Exercise 1. Use the following table to speak about cestodes, trematodes and nematodes.

	Cestodes	Trematodes	Nematodes
Shape	Tape-like, segmented	Leaf-like, unsegmented	Elongated, cylindrical, unsegmented
Head end	Suckers present; some have hooks	Suckers present, but no hooks	Hooks and suckers absent. Well-developed mouth with teeth or cutting plates
Alimentary canal	Absent	Present but incomplete, no anus	Complete with anus
Body cavity	Absent	Absent	Present
Sex	Not separate: hermaphrodite	Not separate: hermaphrodite	Separate: male and female
Life cycle	Requires 2 host	Requires 3 host	Requires 1 host

 

Exercise 2. Complete the following sentences. Choose the ending according to the text.

1. Helminths are multicellular invertebrates, which live ….

2. Anatomically, cestodes are divided into …

3. Trematodes are hermaphroditic, which means that ….

4. Helminths exist in three forms: ….

5. Some helminthes can complete development only on particular host species, which make them ….

6. The name of worm infection is ….

7. Worms can cause productivity losses in livestock, such as ….

Exercise 3. Match the term with its definition.

helminth	an organ that helps an animal to stick to a surface
intermediate host	the state of being invaded by parasites
sucker	the immature form of most invertebrates which must metamorphose
fluke	someone who is trying to win or to do better than all others
larva	thehostinwhichaparasiteundergoesdevelopmentbutdoesnotreachsexualmaturity
infestation	periodic replacement of an outer layer
competitor	parasitic worm
molt	parasitic unsegmented flatworm

Exercise 4. Choose the most appropriate word from those given in brackets.

1. Flukes (occur, possess, get, produce) an alimentary canal, but it is incomplete. 2. Obligate parasites cannot (have, develop, possess, complete) their life cycle without spending some time on their (master, host, owner, boss). 3. The majority of nematodes have (straight, complete, direct, simple) life cycles. 4. Inside their (neutral, intermediate, middle, unsuited) host worms complete certain development stages. 5. Knowledge of the life cycle is very important for (operating, making, creating, establishing) preventative measures. 6. Some worms can be very (beneficial, poor, harmless, harmful) for their facultative host. 7. Healthy animals often (support, tolerate, digest, allow) considerable worm numbers without developing a disease.

 

Exercise 5. a) Make up collocations using the words from both columns.

flattened	system
reproductive	life cycle
alimentary	growth
direct	response
insufficient	body
impaired	organs
immunological	conditions
ecologic	fertility

 

b) Fill in the gaps with the words from the table above.

1. Cestodes have tape-like, ….

2. Flatworms possess both male and female … in the same individual.

3. Roundworms have a relatively well-developed …, with mouth and anus.

4. … is characteristic of many nematodes.

5. The examples of productivity losses in livestock are … and ….

6. The symptoms of worm infection, among other factors, depend on … of the animal involved.

7. The duration of each development stage vary with ….

 

Exercise 6. Translate the following words and phrases into English.

Пищеварительный тракт; облигатные паразиты; достигать зрелости; вылупляться; подвергаться превращениям; прямой и непрямой жизненные циклы; окончательный хозяин; промежуточный хозяин; недостаточный рост; сниженная плодовитость; линька; ротовые присоски; прочная оболочка; стадия развития; значительное количество; двуполый; профилактические меры; оставаться жизнеспособным.

 

Exercise 7. Give the English equivalents of the Russian words in brackets.

1. Cestodes lack (пищеварительнаясистема), and nutrients (всасываться) through the body covering. 2. Nematodes (различатьсявзависимостиотвида) from a few mm to more than 50 cm in length. 3. Most nematode species form two (отдельный) sexes, with (мужскиеиженскиеособи). 4. Helminths cannot (завершитьжизненныйцикл) without spending some time on their host. 5. Typical for flukes and tapeworms (непрямойжизненныйцикл) require one or more (промежуточныйхозяин) in addition to the (окончательныйхозяин). 6. Some parasitic worms are (угрожающиежизни) for livestock and pets, other species are well tolerated by their hosts without (очевидныйущерб).