Scientific Laws

 

Scientific Laws, Hypotheses, and Theories

 

 

Scientific Theory versus “Just a theory” Layman’s term:

In layman’s terms, if something is said to be “just a theory,” it usually means that it is a mere guess, or is unproved. It might even lack credibility. But in scientific terms, a theory implies that something has been proven and is generally accepted as being true.

Scientific Meanings:

SCIENTIFIC LAW: This is a statement of fact meant to describe, in concise terms, an action or set of actions. It is generally accepted to be true and universal, and can sometimes be expressed in terms of a single mathematical equation. Scientific laws are similar to mathematical postulates. They don’t really need any complex external proofs; they are accepted at face value based upon the fact that they have always been observed to be true. Specifically, scientific laws must be simple, true, universal, and absolute. They represent the cornerstone of scientific discovery, because if a law ever did not apply, then all science based upon that law would collapse.  Some scientific laws, or laws of nature, include the law of gravity, Newton’s laws of motion, the laws of thermodynamics, Boyle’s law of gases, the law of conservation of mass and energy, and Hook’s law of elasticity.

HYPOTHESIS: This is an educated guess based upon observation. It is a rational explanation of a single event or phenomenon based upon what is observed, but which has not been proved. Most hypotheses can be supported or refuted by experimentation.

THEORY: A theory is more like a scientific law than a hypothesis. A theory is an explanation of a set of related observations or events based upon proven hypotheses and verified multiple times by detached groups of researchers. One scientist cannot create a theory; he can only create a hypothesis. Theories may be expanded or modified with further scientific evidence.

Development of a Simple Theory by the Scientific Method:

  • Start with an observation that evokes a question: Broth spoils when I leave it out for a couple of days. Why?
  • Using logic and previous knowledge, state a possible answer, called a Hypothesis: Tiny organisms floating in the air must fall into the broth and start reproducing.
  • Perform an experiment or Test: After boiling some broth, I divide it into two containers, one covered and one not covered. I place them on the table for two days and see if one spoils. Only the uncovered broth spoiled.
  • Then publish your findings in a peer-reviewed journal. Publication: “Only broth that is exposed to the air after two days tended to spoil. The covered specimen did not.”
  • Other scientists read about your experiment and try to duplicate it. Verification: Every scientist who tries your experiment comes up with the same results. So they try other methods to make sure your experiment was measuring what it was supposed to. Again, they get the same results every time.
  • In time, and if experiments continue to support your hypothesis, it becomes a Theory: Microorganisms from the air cause broth to spoil.

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Pzsol Moss Fern

Moss & Fern Puzzle Solution

Plants that lack tubes to carry food and water are called nonvascular plants. These plants are also known as bryophytes. Most bryophytes are terrestrial and live in moist environments. Water is required so that the sperm can swim to the egg during fertilization. Bryophytes do not produce seeds, but instead produce spores to reproduce. These plants exhibit alternation of generations in their life cycle. Because these plants lack vascular tissue, they are small in  height.

Moss is one example of a bryophyte that grows like a lush, green carpet. The dominant stage in the moss life cycle is the gametophyte. Root like rhizoids attach each gametophyte to the soil but do not absorb water. Both male and female gametophytes exist. The sporophyte generation is attached to the top of the gametophyte. Mosses are called pioneer plants because they often are the first plants to re-enter a barren area. Mosses also help prevent soil erosion. Sphagnum, or peat moss, is harvested and burned as fuel in some countries.

Liverworts and hornworts are nonvascular plants that also grow in moist, shady places. Liverworts have leaflike structures along a stem and lay close to the ground. Hornworts, like algae, have a single large chloroplast in each cell.

Ferns are simple, vascular plants that also lack seeds and reproduce by spores. Tree ferns are the largest ferns. Most ferns have an underground stem called a rhizomes. New leaves of ferns are tightly coiled and are called fiddleheads. Mature fern leaves are called fronds. Spores are produced on the underside of fern fronds.

