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7th Grade Life Science SLEs
(Student Learning Expectations)

LS.2.7.1 Illustrate the hierarchical
relationships of cells, tissues, organs, and
organ systems



The spinal cord and nerves carry information
to the brain, and the brain sends signals to the
body through the spinal cord and nerves.
The trachea carries air containing oxygen to
the lungs.
The stomach breaks down food particles into
small enough pieces that they may be
digested more in the small intestine and sent
out to the cells for energy use.
The kidneys clean the blood, the bladder
holds urine until the body is ready to excrete
it and then the urine leaves through the
urethra.
LS.2.7.3 Identify organ systems in vertebrates
and plants
See the page 2A chart on the human body for vertebrates.
Systems Comparisons
The levels of organization in the
correct order are:
cells --> tissues --> organs --> organ
systems --> organisms
1. similar cells form tissues
2. similar tissues form organs
3. various organs working together form
organ systems
4. organ systems working together form
the organism.
LS.2.7.2 Analyze how two or more organs
work together to perform a function (e.g.,
mouth and stomach to digest food)
 The ligaments hold bones together at joints
 In the muscular system one muscle (biceps)
pulls the lower arm up, and another muscle
(triceps) pulls the arm down.
 The heart pumps blood out to the blood
vessels (arteries, veins, and capillaries) so
they can carry needed food and oxygen to all
the cells of the body.
Needs and
Functions
Human
Organ
System
Plant
Organ
System
Support the
body
Skeletal
system
Stem
system
Transport
nutrients
Circulatory
system
Stem
system
(vascular)
Reproduce
Reproductive
System
Flower
system
(sexual)
Remove
wastes
Excretory
system
Root and
Leaf
systems
Use or make
energy
All systems
All
systems
Provide a
barrier to the
outside
environment
Skin system
Epidermal
system
Takes in water Digestive
and nutrients
system
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Root and
Leaf
systems
Plant organ systems:
 Root
 Stem
 Leaves
 Reproductive (flower, cone)
LS.3.7.1 Explain that the fertilized egg cell
carries genetic information from each parent
and multiplies to form a complete organism
 The human female sex cell (egg) contains
23 chromosomes
 The human male sex cell (sperm)
contains 23 chromosomes
 The fertilized egg, therefore contains the
23 from each parent making a total of 46
chromosomes with genetic material from
both parents.
 The fertilized egg implants in the
female’s uterus and begins to divide and
multiply to form the complete organism.
LS.2.7.4 Analyze the structure and function of
tissues, organs, and organ systems of a
vertebrate and an angiosperm using various
models or methods of dissection
See the page 2A chart on the human body.
LS.2.7.5 Compare and contrast vertebrate
systems and plant organ systems
See the chart on page 1, LS.2.7.3
LS.2.7.6 Identify human body systems:
nervous, digestive, circulatory, respiratory,
excretory, integumentary, skeletal/muscular,
endocrine, reproductive
LS.3.7.2
Distinguish between sperm cells and egg cells
egg
Female sex cell
Among the largest
cells in the human
body
Does not move on its
own
See the page 2A chart on the human body.
LS.2.7.7 Relate the structure of vertebrate
and plant body systems to their functions
 The skeletal system is structured to
support and surround and protect the
other organ systems. (ex. Ribs protect
heart and lungs, etc.)
 The muscular system is structured so that
the muscles can pull on bones to help us
move.
 The flower of the angiosperm is
structured so that the stigma is high so
that pollinators like bees will touch it and
leave pollen
Female has all eggs
she will ever have at
birth
sperm
Male sex cell
Among the smallest
cells in the human
body
Mobile – moves itself
about using a tail-like
structure (flagellum); it
travels to the egg
Male has ongoing
production of sperm
beginning at puberty
LS.3.7.3 Compare and contrast the structure
and function of the sperm cell and the egg cell
in vertebrates and plants and their role in
sexual reproduction
 In angiosperms (flowering plants, seeds
in fruits), the fertilized egg becomes a
seed which contains a seed coat and food
for the developing embryo.
 In both vertebrates and seed plants
o the sperm is the male
reproductive cell and the egg is
the female reproductive cell
o the sperm is much smaller than
the egg
o the sperm must travel to the egg
o the sperm and egg unite during
fertilization
LS.2.7.8 Investigate functions of human body
systems
See the page 2A chart on the human body.
LS.2.7.9 Describe interactions between major
organ systems
 The skeletal and muscular systems work
together to move your body
 The respiratory, digestive, and circulatory
systems work together work together to
provide energy for your body activities,
including movement
 The reproductive, digestive, respiratory,
and circulatory system work together to
provide nourishment for the embryo/fetus
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(such as blood cells, kidney cells, and nerve
cells). The end of the eighth week marks the
end of the "embryonic period" and the beginning
of the "fetal period (It is now a fetus)."
The period of time between conception
and birth during which the fetus grows and
develops inside the mother's womb is called
gestation.
LS.3.7.5 Dissect a poultry egg to analyze its
structure (e.g., paper, plastic, or clay models,
virtual dissection, or specimen dissection)
LS.3.7.4 Investigate and analyze the
development of embryos
Fetal Development Chart:
Cross Section of a Newly Laid Egg
1. shell - Protects the embryo (chick)/Gives
air for the chick with it's pores
2. shell lining - Protects the embryo
(chick)/waterproof so water can't get in
OR out.
3. egg white - Protects the embryo
(chick)/Provides embryo (chick) with
water.
4. chalaza - Protects the embryo (chick)
from vibrations (also acts like a seat belt).
5. egg yolk - Provides food for the embryo
(chick)
6. air sac - a sac of air at the bottom of the
shell.
7. embryo - Where the chick grows out of
on the egg yolk.
Zygote: A single sperm penetrates the
mother's egg cell, and the resulting cell is
called a zygote. The zygote is a single cell. The
zygote contains all of the genetic information
(DNA) necessary to become a child. Half of the
genetic information comes from the mother' s
egg (23 chromosomes) and half from the father' s
sperm (23 chromosomes) for a total of 46
chromosomes in the zygote. The zygote spends
the next few days traveling down the Fallopian
tube and divides to form a ball of cells.
Cells divide to form the EMBRYO: The
cells of the embryo now multiply and begin to
take on specific functions. It leads to the
various cell types that make up a human being
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LS.3.7.6 Dissect a flower to analyze the
reproductive system of angiosperms (e.g.,
paper, plastic, or clay models; virtual
dissection; or specimen dissection)
LS.3.7.7 Differentiate between sexual and
asexual reproduction in vertebrates and
plants
Asexual
Reproduction
Offspring are
exactly like
parent – clones
Only 1 parent
No sex cells
Both Asexual
and Sexual
Reproduction
Produce
offspring
Requires at
least one
parent
Happen only
in living
things
Insures
survival of
the species
Sexual
Reproduction
Offspring have
traits from both
parents
2 parents
Female sex cell –
egg
Male sex cell –
sperm
Happens in
animals and seed
plants
LS.3.7.8 Identify the number and source of
chromosomes in human body cells
 23 chromosomes from the mother (egg)
Stamen: Male reproductive parts of the flower:
 anther: produces pollen
 filament: holds the anther in place
 pollen: contains the males sperm, made by
the anther


