Transcript S7L1. Students will investigate the diversity of living organisms and

7th Grade Science Standards Review
7th Grade Science Standards Review
S7L1. Students will investigate the diversity of living
organisms and how they can be compared
scientifically.
a. Demonstrate the process for the development
of a dichotomous key.
b. Classify organisms based on physical
characteristics using a dichotomous key of the
six kingdom system (archaebacteria, eubacteria,
protists, fungi, plants, and animals).
Dichotomous Keys
Dichotomous – means divided into two parts
Therefore, you will always have two choices
until you get to the answer.
Major Animal Groups
Does it have a backbone or no backbone?
It has a vertebral column or backbone and thus fits
category (1a), Phylum Chordata, which sends you
to couplet 2.
1a
1b
Vertebral column present
Vertebral column absent
Phylum Chordata 2
8
It has no hair, which sends you to 3. You notice there
are no feathers, you proceed to 4.
2a
2b
Hair present
Hair absent
Class Mammalia
3
3a
3b
Feathers present
Feathers absent
Class Aves
4
It has fins, so you move to 5. There are jaws, go
to 6.
Jaws
Fins
4a
4b
Fins present
Fins absent
5a
5b
Jaws present
Jaws absent
5
7
6
Class Agnatha
Its gills are covered by an operculum (bony plate
covering gills) which places the organism in Class
Osteichthyes, the true bony fish.
Operculum
6a Gills covered by an operculum
Class Osteichthyes
6b Gills not covered by an operculum Class Chondrichtyes
Levels of classification:
Domain—most general
Kingdom
Phylum
Class
Order
Family
Genus
Species—most specific
6 Kingdoms of Life
1.
2.
3.
4.
5.
6.
Archaebacteria
Eubacteria
Protists
Fungi
Plant
Animal
S7L2. Students will describe the structure and
function of cells, tissues, organs, and organ systems.
a. Explain that cells take in nutrients in order to
grow and divide and to make needed materials.
b. Relate cell structures (cell membrane, nucleus,
cytoplasm, chloroplasts, mitochondria) to basic
cell functions.
c. Explain that cells are organized into tissues,
tissues into organs, organs into systems, and
systems into organisms.
d. Explain that tissues, organs, and organ systems
serve the needs cells have for oxygen, food, and
waste removal.
e. Explain the purpose of the major organ systems
in the human body (i.e., digestion, respiration,
reproduction, circulation, excretion, movement,
control, and coordination, and for protection
from disease).
Cell Theory
1. All organisms are made of one or
more cells.
2. The cell is the basic unit of all
living things.
3. All cells come from existing cells.
Eukaryotic Cells
1. Organelles – tiny parts of a cell
2. Organelles
A. Cell wall – rigid outer covering of
plant cells, bacteria, fungi
B. Cell Membrane – inside the cell wall
of plants, outer covering of animal cells
(1) Controls what goes in/out of cell
C. Nucleus – controls the cell; dna
(1) Nuclear membrane – outer covering
D. Cytoplasm – jelly like substance,
supports organelles
E. Mitochondria – energy producer
F. Endoplasmic Reticulum (ER) - transport
G. Ribosomes – makes proteins
H. Golgi Bodies - packages
I. Chloroplasts – plants – food maker
J. Vacuoles – storage container for food,
water and waste
K. Lysosomes – cleanup crew - animals
3. Prokaryotes – no nucleus - bacteria
4. Eukaryotes – cells with a nucleus
Cell—basic unit of life
Tissue—Groups of cells working together
Organ—groups of tissues working together
Organ System—Groups of organs working together
Organism—all of the organ systems working together
Plant cells have to make their own food before
the mitochondria can break it down for energy
(ATP).
Plants make food in the chloroplast through a
process known as photosynthesis.
(Ingredients)
6CO2 + 6H2O + sunlight 
Carbon
Dioxide
Water
(Results)
C6H12O6 + 6O2
Glucose
(food)
Oxygen
Major Systems:
Digestive
Integumentary
Respiratory
Excretory/Urinary
Reproductive
Endocrine
Circulatory/Cardiovascular
Nervous
Muscular
Immune
Skeletal
Digestive System
• Breaks down food into molecules
• Molecules are absorbed into blood and
carried throughout the body
Respiratory System
How our bodies get and use oxygen and release
carbon dioxide and water
Two parts
Breathing
Cellular respiration (energy release from food)
Reproduction System
System responsible for human reproduction
(having babies)
Circulatory System
Transport oxygen and carbon dioxide
Distribute nutrients
Transport wastes
Distribute hormones
Regulate body temperature
Nervous System
Two main functions:
1. Gather and interpret information
2. Respond to that information as needed
Responsible for Coordination and control
Skeletal System
Composed of bones, cartilage, and the
connective tissue that holds bones together
Primary Function:
•Support and protect the body and allow
movement
Muscular System
1. Is made of muscles
2. Allows movement and flexibility
Immune System
1. Fights pathogens (fights disease)
2. Is a team of individual cells, tissues, and
organs that work together to keep you
healthy
S7L3. Students will recognize how biological traits
are passed on to successive generations.
a. Explain the role of genes and chromosomes in
the process of inheriting a specific trait.
b. Compare and contrast that organisms reproduce
asexually and sexually (bacteria, protists, fungi,
plants & animals).
c. Recognize that selective breeding can produce
plants or animals with desired traits.
