Transcript Phylum Chordata

1
Page 87
ABBOTTSCOLLEGE
ROLES OF THE INVERTEBRATES
2
Pollination
Decomposition
Soil aeration
Page 87
POLLINATION
PAGE 87
3

Is the transfer of ripe pollen containing the male
gametes from the anthers to the stigma to allow
for fertilization
IMPORTANCE OF POLLINATION
4
Without pollinators:
Natural ecosystems
would collapse
Agricultural production
would be badly
affected and humans
would be short of food
DEFINITIONS
5
Pollinator = animal
that moves the
pollen
Polleniser = the
plant from which
the pollinators get
their pollen
BEST INSECT POLLINATORS
6
Butterflies
Moths
Ants
Flies
Beetles
Bees
BEES
7
Most of their life is
spent collecting
pollen
Honey bee is the
most commonly
used agricultural
pollinator
CROPS POLLINATED BY INSECTS
8
Fruit crops
Vegetables
Oilseed
crops
Nuts
Coffee and
cocoa
PROBLEMS
9




Bee populations are declining
Fields/orchards and monocultures have led to
crops needing managed pollination
Pollination management involves agricultural
practices that ensure the pollination of a crop so
that the yield and quality of the crop is improved
Often involves commercial beekeepers becoming
pollination contractors and transporting the bees
to areas where they are needed
MONOCULTURE
10
DEFINITION
Monoculture is
the agricultural practice of producing or
growing a single crop or plant species
over a wide area and for a large
number of consecutive years.
It is widely used in modern industrial
agriculture and its implementation has
allowed for large harvests from minimal
labour.
DECOMPOSITION
PAGE 88
11
Is a biological process that
includes the physical and
chemical breakdown of complex
organic molecules of dead
material into simpler organic
and inorganic molecules
It is brought about by
invertebrates and microorganisms
INVERTEBRATES
12




Beetles, slugs and worms feed on
organic material, breaking it down
They break down plant litter (dead
roots, leaves and grasses) =
detritus
A complex stable organic material
called humus is formed
Which improves the texture of soil
and adds nutrients to it
MICRO-ORGANISMS
13
Complete the breakdown process of organic matter
Nitrogen, phosphorus and sulphur are released into the soil
14
SOIL AERATION
PAGE 89
15
Earthworms feed on
detritus which they
drag down into their
burrows
Burrowing improves
soil drainage by
creating passageways
for air and water
Worms excrete casts
Worms work as pistons
forcing air through the
tunnels and aerate the
soil
Tunnels also allow
roots to penetrate into
the soil
DEFINITION
Vermicast, also called worm castings,
worm humus or worm manure, is the endproduct of the breakdown oforganic
matter by an earthworm
16
TO DO
17
TO DO
18
LEARNING
ACTIVITY 11
PAGES 90 – 92
SHORT
QUESTIONS
THE END