7th GRADE STUDY GUIDE FOR CHAPTER 1: “CLASSIFYING & EXPLORING LIFE”
Big Idea: All living things have certain characteristics in common and can be classified using several methods. The
invention of the microscope has enabled us to explore life further, which has led to changes in classification.
Essential Questions:
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What characteristics do all living things share?
What methods are used to classify things into groups?
Why does every species have a scientific name?
How did microscopes change our ideas about living things?
What are the types of microscopes, and how do they compare?
Vocabulary to Know:
1) organism: things that have all the characteristics of life
2) cell: the smallest unit of life
3) unicellular organism: living things made of only one cell
4) multicellular organism: living things that are made of two or more cells
5) development: changes that occur in an organism during its lifetime
6) reproduce the process by which one organism makes one or more new organisms
7) fission: reproduction by dividing or splitting into two parts
8) stimuli: internal or external changes to the environment
9) internal stimuli: changes inside the organism (e.g.- hunger, thirst)
10) external stimuli: changes in the organism’s environment that affect the organism (e.g.- changes in light, temperature,…)
11) homeostasis: maintaining steady internal conditions when outside conditions change
12) kingdom: a classification category that ranks above phylum and below domain
13) systematics: current classiciation method that uses all evidence that is known about an organism to classify them (cell
type, habitat, how they obtain food/energy, structure, function of features, common ancestry, & DNA/molecular analysis)
14) domain: the hightest taxonomic rank of organisms in which there are three groupings: Archaea, Bacteria, and Eukarya
15) binomial nomenclature: a system for naming organisms developed by Carolus Linnaeus that gives each organism a twoword scientific name (e.g.- Ursus Arctos for brown bear)
16) species: a group of organisms that have similar traits and are able to produce fertile offspring
17) genus: a group of similar species (plural genera)
18) dichotomous key: a series of descriptions arranged in pairs that leads to the identification of an unknown organism
19) cladogram: a branched diagram based on phylogeny that shows the relationships among organisms, including common
ancestors
20) phylogeny: study of evolutionary relationships
21) light microscope: a microscope that uses light and lenses to enlarge an image of an object
22) compound light microscope: a microscope that magnifies an image first by an objective lens and then by an ocular lens
(total magnification is equal to the magnification of the ocular lens and objective lens multiplied together)
23) stereo light microscope: a microscope that gives a 3-D view of object; objective and ocular for each eye… used to look at
thick structures light can’t pass through
24) Electron microscope: for objects way too small to be seen with a light microscope; uses magnetic field to bend beams of
electrons and can magnify 100,000 times or more
25) Transmission Electron Microscope (TEM): electrons pass through an object that has been sliced thin and placed in a
vacuum… to observe nonliving objects only
26) Scanning Electron Microscope (SEM): electrons bounce off the object; used to see surfaces of whole objects; to observe
living things
Know:
-the characteristics that all living things share (organization, growth & development, reproduction,
response to stimuli, homeostasis, use of energy) “Our Good Dog Really, Really Hates Elephants”
-how to interpret a food web
-the six-kingdoms of living things
-the three domains of life (bacteria, archaea, and eukarya)
-“Kings Play Cards Over Family Games Sometimes” …
Kingdom, Phylum (Division in Plant Kingdom), Class, Order, Family, Genus, Species
-that Kingdoms are divided into Phyla or Divisions, Phyla are divided into Classes, etc.
-that a genus can have one or more species
-how to construct and use a ‘dichotomous key’
-why every species has a scientific name
-the types of microscopes and how they compare
-The Scientists
*Aristotle- Greek philosopher who first classified organisms as plants or animals
*Linnaeus- Swedish physician and botanist who classified organisms into 2 main kingdoms and
developed the two-word naming system… binomial nomenclature
*Whittaker- American Biologist who proposed the 5-kingdom system (Monera, Protista, Plantae, Fungi,
and Animalia)
*Janssen- created first compound microscope
*Leeuwenhoek- made a simple microscope with a tiny glass bead for a lens
*Hooke- studied cork ‘cells’; discovered cells