 

Pzsol Nucleic Acid

Nucleic Acid Puzzle Solution

+ + + D + + + + + E A + + + + + + R E E + P + N + T + + + + S D + + + + E N + S + R + A + + R + + + + A E + + P I E + A + O + + + + + A + + + + C N L D + G D R C O M P L E M E N T A R Y I I + + O E E + F + + + + K + D S + L C M L N + R O M + R + + + C + + + I C A I + + E E D X Y G E + + I + + + + + T R + C + + H Y Y L U A + R + + + + + I Y O I + A + + H R O A D C + + + + + O P P + E P + R + + I P N O I T A L S N A R T H N L T + U + B + I D E N T I C A L + + U O + C I + + O + N E S O B I R + + + C + + S C U O + S E E + + + + + + + + L + + + Y P + N N E N + + + + + + + + E R + + T + + H + + O I + + + + + + + U N + + O + + + + A I + R + + + + + + S A B A S E + + + + T T + U + + + + + + + + + I + + + + + A + + E P + + + + + + + + N + + + + F T + + + + + + + + + + + + E + + + + + U O + + + + + + + + + + + + + + + + + M + + R + + + + N I L K N A R F + + + + + + + + K + + + + + + + + + N I T R O G E N + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + (Over,Down,Direction) ADENINE(11,1,SE) BASE(9,17,E) COMPLEMENTARY(1,5,E) CRICK(3,10,NE) CYTOSINE(15,13,SW) DEOXYRIBOSE(19,4,S) DNA(4,1,S) FORK(14,19,SE) FRANKLIN(8,22,W) GUANINE(1,8,S) HELICASE(17,8,NW) HYDROGEN(18,9,N) IDENTICAL(1,12,E) MUTATION(13,21,NE) NITROGEN(7,23,E) NUCLEOTIDE(17,14,NW) NUCLEUS(13,11,SW) PHOSPHATE(11,10,SE) POLYMERASE(20,10,N) PROOFREAD(2,2,S) PURINE(20,18,N) PYRIMIDINE(10,10,NE) REPLICATION(18,1,SW) RIBOSE(7,13,W) RNA(10,15,SW) TRANSCRIPTION(6,2,SE) TRANSLATION(11,11,W) URACIL(17,11,NW)

Pzsol Photosynthesis

 

 

Photosynthesis

Answer Key:

 

 

All organisms use energy to carry out their life functions. Some organisms obtain this energy from sunlight. The process by which this energy transfer takes place is called photosynthesis. Photosynthesis involves a biochemical pathway in which the product of one reaction is consumed in the next reaction. Autotrophs are organisms that carry on photosynthesis and includes plants and other organisms containing the green pigment chlorophyll. Autotrophs use carbon dioxide and water to make oxygen and the simple sugar glucose. The pigment chlorophyll absorbs light energy from the sun during the light reactions. Accessory pigments also in the chloroplast absorb other wavelengths of light that chlorophyll does not absorb. These accessory pigments are responsible for other colors we see in plants such as red, orange, and yellow. Chloroplasts are surrounded by a double membrane. Inside chloroplasts is a system of membranes arranged as stacks of flattened sacs called granum. Each sac in the stack is called a thylakoid. The thylakoids are surrounded by a solution called the stroma. The dark reactions of photosynthesis take place in the stroma. Most chloroplasts are found in the leaves of plants. The underside of a leaf contains openings called stomata where gases such as oxygen and carbon dioxide enter and leave. These openings or stomata are closed during the hottest times of the day by cells called guard cells.

Pzsol Taxonomy

 

Taxonomy

Answer Key:

 

1) taxonomy
2) linnaeus
3) aristotle
4) hierarchy
5) plants
6) animals
7) kingdom
8) phylum
9) division
10) class
11) order
12) family
13) genus
14) species
15) binomial
16) nomenclature
17) subspecies
18) variety
19) phylogeny
20) systematics
21) phylogenetic
22) tree
23) fossils
24) morphology
25) cladistics
26) derived
27) cladogram
28) arachaebacteria
29) eubacteria
30) protista
31) animalia
32) plantae
33) fungi
34) domain
35) eukarya
36) archae