Year 11 Human Biology
Unit 7 - The Primates
Study Questions - Solutions
1. List the characteristics all primates have in common with mammals.
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Notocord
Nerve Cord
Pharyngeal slits
Post anal tail
hair
homiothermic
4 chambered heart
development of the young in the uterus
mammary glands.
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2. List the features that all primates have in common.
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Unspecialized mammalian body
Pentadactyl limb
Nails instead of claws
Forward facing eyes
Declined sense of smell
4 Incisors
Increased brain size
Evolutionary trend in reproductive behavior and strategies
Increases use of facial expressions.
3. Describe and contrast the social hierarchy that exists within the higher primates
such as the baboon troop and orangutans.
The orangutans live a solitary life only coming together for mating where the baboons live in a
dominace heirarchy which is lead by a single male, who has reproductive rights over the females.
4. Why is the tree shrew considered to be a primitive primate and the ancestor to all
primates?
Because it has a small brain, long pointed snouts, claws, not nails, and have sideways partly looking
eyes.
5. Describe the three major types of locomotion within the primates.
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Quadrupedal means walking on all four legs
Brachiation means swinging through the trees.
Bipedal means walking on two legs.
6. Describe several structural differences between old world and new world
monkeys.
The difference between OWM and NWM is the OWM possess ischial callosities, a non-prehensile tail
and widely separated nostrils. The NWM do not possess ischial callosities, have a prehensile tail and
downward facing nostrils.
7. Describe how new world monkeys were thought to have evolved.
By island hopping to the New World when the distance was only 400 - 800 kms.
8. List the major types of primates that are:
• Prosiminans
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Tarsiers
Lemurs
Lorises
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New World Monkeys
Old World Monkeys
Hominiods
Anthropoids
9. What is the advantage of the opposable thumb?
The ability to move the thumb so it can touch all the other digits.
10. Draw a simplified classification of the primates that includes order, suborder,
infraorder, superfamily and family.
Order
Suborder
Infraorder
Superfamily
Family
Lemurs
Prosimians
Loris
Tarsiers
Primates
Cebidae
Platyrrhines
Ceboidea
Callitrichidae
Anthropoids
Cercopithecoidea
Cattarrhines
Cercopithecidae
Hylobatide
Hominoidea
Pongidae
Hominidae
11. Define the term prehensile and what is the advantage of a prehensile tail.
A prehensile tail means it has the ability to grasp onto trees etc. The advantage is it frees up limbs for
feeding
12. Describe some of the anatomical differences that occur between quadrupeds,
brachiators and bipedal primates.
Some of these include for quadrupedalism:
• Short clavicle and scapula
• Compressed rib cage
• Larger lumbar gap (All for increase speed)
For brachiation:
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Long arms and fingers
For Bipedalism:
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Posterior scapula
Thick weight bearing vertebrae
Flared, bowl shaped pelvis
Wide sacrum
13. What features do humans have that differ from other primates.
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Stance & Locomotion
The human hand
The brain
Dentition
Speech
Body Covering
Sexual Characteristics
Care of the young
14. What does arboreal mean and describe some of the features these primates have.
Arboreal means living in the trees and some of the features include one claw for gripping, Long
forelimbs, long forearms.