Primates and Mammals

Question 1

What are the defining characteristics of mammals?

Answer 1

Hair, mammary glands, heterodont thecodont teeth, epiphyses on bones, diaphragm, 4-chambered heart, homeothermy (ca. 37°C).

Question 2

What is the primary and secondary function of mammalian hair?

Answer 2

Primary: insulation. Secondary: camouflage, signalling, sensory functions.

Question 3

What types of mammalian teeth exist?

Answer 3

Incisors, canines, premolars, molars—heterodont and thecodont.

Question 4

What respiratory adaptation do mammals have?

Answer 4

Diaphragm enabling efficient aspiration-based breathing.

Question 5

How does the mammalian heart differ from amphibians and reptiles?

Answer 5

Mammals have a four-chambered heart that separates oxygenated and deoxygenated blood.

Question 6

What are the main subclasses and infraclasses of mammals?

Answer 6

• Prototheria: monotremes (egg-laying mammals)
• Theria:
• Metatheria: marsupials
• Eutheria: placental mammals

Question 7

What are monotremes? Give examples.

Answer 7

Egg-laying mammals with cloaca and sprawling gait (e.g. platypus, echidnas).

Question 8

What are marsupials?

Answer 8

Mammals with short gestation; young develop in a pouch (e.g. kangaroo, koala, Tasmanian devil)

Question 9

Name some marsupial orders

Answer 9

Didelphimorphia (opossums), Diprotodontia (koalas, wombats), Dasyuromorphia (carnivores), etc.

Question 10

What defines eutherian mammals?

Answer 10

Bear live young nourished via a placenta; includes nearly 5000 species across 20 orders.

Question 11

Which order contains the most mammal species?

Answer 11

Rodentia (~2000 species).

Question 12

Which mammal order is capable of true flight?

Answer 12

Chiroptera (bats).

Question 13

What are carnassial teeth?

Answer 13

Modified premolars and molars in carnivores used for shearing flesh.

Question 14

Difference between Artiodactyla and Perissodactyla?

Answer 14

Artiodactyla: even-toed ungulates (e.g. deer, pigs); ruminants.
Perissodactyla: odd-toed ungulates (e.g. horses, rhinos); hindgut fermenters

Question 15

What are Cetaceans and their closest land relative?

Answer 15

Whales, dolphins, porpoises; closest relative is the hippopotamus.

Question 16

What was the Great American Interchange?

Answer 16

Movement of fauna between North and South America via the Isthmus of Panama ~3 MYA.

Question 17

What are the defining features of primates?

Answer 17

Forward-facing eyes, grasping hands/feet, large brains relative to body size, flat nails instead of claws, and typically a single offspring per pregnancy.

Question 18

What is binocular vision and why is it important in primates?

Answer 18

Overlapping fields of view from forward-facing eyes enable depth perception—key for navigating complex arboreal environments.

Question 19

What adaptations support grasping in primates?

Answer 19

Opposable thumbs and big toes (except in humans), flat nails, and sensitive pads on fingers and toes

Question 20

How are primate brains adapted?

Answer 20

Enlarged brain size, particularly in areas for social behaviour, learning, and sensory processing—supports complex cognition and behaviour

Question 21

What are the two major suborders of primates?

Answer 21

1. Strepsirrhines – “wet-nosed” primates (e.g. lemurs, lorises)
2. Haplorhines – “dry-nosed” primates (e.g. monkeys, apes, humans)

Question 22

What characterises Strepsirrhines?

Answer 22

Reliance on smell, smaller brain, grooming claw, more primitive features, and mostly nocturnal.

Question 23

What characterises Haplorhines?

Answer 23

Larger brains, flatter faces, more vision-dependent, and include monkeys, apes, and humans

Question 24

What are the two groups within Anthropoids (Haplorhines)?

Answer 24

• Platyrrhines (New World Monkeys): flat noses, prehensile tails
• Catarrhines (Old World Monkeys and Apes): downward-facing nostrils, no prehensile tails

Question 25

What distinguishes apes from monkeys?

Answer 25

Apes lack tails, have larger brains, and more flexible shoulder joints for brachiation or upright posture.

Question 26

Which primates are considered "great apes"?

Answer 26

Orangutans, gorillas, chimpanzees, bonobos, and humans.

Question 27

Which primate is most closely related to humans?

Answer 27

Chimpanzees and bonobos share ~98–99% of human DNA.

Question 28

What behavioural traits are common in great apes?

Answer 28

Tool use, social learning, communication (gestures, vocalisations), and complex social structures

Question 29

What is the significance of primate sociality?

Answer 29

Living in groups enhances protection, resource access, and learning—social bonds critical in primate evolution.

Question 30

What are Strepsirrhines and what are their key characteristics?

