Pre-Lab Quiz 1

Steps to the scientific method

make observations, ask questions, check accumulated data, formulate hypotheses, run multiple controlled experiments, make conclusions, and accept or reject hypotheses, report findings

Scientific question

Questions end in “?” and are testable predictions.

Hypothesis

a prediction, which may refute (not falsify), or support (not prove) a finding or question

Independent variable

variable that is tested/manipulated. Always on the X axis of a graph and should only have one independent variable tested at a time. (Type of plant)

Dependent variable

variable that is being measured. Always on Y axis except if the dependent variable is. (how high it grows in meters)

Treatments

each individual version of the independent variable (Bean stalk, flower, tomato plant)

Standardized variables

factors that remain the same across all groups in an expirement that could affect the dependent variable (make sure all plants grow in the same temperature and same amount of sunlight)

Control

the version of the independent variable that you compare experimental treatments to/baseline

Sample size

number of individual/populations in an experiment

Replication

repeating an experiment at a different time or with a different scientist

The origin of biological classification

Carolus Linnaeus is Swedish medical doctor, botanist, and devout Christian. Linnaeus published systema naturae which classified all known organisms and is still used today. Linus believed that God had a natural classification which needed to be discovered. Classifications and relatedness are now solely based on evolutionary relationship

Dichotomous Tree

each branches split between two groups, and each branch ends with a single unique organism.

Nondichtomous tree

each branch may include more than one organism

Phenogram

traits organized to what is most useful to the phenogram maker. Most commonly use dichtomous branching as it gives specific classification for each item

Phylogenies

tree diagram specifically for homologous traits and show path of evolution

Homologies

traits that appear in different organisms because they were inherited by a common ancestor

Homoplasies

similar treats between organisms that evolved independently/not common ancestor. Can be from convergent or reverse evolution.