Page 106 - General and Inorganic Chemistry for Advanced Secondary Schools Students Book Form Five and Six
P. 106
Biology for Secondary Schools
Exercise 5.6
1. Describe the distinctive features of
members of phylum Platyhelminthes.
2. Imagine you are conducting a
FOR ONLINE READING ONLY
laboratory investigation. In one
of your experiments, you come
across a specimen of a tapeworm.
What features will enable you
to tell whether the specimen is a Figure 5.28: Examples of nematodes (a)
tapeworm? ascaris (b) eelworm
3. Why is it not advisable to eat raw General characteristics of nematodes
or undercooked beef?
(a) They have round, cylindrical,
Phylum Nematoda elongated and unsegmented bodies
with pointed ends.
Task 5.12 (b) They depend on other organisms as
Search from reliable internet sources source of food.
the videos or images that show round (c) They have no blood circulatory
worms. system; therefore, transport is by
simple diffusion through the thin
Phylum Nematoda comprises round moist cuticle or through the fluid-
worms which are among the most filled body cavity.
numerous multicellular animals on the (d) Many species of nematodes are
earth. They inhabit a wide range of parasites of both animals and
environments, including soil, marine plants, but there are also many free-
and freshwater. Examples of nematodes living species found in marine and
include the animal parasites, such as freshwater sediments and in the
ascaris and plant parasites, such as soil.
eelworms. See Figure 5.28. (e) They are dioecious with separate
sexes. Males are usually smaller
than females.
100 Student’s Book Form One Student’s Book Form One
15/10/2024 09:24:34
Biology FORM 1 new.indd 100
Biology FORM 1 new.indd 100 15/10/2024 09:24:34
