?

Energy that is not yet doing work; stored energy, like chemical energy in matter.

When does potential energy increase?

When things experiencing a repelling force are pushed together (like a compressed spring) or when things that attract each other are pulled apart (like a stretched rubber band).

What is the 'Law of Conservation of Energy' (First Law of Thermodynamics)?

Energy is never created or destroyed; it can only be converted from one form to another, but the total energy remains constant.

What are the five forms of energy?

Mechanical, nuclear, electrical, radiant, and chemical.

What is 'mechanical energy'?

Energy associated with machines or things in motion.

What is 'nuclear energy'?

Energy from reactions involving the innermost part of matter, the nucleus.

What is 'electrical energy'?

The flow of charged particles, used by all organisms as part of their metabolism (e.g., nervous systems).

What is 'radiant energy'?

Energy most familiar as heat and visible light, but also includes X-radiation and microwaves.

What is 'chemical energy'?

A kind of internal potential energy stored in matter that can be released as kinetic energy when chemicals change form (e.g., chemical bond energy).

What is the 'kinetic molecular theory'?

The theory stating that all matter is made up of tiny particles that are in constant motion.

What are 'atoms'?

The smallest units of matter that can exist alone, fundamental units from which all matter is made.

What are 'elements'?

Fundamental chemical substances made up of only one kind of atom.

What are the main elements comprising living things?

C, H, O, P, K, I, N, S, Ca, Fe, and Mg (CHOPKINS CaFé, Mighty good!).

What is a 'compound'?

A chemical substance made up of atoms of two or more elements combined in a specific ratio and arrangement.

What is a 'molecule'?

A single particle of a substance composed of two or more atoms attached to one another by attractive forces called chemical bonds, retaining the characteristics of that substance.

What does the chemical formula H2O tell us about water?

It contains two atoms of hydrogen and one atom of oxygen.

What are 'diatomic molecules'?

Molecules formed when two atoms of the same element bond together, like H2, O2, N2.

What are the three states of matter, and how do their molecules differ?

Solid (packed, vibrate in place, fixed distances), liquid (attracted, slightly farther apart, slide past each other), gas (attraction overcome by speed, collisions push them farther apart).

What is 'hardness' of a solid?

The resistance of a solid to forces that tend to push its molecules further apart.

What is 'vapor'?

The gaseous form of a substance that is usually in the liquid state (e.g., water vapor).

What are the three major particles an atom is constructed of?

Neutrons (neutral, in nucleus), protons (positive, in nucleus), and electrons (negative, surrounding nucleus).

Where is the weight or mass of an atom concentrated?

In the nucleus (protons and neutrons).

What determines the overall size of an atom?

The number of electrons.

When is an atom's charge neutral?

If the number of positively charged protons equals the number of negatively charged electrons.

What determines the identity of an element?

The number of protons; all atoms of the same element have the same number of protons.

What is the 'atomic number' of an element?

The number of protons in an atom of that element.

What is an 'atomic mass unit' (AMU)?

A unit of mass, where one proton or neutron is said to have a mass of one AMU.

What is an 'isotope'?

Each atom of the same element with a different number of neutrons.

What is the 'atomic weight' of an element?

An average of all the isotopes present in their normal proportions.

What is the 'mass number'?

The sum of the number of protons and neutrons in the nucleus of an atom, used to identify isotopes.

What are 'radioactive isotopes' (radionuclides)?

Unstable isotopes that disintegrate, releasing energy and fast-moving subatomic particles.

What are the three most common things released from the nucleus of disintegrating atoms?

Beta particles (electrons), alpha particles (two protons, two neutrons), and gamma radiation (most penetrating).