2. Animals
are multicellular organisms that feed
on other organisms
have a nervous system
usually move around
can be divided into:
1) INVERTEBRATES (have no backbone)
2) VERTEBRATES (have a backbone)
7. 3) NEMATODES (ROUNDWORMS)
have a long thread-like body,
round in cross-section
some live in the soil, but many Nematode in soil.
are plant or animal parasites
Nematodes damage
Nematodes inside a root.
potatoes.
8. e.g. Ascaris & pin worms
(live in human gut)
Ascaris: 25-40 cm long.
Ascaris block intestines.
Pin worms
9. 4) ANNELIDS (segmented worms)
long body divided by rings into a series of
segments
have a digestive tract with a mouth and anus
earthworm
leech
ragworm
11. 5) MOLLUSCS
body soft and
unsegmented, usually covered
by a shell
most have:
an external (e.g. snail, mussels)
or
internal shell (squid)
live in aquatic or moist environment
13. 6) ARTHROPODS
segmented animals with a hard exoskeleton
that is shed and replaced by a new one
when animal needs to grow
moulting is the shedding of the exoskeleton
28. 7. Spiracles on the thorax and abdomen.
Spiracle leads to the
spiracle
tracheal system.
29. Functions of the exoskeleton
1. It is hard and so protects the insect from
damage attack of microbes.
30. Functions of the exoskeleton
2. It is covered by a waxy
layer and so makes the
insect waterproof. Thus
insects can live in dry
places.
3. It provides a place where muscles can be
attached.
31. Development of insects
Metamorphosis:
is when an animal changes
its form
TWO types of
metamorphosis in insects:
Complete metamorphosis : 4 stages
Incomplete metamorphosis : 3 stages
32. Complete metamorphosis is when :
an insect undergoes a complete change
FOUR stages in life cycle: larva
larva pupa
e.g. housefly
mosquito
egg adult
butterfly
33. The larva & adult feed on different types of
food. How is this an advantage to the insect?
Adult feeds on nectar.
Larva eats grass.
Avoid intraspecific competition.
Occupy different niches.
34. Incomplete metamorphosis is when:
the insect develops gradually
THREE stages in life cycle:
e.g. grasshopper
beetles adult
egg
ladybirds
nymphs
Instars:
stages between moults
35. A nymph looks exactly like an adult but
has no wings
nymphs
adult
36. Why do you think that nymphs &
adults compete with each other?
Feed on the same
type of food and
occupy the same
niche.
Grasshopper nymphs.
Both have biting mouthparts.
37. Ecdysis or Moulting
is the removal of the exoskeleton from time
to time
happens to let the insect to grow
happens in the:
larva
nymph stage
BUT not in the adult
38. The Vertebrates have:
a vertebral column extending to form a tail
an internal skeleton, usually
made of bone
five classes:
1. Fish
2. Amphibians A shift from
3. Reptiles an aquatic to
4. Birds a terrestrial
5. Mammals habitat.
45. Question: MAY, 2011
Give a biological explanation for each of the
following statements.
Frogs have a moist skin. (5)
46. REPTILES
terrestrial ( live on land)
eggs:
laid on land
are protected by a soft shell
have a dry, waterproof, scaly
skin
e.g. lizard, crocodile, turtle, snake
47. BIRDS
feathers cover the body
eggs have a hard shell
have wings to fly
a toothless beak to feed
49. Question: SEP, 2004
Give biological explanations for each of the
statements:
Birds have hollow bones. (2)
To be light and so can fly.
50. Question: MAY, 2009
Give the biological explanation of each of the
following statements.
Birds are well adapted to move through the air.
(5)
51. Question: MAY, 2009
1. Have wings to fly.
2. Skeleton is lightweight due to hollow
bones.
3. Have a beak instead of teeth to be
lightweight.
4. Feathers cover the streamlined body to
reduce air resistance.
5. Tail helps to steer and brake.
52. Question: SEP, 2012
Hawks are bird species commonly
found in desert biomes. Explain why
some of the largest feathers are
attached to the wing. (2)
Large feathers are needed to
provide a large surface area to
flap the wings to provide lift.
59. The vertebrate classes can be:-
1. POIKILOTHERMIC (cold-blooded)
- cannot regulate their body temperature
- fish, reptiles & amphibians
2. HOMEOTHERMIC (warm-blooded)
- can regulate their body temperature
- birds & mammals
[NEVER USE cold and warm blooded in your
answers].
61. Fish, reptiles & amphibians are:
get heat from their surroundings
Convection
Radiation
Conduction
62. Birds & mammals are:
get heat from inside their body by:
respiration
muscle contraction
63. Question: MAY, 2010
Which property of birds
allows them to incubate
eggs? (2)
Have feathers that
makes them keep a
constant body
temperature.
They are
homeothermic.
64. Advantages of being endotherms:
animal is active all the time and all year
round:
so can escape predators
search for food more efficiently
immune
system works
well
65. Question: SEP, 2006
Give ONE structural difference to distinguish
between:
a) an insect and an arachnid (1)
Insect: 3 body parts/ 6 legs/ compound eyes
Arachnid: 2 body parts/ 8 legs / no compound eyes
b) a fish and a reptile (1)
Fish: moves by fins / has gills to breathe
Reptile: moves by legs / lungs to breathe
66. Question: SEP, 2007
Give THREE characteristics of EACH of the
following groups of organisms:
a) annelids; (3)
long body divided by rings into a series of
segments
have a digestive tract with a mouth and
anus
move by bristles
67. Question: SEP, 2007
Give THREE characteristics of EACH of the
following groups of organisms:
b) arthropods. (3)
segmented animals
body is covered by an exoskeleton which is
shed by moulting
have jointed limbs