A. Genes - pieces of chemical information found on
chromosomes that carry instructions for making
all the proteins that a cell needs.
B. Most genes are either dominant or recessive
C. Dominant trait is the trait you can see
TT (capital letters); Tt
D. Recessive trait is seen if dominant one isn’t
present tt (lower case)
Incomplete Dominance - neither gene is
dominant or recessive. (a “blending”)
(1) Example - White flower (WW)
crossed with red flower (RR).
(a) pink
Co-dominance – both genes show up;
they dominate together
Ex: black chicken (BB) crossed with
White chicken (WW).
(a) babies with both black and
white feathers
Phenotype vs. Genotype
A. Phenotype is what you see when you look at
an organism
B. Genotype is the actual gene combination an
organism has
Example
Phenotypes and Genotypes
Tall
TT
Tall
Tt
Short
tt
Homozygous vs. Heterozygous
A. Homo-means same
B. Homozygous—Alleles are the same—can
be either dominant or recessive
example TT or tt
C. Hetero-means different
D. Heterozygous—Alleles are different
example Tt
Punnett Square review
1.Write down what you know (parent genotypes,
which trait is dominant, etc.)
2.Draw box
3.Put one parent on top one on the side
4.Drop and slide
Problem 1. In seals, long whiskers (W)
are dominant and short whiskers (w)
are recessive. The parent genes are
WW and Ww. Find genotype,
phenotype and probability for offspring.
Problem 2. In seals, long whiskers (W)
are dominant and short whiskers (w)
are recessive. The parent genes are
Ww and Ww. Find genotype,
phenotype and probability for offspring
Problem 3. In purple people eaters,
horns are dominant and no horns are
recessive. Parent gene codes are Hh
and hh. Find genotype, phenotype and
probability.
Organisms reproduce one of two ways:
1.Asexually (one parent)
Offspring is genetically identical to parent
2.Sexually (two parents)
Offspring is genetically different to parent
Selective breeding can produce plants or animals
with desired traits.
Kingdom
Cell Type
(eukaryotic or
prokaryotic)
Archeabac
Prokaryotic
teria
Eubacteria Prokaryotic
Protists
Eukaryotic
Food
Number of
(autotrophic or Cells
heterotrophic) (unicellular or
multicellular)
Either
Either
Either
Unicellular
Where do they
live?
How do they
reproduce?
Hostile
environments
Asexual- binary
fission
Sexual-conjugation
Unicellular
Everywhere
Asexual- binary
fission
Sexual-conjugation
Either
Water and
Moist
surroundings
Either
multicellular;
Fungi
Eukaryotic
Heterotrophic
Except yeastunicellular
Land and water Either
Plants
Eukaryotic
Autotrophic
Multicellular
Land and water Sexually
Animals
Eukaryotic
Heterotrophic
Multicellular
Land and water Sexually
S7L4. Students will examine the dependence of
organisms on one another and their environments.
a. Demonstrate in a food web that matter is
transferred from one organism to another and
can recycle between organisms and their
environments.
b. Explain in a food web that sunlight is the source
of energy and that this energy moves from
organism to organism.
c. Recognize that changes in environmental
conditions can affect the survival of both
individuals and entire species.
d. Categorize relationships between organisms that
are competitive or mutually beneficial.
e. Describe the characteristics of Earth’s major
terrestrial biomes (i.e. tropical rain forest,
savannah, temperate, desert, taiga, tundra, and
mountain) and aquatic communities (i.e.
freshwater, estuaries, and marine).
Energy for a food chain comes from the sun!
A close relationship
between two organisms is
known as symbiosis.
There are three types of
symbiosis.
1. Mutualism—both organisms benefit
2. Commensalism—one organism benefits while
the other is unaffected
3. Parasitism—one organism benefits while the
other organism is harmed
Biome—group of ecosystems with similar
climates
• 6 land
• 2 water
1)
2)
3)
4)
5)
6)
7)
8)
Rain Forest (tropical or temperate)—rainy
Desert—very dry
Grassland (Savanna, Prairie)
Deciduous Forest—4 seasons
Taiga (Boreal or Coniferous forest)
Tundra—frozen soil (permafrost)
Freshwater—lakes, rivers, streams
Marine—brackish and salt water
S7L5. Students will examine the evolution of living
organisms through inherited characteristics that
promote survival of organisms and the survival of
successive generations of their offspring.
a. Explain that physical characteristics of
organisms have changed over successive
generations (e.g. Darwin’s finches and peppered
moths of Manchester).
b. Describe ways in which species on earth have
evolved due to natural selection.
c. Trace evidence that the fossil record found in
sedimentary rock provides evidence for the long
history of changing life forms.
Adaptation—characteristic that helps an organism
survive and reproduce
A. Physical (ex. Long neck, striped fur)
B. Behavioral
Evidence of Change over time
A. Fossils—trace or remains of an organism
that lived long ago
1. Most often found in sedimentary rock
B. Fossil Records—using fossils to make a
timeline of life on earth
Charles Darwin
A.First to explain how evolution happens
B.Known as the “Father of Evolution”
Evolution happens through
Natural Selection
1. Process where organisms better adapted to
their environments are more likely to survive
and reproduce
Some genes make an organism more likely to survive
to reproduce