More for teachers who do not have much science background than for students. Discusses the ideas of cycles and systems and goes into some detail about some representative sample cycles. This could be followed by the water cycle slide show: http://www.slideshare.net/MMoiraWhitehouse/teach-water-cycle-copy

1. • What do these words have to do
with science?
Cycles and Systems
•Cycles and Systems explore the constant
processes that surround us. All of the
Earth’s processes connect and work
together. From the movement of rocks to
the changing forms of water, we find that
less than 100 elements and the Sun's
energy are the keys to all living things.
Everything!
By Moira Whitehouse PhD.
Must be downloaded or saved in order to see the animations)

2. •In every discipline of science:
biology, geology, astronomy, meteorolog
y, physics and chemistry, we find that
whatever functions are being performed
they are frequently performed as part of
some cycle in some system. When one
part of a cycle fails or is removed, the
cycle and the system fails.

3. •And here is a list of a few systems:
Moon and Earth, Solar
system, galaxies, ecosystems, food web, all body
systems, (skeletal, digestive, immune, etc)
•Here is a list of just a few cycles:
electrical circuit, bicycle, gas engine, rock
cycle, water cycle, carbon cycle, nitrogen
cycle, phosphorous cycle, cycle of sunspots, moon
cycle, season cycle, Celoin cycle, Kreps cycle, food
cycle, cycle of constructive and destructive forces.

4. First, let’s look at cycles. What is a cycle?
• In general: Any complete round or series of
occurrences that repeats or is repeated.
• In science: An interval of time during which
a characteristic, often regularly repeated
event or sequence of events occurs:Sunspots increase and
decrease in intensity in
an 11-year cycle
• In science: A single complete execution of a
periodically repeated phenomenon:
A year constitutes a
cycle of the seasons.
• In science: A periodically repeated
sequence of events:
The cycle of
birth, growth, and
death

5. Next, we’ll look at systems. What is a system?
• In general: A combination of components
that act together to perform a function not
possible with any of the individual parts .
the nervous system;
the skeletal system
• In biology: A group of physiologically or
anatomically complementary organs or parts:
• In astronomy : a number of heavenly
bodies associated and acting together
according to certain natural laws:
the solar system;

6. •As we go through these few cycles and
systems, remember that this hardly
touches the surface...
•but it does cover some of the
major ones that fifth grade students
should be familiar with.
•In this order, we will look at:
•Life cycle of a plant (this presentation)
•The water cycle (a separate slide show)
•The nitrogen and carbon cycles (a separate
slide show)

7. Life cycle of a Plant

8. •The world of plants is large and complex.
•We will study only a small part, the life cycles
of angiosperms (flowering plants).
•The plant kingdom, however, includes many
other types of plants whose life cycles
will be very different the ones we will study.

9. •Here is a quick overview of the plant Kingdom:
I. Bryophytes: Small with
leaflike, stemlike, and rootlike structures.
Reproduce by spores:
mosses, liverworts, hornworts.II. Vascular Plants: Larger with true leaves,
stems, and roots.
B. Seed Plants:
1. Gymnosperms: Usually have cones, no
flowers, seeds not enclosed in fruit:
pines, spruces, firs, hemlocks, cycads,
A. Seedless: Reproduce by spores.
Ferns, horsetails, club mosses.

10. B. Seed Plants:
1. Gymnosperms: Usually have cones, no
flowers, seeds not enclosed in fruit:
pines, spruces, firs, hemlocks, cycads,
ginkgo.2. Angiosperms: Have flowers, seeds
enclosed in fruit.

11. Our aim in this section is to deepen our
understanding of the life cycle of
flowering plants, the angiosperms.
Most of us have a pretty good understanding
of the basic stages of the
flowering plant’s life cycle,
but at the nitty-gritty level,
things can become
complex.

12. As you may remember the life cycle of a
flowering plant fits into the following stages:
•Germination of the seed
•Seedling
•Mature plant
•Development of the fruit
•Flowering
•Fertilization
•Seed dispersal

13. As the following four processes are crucial to
plant survival, we examine each one.
•transpiration
•fertilization
•respiration
•photosynthesis
--the process of
metabolizing (burning)
glucose to yield energy
for growth, reproduction
and other life processes.
—the process by
which the chlorophyll
in plants captures
light energy which is
then used to convert
carbon dioxide and
water into a simple
sugar called glucose.
--the loss of water
vapor through the
stomata of leaves.--The joining of a male
and female cell.

14. photosynthesis
—the process by which the chlorophyll in
plants captures light energy which is then
used to convert carbon dioxide and water
into a simple sugar called glucose.
Let’s talk about
each of these.

15. During photosynthesis, the leaves of a plant
take in carbon dioxide from the air and
receive water from the soil. Using light
energy, the plant changes these ingredients
into a simple sugar called glucose.
--cross section of a leaf, where all this magic work takes place.
http://openlearn.open.ac.uk/
Creative commons attribution image

16. The chemical equation for the chemical change
involved photosynthesis is:
6CO2 + 6H20 = C6H12O6 + 6O2
carbon dioxide water glucose oxygen
Light energy provides the energy for this chemical
reaction.
Light energy

17. Plant cells have cell structures called chloroplasts
which contain chlorophyll, a green substance that
absorbs light energy. Chlorophyll is what gives
plant leaves their green color.
http://www.micrographia.com/
Images free for nonprofit use

18. Only plants can produce food though
photosynthesis. Animals cannot make
their own food. However, both plant
and animals cells respire— “burn”
glucose in order to secure energy to
carry out their life processes. In plants
that process is called “respiration”.

19. Respiration
--the process of metabolizing (burning)
glucose to yield energy for
growth, reproduction and other life
processes.

