If he does not draw pictures he will fail the exam

Firstly: 

Drawing animate beings
such as people and animals is haraam, and is in fact a major sin. We have
already quoted the evidence for that in question no.

7222.
We have also stated in question no.
9473that if a picture is drawn without the head, then it is no longer
haraam. 

Secondly: 

If a student is required to draw something and he is able to
draw a permissible image, then he should do that. In this case it is not
permissible to draw a haraam image. Examples of permissible images include
trees, rivers and other inanimate things, or he can draw people without
heads. 

Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) was
asked: 

Some students have to draw some animals for the purpose of
study. What is the ruling on that? He replied: 

It is not permissible to make images of these animals because
the Prophet (peace and blessings of Allaah be upon him) cursed the
image-makers and said: “The most severely punished of the people on the Day
of Resurrection will be the image-makers.” This indicates that making images
is a major sin, because this curse only applies to major sins, and the
warning of severe punishment only applies to major sins. But it is possible
to draw part of the body such as a hand or foot, etc, because these parts
cannot live independently, and the apparent meaning of the texts is that
what is forbidden is that which could live (independently), because the
Prophet (peace and blessings of Allaah be upon him) said in some
ahaadeeth: “He (the image maker) will be told to breathe life into it and he
will not be able to do so.” 

Fataawa Ibn ‘Uthaymeen, 2/272. 

He also said: 

If a student is told to draw and has no other option, then he
should draw an animal without a head. 

Fataawa Ibn ‘Uthaymeen, 2/274,
272 

Thirdly: 

If a student is obliged to draw a complete picture, and not
doing so may cause him to fail, then Shaykh Ibn ‘Uthaymeen said: 

If this is the case then the student may regarded as being
forced to do this thing, so the sin will be on the one who told him to do
that. But I hope that those in charge will not go to this extent and force
the slaves of Allaah to disobey Allaah. 

Majmoo’ Fataawa Ibn ‘Uthaymeen,
2/274 

And Allaah knows best.