Key Scientific Knowledge
(KSK)
Lesson
1: |
How do seeds germinate? ·
Seeds
are plants “in a period of dormancy” (Delaware State University (DESU), 2010)
where the said awaits the optimum conditions in order to germinate. ·
Seeds
need three things in order to begin germination: water, oxygen, optimum
temperatures and for some seeds; light. (Royal Tasmanian Botanical Gardens
(RTBG), 2009) ·
The
first step in seed germination is when the seed coat or the “Testa” (DESU, 2010, para 1)
breaks open to allow the “radicle” (DESU, 2010) through which is the first
root for the plant. ·
Roots
grow downwards “because they detect the pull of gravity” (Primary
Connections, 2012). ·
After
this has occurred, the “plumule” (RTBG, 2009) or
the first shoot pushes up towards the top of the soil. The plumule will later develop into the plant’s leaves and
stems (RTBG, 2009). ·
Inside
the seed is also the “cotyledon” (Primary Connections, 2012, p.23) which
provides the plant with food for germination (Primary Connections, 2012). In
some seeds, the cotyledon remains inside the seed providing food to continue
growing (such as in pea seeds (Bates,1990)), while
in others, the cotyledon is pulled out by the plumule
to become the first leaves of the seed to provide food via photosynthesis
(such as in sunflower seeds (Bates, 1990)). ·
From
here if the conditions remain optimum the plant begins to grow. |
Lesson 2: |
Parts
of a flower ·
Petal:
attracts pollinators (Colorado State University Extension (CSUE), 2009). ·
Pistal:
contains female organs (CSUE, 2009). ·
Stigma:
“receives pollen, typically flattened and sticky” (CSUE, 2009). ·
Stamen
– made up of anther & filament (Primary Connections, 2012). ·
Ovary
– contains ovules which is where seeds are made (Primary Connections, 2012). ·
Sepal
– “Protective leaf-like enclosures for the flower buds, usually green” (CSUE,
2009). ·
Flowers
are nature’s way of attracting pollinators to the plant in order to fertilise
the flower (Stidworthy, 1989). ·
Pollen
must reach the stigma which feeds the pollen to the ovary where the egg cells
(ovules) of the plant become fertilised (Morgan, 1993). ·
The
fertilised ovules then develop into seeds (Morgan, 1993). How do
flowers produce seeds? ·
Flowers
attract pollinators who deposit pollen from the stamen of one flower to
another flower (Primary Connections, 2012). ·
In order for a flower to become fertilized
and produce seeds, the pollen causes the pollen tube in the stigma to swell
and lengthen towards the ovary where it will eventually allow the pollen to
fertilise the ovules (Bates, 1990). ·
The
ovules enlarge and begin to develop into a seed. ·
The
flower of the plant is replaced by a growing fruit which contains the seeds
ready for dispersal (Bates, 1990). ·
There
are several ways seeds can be dispersed: by wind, through a carrier such as birds,
by fire (Australian natives) or some plants have developed a method of
shooting their seeds out of their pods and into the environment (ABC Splash,
2013). ·
In
some circumstances, fruit can decompose which enables the seeds inside the
fruit to begin germination. (Rubenstein, Clearly & Siry,
2009) ·
As
plants decompose they begin to change and break down. In the environment this
contributes to the nutrient content in soil (Boundless, 2013) What is photosynthesis and how
does it work? ·
Photosynthesis
is the process by which plants manufacture sugars which provide the plant
with food (Robertson, 2007). ·
Photosynthesis
can be thought of as a recipe in that it requires all the right ingredients
in order to work. ·
Photosynthesis
begins when light is taken in by chloroplasts which have flat sacs inside
called thylakoids (Robinson, 2007). ·
Inside
thylakoids are “two high energy molecules, poised to provide the energy
needed to create sugar out of carbon dioxide” (Robinson, 2007, p. 61). When
light reaches the thylakoids it converts the light energy into chemical
energy (Stein Carter, 1999) which is then absorbed by these molecules. These
now energised molecules are used by the plant to convert carbon dioxide and
water in to glucose (Robinson, 2007). The glucose is then used by the plant
as food. ·
Carbon
dioxide is taken into the plants by stomata, tiny openings on the underside
of the leaf that allow carbon dioxide into the leaf and oxygen out. ·
The
chemical equation for photosynthesis is: Sun’s energy CO2 + H20 = > C6H12O6 + O2 |
Lesson 3: Insect Life Cycles – Silkworms |
·
Insects
undergo ‘Metamorphosis’ which involves change in their bodies through cell
growth and transformation. Insects and amphibians undergo metamorphosis. A
metamorphosis can be either complete (4 stages) or incomplete (3 stages).