Pistil (carpel): Female reproductive parts:
 stigma: receives the pollen during
fertilization; it is sticky to grab and hold the
pollen in place
 style: tube between the stigma and ovary
through which the pollen tube must grow to
deliver the sperm to the egg (ovule)
 ovary: organ where the ovules (eggs) are
produced; will become the fruit of the plant
 ovule (egg): the female reproductive cell;
will become the seed
23 chromosomes from the father
(sperm)
46 chromosomes in all the other cells of
the human body because they come from
cell division of the fertilized egg. The
fertilized egg has 46 chromosomes, 23
from the mother’s egg and 23 from the
father’s sperm
LS.3.7.9 Identify the number and source of
chromosomes in human sex cells.
Human Sperm Cell
23 chromosomes
from the father
Other parts of the Flower:
 petal: the colorful part of the flower that
attracts pollinators
 sepal: leaf-like parts that protect the bud
 receptacle: wide part under the flower
that supports the flower
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Human Egg Cell
23 chromosomes
from the mother
Essentially, homeostasis is the whole of
your body's efforts to maintain optimal
health and proper balance.
Homeostasis examples:
 When you are too hot, your nervous
system and integumentary system (skin,
hair, nails) work together to help you
sweat (perspire) to cool down.
 When you need extra energy from a
stressful situation such as a race, your
endocrine system releases adrenaline
(hormone) into your bloodstream
(circulatory system). The adrenaline gives
you the needed burst of energy.
 As you are running, your muscles need
more energy. You breathe faster to get
more oxygen and your heart beats faster to
carry the oxygen to your cells faster and
carbon dioxide waste away faster.
See previous LS.3.7.8
LS.3.7.10 Explain the role of cell division
 To pass on identical genetic material to 2
daughter cells
o Repeat the process over and over
without error
 Growth and Development of the
organism before and after birth
All the body systems work together to keep your
body in balance and stable (homeostasis.)
LS.4.7.1
Explain the role of reproduction in the
continuation of a species
Reproduction is necessary to ensure
the continuation of each type of living thing.
Without reproduction, once all the members
of the species die, there will be no
offspring to continue the species. This is
known as extinction of the species.
LS.3.7.12
Summarize the interactions between organ
systems in the maintenance of homeostasis
Homeostasis is the process by which an
organism’s internal environment is kept
stable in spite of changes in the external
environment.
Homeostasis is how your body maintains
 steady temperature pattern
 stable flow of blood through the
body, which provides optimal
nourishment and oxygen to the cells
while effectively whisking away
toxins
 healthy intake of oxygen and
disposal of carbon dioxide
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