13. Sheep & Cows have no upper
incisors, unlike horses:
Horny pad of gum
sheep
horse
14. Function of the horny pad on upper jaw:
the lower teeth grind against the horny pad to
cut grass.
15. Compare canines in herbivores and
carnivores
sheep
cow
Small as in sheep OR
absent as in cows:
no need to kill
Large, long and
pointed:
to kill prey & hold it
16. Diastema is a space where food
collects before being
pushed back by the tongue
17. Why are premolars & molars very
flat in herbivores?
Provide a large surface area
for crushing grass.
24. The lower jaw moves:
Carnivores &
Omnivores
Up and down
Herbivores
Sideways and
back and forth
25. Question: SEP, 2007
The following diagram shows
the skull of a lion.
a. List TWO characteristics of
canines visible in the
diagram. (2)
Long and pointed.
b. i) What are the canines used for? (1)
To hold the prey in place / tear flesh.
ii) What are the carnassials used for? (1)
Crush flesh and bones.
26. c. i) Explain why carnivores have a
proportionally large liver. (1)
Excess amino acids are deaminated in the
liver.
ii) In a carnivore the upper and lower jaw fit
together so closely that they cannot be
dislocated. Explain the benefit of this. (1)
So the jaw does not dislocate as the prey
struggles to become free.
27. d. i) In sheep a horny pad replaces the incisors and
canines on the upper jaw. Explain the function of
the horny pad. (1)
The lower teeth grind against the horny pad to cut
grass.
ii) In herbivores such as sheep the upper and lower
jaw fit loosely. What is the benefit of this?
To allow side to side movement during chewing. (2)
iii) Name the TWO types of teeth that herbivores use
to grind and chew the vegetation.
Molars and premolars. (2)
28. Question: MAY, 2010
Give a biological explanation for the following
statement:
The dentition of a rabbit is adapted to its diet. (5)
The front incisors are chisel-shaped and adapted for
cutting.
The molars and premolars have flat grinding surfaces
that continue to grow throughout life as they are worn
away by grinding.
The upper and lower jaw fit together very loosely to
allow side-to-side movement during chewing.
Diastema to enable manipulation of food.
Rabbit is a herbivore.
30. Most herbivores have a problem:
eat grass: principal component is cellulose
cannot produce cellulases
Mutualistic bacteria in digestive system
produce cellulases.
32. Fig. 3 A ruminant.
e.g. cow, sheep, goat, camel
a ruminant has a stomach made of four
chambers, the biggest being the rumen
33. Where are the bacteria able to make cellulase
found in rabbits & cows?
Non ruminants
Rabbit
Ruminants
Cow
34. The rumen contains mutualistic bacteria that
produce the enzyme cellulase.
35. A ruminant:
1. Cuts the grass and swallows it into the
rumen.
2. Bacteria in rumen make cellulase to digest
the cellulose.
3. The grass is regurgitated and chewed by the
flat molars and premolars.
36. Chewing the cud is when
the grass is regurgitated and chewed by the flat
molars and premolars
What’s up…I’m
chewing my
cud…Sometimes I
chew over 100 times
before swallowing!
A cow makes between
40,000-60,000 jaw
movements a day chewing
37. The length of the vertebrate digestive system is
related with diet.
Explain why, in
general herbivores &
omnivores have longer
alimentary canals
relative
to their body sizes
than carnivores.
38. A longer alimentary canal provides more:
1. time for digestion
2. surface area for absorption of nutrients.
Vegetation is more difficult to digest than
meat because it contains cells walls.
39. Question: MAY, 2012
The table below lists a number of characteristics
related to the dentition of dogs and a sheep. For
each statement in the tablemark the box with a
tick () if correct and a cross () if incorrect. (4)
STATEMENT
Incisors found on both upper and
lower jaws.
Molars wear down to form enamel
ridges.
Strong jaw muscles that allow
extensive chewing of food.
Jaw joint only allows up and down
movement.
DOGS
SHEEP
40. STATEMENT
Incisors found on both upper
and lower jaws.
Molars wear down to form
enamel ridges.
Strong jaw muscles that allow
extensive chewing of food.
Jaw joint only allows up and
down movement.
DOGS
SHEEP
41. Question: SEP, 2008
Give a biological explanation for each of the
following statements:
Sheep have cellulose-digesting bacteria in their
gut but lions do not. (4)
Sheep are herbivores and eat grass with a high
cellulose content. Bacteria produce cellulase to
digest cellulose.
Lions are carnivores and do not need the
bacteria.