20. Remember, photosynthesis produces
glucose and now we will see how that
glucose is used by the plant (through
respiration) to get immediate energy for
growth, reproduction and to absorb
nutrients, etc.

21. Notice that the equation for respiration
is the opposite of photosynthesis:
C6H12O6 + 6O2 = 6CO2 + 6H20 + energy
In respiration, to grow and carry out its
life processes, a plant “burns” glucose.
During this process, the glucose produced
in photosynthesis combines with oxygen.
This chemical change results in the
release of carbon dioxide, water vapor
and energy.

22. 1. For storing food in seeds and roots. Before
winter, some plants stores starch in their
roots so they can survive the winter and
start growing again quickly in the spring.
Fats and oils are stored in seeds to use for
germination.
A plant changes some of the glucose
it manufactures into substances
such as starch, fats, and oils.
It uses these substances for two things.

23. 2. To build plant tissues such as
leaves, wood, flowers, fruit and roots.

24. http://ecosys.cfl.scf.rncan.gc.ca/
Images for use by public noncommerical use by Natural Resources Canada
Here we can see the two processes—
photosynthesis and respiration occurring
in a leaf.

25. The undersurface of leaves have holes
called stomata. This is where carbon
dioxide and oxygen from the air enter the
plant. It is also through these same holes
that carbon dioxide, oxygen and water
vapor are released.
http://www.micrographia.com/
Free images for nonprofit use
Image from Enchanted Learning

26. Water vapor
Water vapor
Carbon
dioxide
Carbon
dioxide and
oxygen
Oxygen
Water
Oxygen
Plants take up
the oxygen
they need
through their
their leaves
and through
their roots

27. Plants, animals and most microorganisms
need oxygen for respiration.
This is why for plants and microorganisms too
much water is deadly.
And we just saw that some of that oxygen
comes from the soil.
Overly wet or saturated soils are detrimental to
both root growth and function, and to the
decomposition processes carried out by
microorganisms in the soil.
Water fills the spaces in the soil forcing the
oxygen out.

28. Comparison of Photosynthesis & Respiration
Photosynthesis Respiration
Produces sugars from energy Burns sugars for energy
Energy is stored Energy is released
Occurs only in cells with Occurs in most cells
chloroplasts
Oxygen is produced Oxygen is used
Water is used Water is produced
Carbon dioxide is used Carbon dioxide produced
Requires light Occurs in both dark and
light

29. transpiration
--the loss of water vapor through
the stomata of leaves

30. Transpiration is the process by which moisture
is carried through plants from roots to small
pores on the underside of leaves, where it
changes to vapor and is released to the
atmosphere.
http://ga.water.usgs.gov/

31. Transpiration serves three purposes:
1. Movement of minerals up from the root (in the
xylem) and sugars (products of photosynthesis)
throughout the plant (in the phloem). Water serves
as both the solvent and the avenue of transport.
2. Cooling of the plant.
3. Turgor pressure. Water maintains pressure
in cells much like air inflates a balloon,
giving the non-woody plant parts form.
Turgidity is important so the plant can
remain stiff and upright and get to the light.
It also is the force that pushes roots through soil.

32. Carbon dioxide is absorbed through the
stomata (holes in the leaves) and water
vapor and oxygen are given off.
Image from NASA

33. Fertilization
The joining of a male and female cell.

34. To understanding fertilization in a flowering
plant will need to look at the parts of a
flower..

35. The pistil is made up of three parts: stigma, style
and ovary. The stigma is the sticky knob at the top
of the pistil. The style is the stem that holds up the
stigma and is attached to the ovary which contains
the female egg cells called ovules.
The female
part of the
flower is the
pistil which is
usually in the
center of the
flower.

36. A stamen is made up two parts:
The male
parts of the
flower are
called stamen.
They usually
surround the
pistil.
1. the anther at the top of the stamen which
contains pollen (the male reproductive cells) and
2. the filament which supports the anther.

37. Petals are also important parts of the
flower, because they help attract
pollinators such as bees, butterflies and
bats.
There are tiny green leaf-like parts called
sepals at the base of the flower. They help
to protect the developing bud.

38. During the process of
fertilization, pollen lands
on the stigma and a tube
grows down the style and
enters the ovary.
The male reproductive
cells travel down the tube
and join with the
ovules, fertilizing them.
Each fertilized ovule
develops into a seed and
the ovary becomes the
fruit.

39. The fruit is the ripened ovary of a plant
containing the seeds. After fertilization, the
ovary swells and becomes the fruit. Fruits may
be fleshy fruits, seed pods, or shells. Many
things we all call vegetables are really fruits
such as tomatoes, cucumbers and beans.
Wikipedia commons

40. In order for fertilization to take place, the
flower must be pollinated. Something
has to carry the pollen from the stamen
to the pistil usually of another flower.
Birds, bats and insects such as bees are
common pollinators.
http://www.flickr.comktjypryn http://www.flickr.comsharon, MA

41. Another way plants are pollinated is by
the wind. Grasses such as
wheat, oats, barley and corn are
pollinated by the wind.

42. Flowers such as those of
an oak tree, wheat, and
corn are pollinated by
wind.
Male tassels, female silks of a corn Stamens of a wheat flower
Flower of an oak tree

43. Bean seed
Part of every seed is a tiny plant (embryo)
with leaves, stems and root parts waiting
for the right condition to germinate. The
seed also contains a short-term supply of
stored food called the endosperm. It is
used by the embryo for growth until the
seedling can make its own food.

44. Part of every seed is a tiny plant (embryo)
with leaves, stems and root parts waiting
for the right condition to germinate.
The right conditions, of course will involve
there being some water there as well.
Which brings us to our next subject, water
and the
Water Cycle