Answer 30

Strepsirrhines = "wet-nosed" primates (e.g., lemurs, lorises, galagos). Traits include: * Strong reliance on olfaction (smell) * Smaller brains relative to body size * Nocturnal, with a reflective eye layer (tapetum lucidum) * Tooth comb for grooming * Often have a grooming claw * Found in Madagascar (lemurs) and parts of Africa and Asia (lorises and galagos)

Question 31

What are Lemurs and where are they found?

Answer 31

Lemurs are endemic to Madagascar and range from tiny mouse lemurs to large ring-tailed lemurs. * Arboreal and terrestrial species * Mostly herbivorous or omnivorous * Exhibit seasonal breeding * Important ecologically as seed dispersers and pollinators

Question 32

What are Lorisiformes (lorises and galagos)?

Answer 32

* Lorises (Asia): Slow, stealthy climbers; toxic bite in some species * Galagos (Africa): Also called bush babies; fast, leaping locomotion * Both are nocturnal, arboreal, and have strong grip and grooming claws

Question 33

What are Haplorhines and how do they differ from Strepsirrhines?

Answer 33

Haplorhines = "dry-nosed" primates (e.g., monkeys, apes, humans, tarsiers) * Better vision: forward-facing eyes, color vision * Larger brain-to-body ratio * Mostly diurnal (active during day) * No grooming claw or tooth comb

Question 34

What are Tarsiers and why are they unique?

Answer 34

Tarsiers are small, Southeast Asian primates with traits of both strepsirrhines and haplorhines: * Huge eyes (for nocturnal vision), rotate head like owls * Long tarsal (ankle) bones for leaping * Only fully carnivorous primates (insectivores) * Classified as haplorhines due to genetic and brain structure similarities

Question 35

What are Platyrrhines and where are they found?

Answer 35

New World monkeys, native to Central and South America * Flat noses with side-facing nostrils * Prehensile tails in some (e.g., howler, spider monkeys) * Strictly arboreal * Include capuchins, tamarins, marmosets, squirrel monkeys

Question 36

What are key features of Platyrrhines (New World monkeys)?

Answer 36

* Smaller body size * Mostly herbivorous or frugivorous * Some species live in polyandrous groups (e.g. tamarins) * Use tails like fifth limb for balance and grasping

Question 37

What are Catarrhines and where are they found?

Answer 37

Old World monkeys and apes, native to Africa and Asia * Downward-facing nostrils * No prehensile tails * Larger body size * Includes Cercopithecoidea (monkeys) and Hominoidea (apes and humans)

Question 38

What defines Cercopithecoidea (Old World monkeys)?

Answer 38

* Long snouts, narrow nasal openings * Bilophodont molars (two ridges for grinding) * Some species have cheek pouches * Examples: baboons, macaques, colobus monkeys, langurs

Question 39

What defines Hominoidea (apes and humans)?

Answer 39

* No tails * Larger brains * Brachiation (arm-swinging in gibbons), knuckle-walking (gorillas, chimps) * Complex social systems, tool use, self-awareness * Includes gibbons, orangutans, gorillas, chimpanzees, bonobos, and humans

Question 40

How do Great Apes differ from Lesser Apes?

Answer 40

Great Apes: Larger, more intelligent (gorillas, chimps, bonobos, humans, orangutans) Lesser Apes: Smaller, more agile brachiators, highly monogamous (e.g., gibbons)

Answer 41

* Great Apes: Larger, more intelligent (gorillas, chimps, bonobos, humans, orangutans) * Lesser Apes: Smaller, more agile brachiators, highly monogamous (e.g., gibbons)

Question 42

What is the genus of modern humans?

Answer 42

Homo

Question 43

What species do modern humans belong to?

Answer 43

Homo sapiens

Question 44

What are key traits that distinguish humans from other apes?

Answer 44

* Bipedalism * Large brain relative to body size * Use of complex language * Advanced tool use and culture

Question 45

What was one of the earliest bipedal hominins?

Answer 45

Australopithecus afarensis (e.g., "Lucy") – lived ~3.9–2.9 million years ago.

Question 46

Which species is known for making and using tools and is considered part of the Homo genus?

Answer 46

Homo habilis – "handy man", ~2.4–1.4 million years ago.

Question 47

Which hominin species was first to leave Africa?

Answer 47

Homo erectus – widespread across Africa, Asia, and possibly Europe.

Question 48

What species is closely related to Homo sapiens and interbred with them?

Answer 48

Homo neanderthalensis (Neanderthals)

Question 49

What traits are associated with Homo sapiens' success?

Answer 49

* Complex language * Symbolic thought (e.g. art, burial) * Cultural transmission and innovation * Long childhood learning period

Question 50

When did Homo sapiens first appear?

Answer 50

~300,000 years ago in Africa