Chapter 1 Flashcards
Define science
the study of the matter and move- ment of God’s physical creation
what is the study of soil ?
Pedology
what is a scientific law ?
scientific law is if a theory has never been proven false.
what does it mean to say that a hypothesis is falsifiable ?
There has to be some situation that, it it occurs, would prove the hypothesis to be false.
what is a experimental group ?
a experimental group are groups on which a test is performed.
what is a control group?
a group in which the independent variable is absent
what is a prototype?
model of a design or some part of a design that is used for testing
Define inference
conclusion based on reasoning from evidence
What do logicians call an “if /then” statement?
hypothetical proposition
Explain the difference between affirming the antecedent and denying the consequent.
- affirming the antecedent—If the antecedent is true, the consequent is true.
- denying the consequent—If the consequent is false, the antecedent is false.
what is the method of difference.
any difference in the outcome must be due to the difference in the independent variable
What is reproductibilty?
it’s the ability of others to confirm the results by testing the hypothesis under different conditions and using different experiments
What is repeatability?
it’s the ability of an experimenter to repeat his own results by performing the experiment multiple times under conditions as similar to the original as possible
What fallacy is assuming, without further evidence, that something caused what happened after it?
post hoc fallacy
Why is a hypothesis considered a model?
a hypothesis, if true, is a partial representation in word of how some part of the universe works
What two kinds of material make up soil?
organic material and mineral material
Besides holding large amounts of water, what job does humus do in soil?
enriches the soil
Name the top two layers of soil.
topsoil and subsoil
Name the process by which rocks are broken down into soil.
weathering
What determines the texture of soil?
the combination of different sizes of mineral particles
Give the functions of sand in soil?
allowing air and water into the soil
What is loam?
soil that contains a range of sand, silt, clay, and humus mixtures
What can color tell us about soil?
the amount of organic matter and types of minerals present
How do chemists express the degree of acidity or basicity of a substance?
PH-scale
List the three primary plant food elements.
nitrogen, phosphorus, and potassium
What form of phosphorus does fertilizer usually contain?
phosphates
What is the term for any bacteria that converts nitrogen into nitrogen compounds?
nitrogen-fixing bacteria
Which bacteria convert ammonia into nitrates?
Nitrifying bacteria
Which bacteria put nitrogen back into the air?
Denitrifying bacteria
List two ways that phosphorus benefits plants.
Any two of following:
- allowing cell division
- promoting plant maturation
- making fruits “firm up” properly
- promoting energy transfer
List three ways that potassium benefits plans.
Potassium benefits plants by improving drought tolerance, enhancing root growth, and activating enzymes involved in growth processes.
What term means “nonporous”?
impermeable
Define saturated.
completely filled with water
Give the term that describes any water located below the water table.
groundwater
What two factors determine the depth of the water table?
size and number of pores in soil; amount of recent rainfall
Define aquifer
layer of porous rock or a gravel-soil mixture that holds groundwater
What is the term for the upward movement of water through a tiny space in response to surface tension?
capillarity (or capillary action)