Please see website to learn more about these: http://australianmuseum.net.au/Metamorphosis-a-remarkable-change ·
Female
silkworms will lay up to 300-500 eggs at one time then dies (Kellyville Pets,
2009). ·
Eggs
hatch in spring ·
4
stages in life cycle - Egg, larva, pupa and adult (Complete metamorphosis) ·
Download
silkworm fact sheet to learn more about stages - http://www.kellyvillepets.com.au/fact-sheets
·
It
takes up to 4 weeks for a baby silkworm to fully grow into their adult size –
6-8cm in size. ·
Silkworms
do not have lungs – they breathe through tiny holes on the sides of their
bodies (Burke’s Backyard, 2013). ·
27
days after hatching a silkworm will begin to spinning its cacoon. ·
A
silkworms cacoon can be either yellow or white depending on their diet ·
Silkworms
eat mulberry leaves – they eat a lot during their larvae stage. ·
YouTube
offer live streaming – create an account and children can access video
anytime on YouTube via their computers at home. ·
Timershot is a program that takes numerous photos of something as
it records. Images can be converted into a video. |
Lesson 4: Exploring the outdoors |
·
To
have a broad knowledge of insects and to be familiar with common types –
ladybugs, grasshoppers, beetles, butterflies, cicada etc. Please use website
to learn more about specific insects common in Australia: http://www.ozanimals.com/australian-insect-index.html ·
How
to use PowerPoint- Tutorial on how to use it can be found here: http://www.youtube.com/watch?v=JYhUr4NoDbI ·
Incomplete
metamorphosis – Egg, nymph, adult. Complete metamorphosis – Egg, larva, pupa,
adult (Australian Museum, 1968). |
Lesson 5: Group Stations |
·
Insects
such as grasshoppers, cockroaches, praying mantis, dragonfly, stink bug and
termites all undergo an incomplete metamorphosis (More information: http://museumvictoria.com.au/bugs/life/cycles.aspx) ·
Insects
such as lady beetles, butterflies, silkworms, a fly, beetles, ants and fleas
all undergo a complete metamorphosis (More information: http://askabiologist.asu.edu/complete-metamorphosis)
·
Timershot tutorial: http://techtutorials.edublogs.org/2011/11/09/timelapse/ Microsoft Office - http://www.youtube.com/watch?v=x9L-i0WPqNc |
Lesson 6: Turtle Life Cycles |
·
Turtles live between
40 & 200 years (Sea
Turtle Foundation Ltd, 2009). ·
Diversity of turtles
i.e. 300 species around the world and some turtles are small at 140 grams
& some weigh 900 kilograms (Wikipedia,
2002). ·
Different species
live in different habitats. See http://animal.discovery.com/reptiles/turtle-info.htm and turtles can live both on land & in water as they
breathe in both environments. ·
The female sea
turtle comes onto land to lay her eggs (using hind legs to dig the hole in
the sand). The clutch of 50-170 ping-pong ball-like eggs incubates for 6-13
weeks. They lay between 3-7 nests per season(Musick
& Lawrence, 2003). ·
A variety of factors
can affect the hatching success of sea turtles. Such as temperature, natural
predators, environmental issues such as plastic bags, fishing nets, oil
spills & sand mining (Musick
& Lawrence, 2003) and only one in a thousand hatchlings survive the 30-50
years it takes a sea turtle to reach breeding age (Canin
& Henkel, 2006). ·
More life cycle
information can be obtained from many websites including www.seeturtles.org ·
Visit http://www.turtlesrus.com.au/caresheet.html for purchase of eggs or baby turtles and also information
on keeping turtles as pets and the requirements. ·
Reptile license
application form can be obtained from the above website or embedded HERE. The cost is $50.00 for the license. ·
More information can
be obtained from http://turtlesaustralia.org.au/Default.aspx?pageId=1364543 |
Lesson 7: Food Cycles |
· An
ecosystem is a community where living things interact in conjunction with
other living and non living things through nutrient cycles and energy flows (Mader, 2000) · The
human population modifies existing ecosystems for its own purposes (Mader, 2000) · Life
Cycles are also known as Reproductive Cycles (Skamp, 2012). · Life
cycles include birth, environmental requirements for life like food and sun,
threats to life like predation, reproduction and finally death. · Food
cycles are often seasonal (Skamp, 2012) · A
food chain is a sequence of who eats who to obtain food for nutrition and
energy (Enchanted Learning, n.d) · A
food pyramid is the “natural consequence of the way energy flows through an
ecosystem” (Skamp, 2012, p. 269) · Producers are the start of a food
chain. Producers are plants and vegetables that require the sun to survive. (Geography4kids, 2013) · There
are two levels in the second phase of the food chain: a) Herbivores who eat
plants and b) carnivores who eat meat. Omnivores who eat both and almost
anything – like humans (Geography4kids, 2013) · Decomposers
are the final link in the food chain. Decomposers are mostly fungi that break
down dead animals and other organic wastes (Geography4kids, 2013). · Fires
are considered necessary for renewal of habitats and ecosystems. Fires can
help environments re-establish themselves through germinations and regrowth,
necessary for the other living things that depend on them (Mader, 2000).
Aboriginal cultures used fires to assist with regeneration to maintain their
food cycle, drive snakes away and avoid wild fires (Jenolan Caves, n.d). |
Lesson 8: Excursion to Taronga
Zoo |
·
Insects
perform a vast number of important functions in our ecosystem (Warren, 2002). ·
If
insects were to disappear, humanity and most other life forms, would also
become extinct because of the domino effect that would occur in the food
chain (Wilson, 2010). ·
All
insects are invertebrates. ·
All
living things are placed into groups depending on common characteristics. The
animal kingdom is divided into vertebrates and invertebrates (CSIRO, 2013). ·
Invertebrates
have no backbone, unlike animals such as reptiles, amphibians, fish, birds
and mammals who all have a backbone. ·
More
information can be obtained from: http://www.ento.csiro.au/education/index.html and http://www.riverdeep.net/current/2002/03/030402t_insects.jhtml |
Lesson 9: Concluding lesson |
No new KSK
introduced as this is an opportunity for students to consolidate the
knowledge they have gained from this unit. |