Specialised Senses

Question 1

What animal has a bill?

Answer 1

a duck-billed platypus

Question 2

What texture is the bill?

Answer 2

soft and flexible

not hard and rigid like a duck’s

Question 3

Why does the platypus rely on it’s bill?

Answer 3

animal feeds mainly at night on aquatic invertebrates foraging for them on the bottom of rivers and streams

it closes it’s eyes, ears and nose whilst hunting, relying on it’s bill to detect obstacles and find prey

Question 4

What does the bill have that allow the animal to feel it’s way and detect currents in the water?

Answer 4

tens of thousands of mechanoreceptors which respond to normal gentle touches or pressure

Question 5

Where is the duck-billed platypus native to?

Answer 5

eastern and south eastern Australia

Question 6

What is the lateral line?

Answer 6

an organ that allows fish to detect the movement of water

Question 7

What does the lateral line consist of?

Answer 7

a series of openings running down the length of the skin all connected to the lateral line canal

Question 8

What are the sense organs themselves in a lateral line?

Answer 8

neuromasts which are hair-like projections which extend into the canal and move with the movements of water in the canal

Question 9

How does the lateral line allow the brain to register and respond to the movements of water around the fish?

Answer 9

movements of the neuromasts generate electrical signals in the nerve cells to which they are attached

these electrical signals then travel through the nervous system and to the brain

Question 10

What are vibrissae?

Answer 10

special hairs whose only function is to provide sensory tactile information

Question 11

What does the lateral line allow a fish to do?

Answer 11

detect prey

avoid predators

swim together in schools

Question 12

What are the most well-known vibrissae?

Answer 12

whiskers

Question 13

What provides animals with further sensory clues about their surroundings?

Answer 13

the root hair plexus associated with whiskers

Question 14

How is a star-nosed mole adapted to living underground?

Answer 14

it’s nose has a highly developed sense of touch

the nose has tens of thousands of tactile receptors so it can quickly understand it’s environment and find prey

Question 15

What is the Jacobson’s organ

Answer 15

a specialised organ that forms part of the olfactory systems in many reptiles and mammals

Question 16

Where is the Jacobson’s organ located?

Answer 16

in the hard palate under the nasal cavity

Question 17

What can the Jacobson’s organ do?

Answer 17

it can detect specific chemical compounds normally related to pheromones or the scent of prey or predators

Question 18

Where does the signals from the Jacobson’s organ go to?

Answer 18

signals from Jacobson’s organ are sent via a second olfactory bulb called the accessory olfactory bulb to the hypothalamus

Question 19

Why does the Jacobson’s organ have a complimentary role to the main olfactory system?

Answer 19

because the main olfactory system is able to detect chemicals that easily evaporate into a gas

Jacobson’s organ can analyse chemicals which do not easily evaporate into a gas and remain in the form of a liquid

Question 20

What are chemicals that easily evaporate into a gas known as?

Answer 20

volatile compounds

Question 21

What are chemicals that do not easily evaporate into a gas and remain in the form of a liquid known as?

Answer 21

non-volatile compounds

Question 22

What is the flehmen response?

Answer 22

when an animal curls their top lip and stretch their neck

Question 23

What is the flehmen response used for?

Answer 23

to expose their Jacobson’s organ to smells

Question 24

What are electroreceptors?

Answer 24

a type of sensory receptor that responds to the presence of electric fields

Question 25

Why have electroreceptors evolved?

Answer 25

electrical signals are continuously being sent around and between the nervous system and the brain

in aquatic environments this generates a small electrical current in the water

electroreceptors detect this current which is a signal that a living creature is nearby

predators can use electroreceptors to detect the presence of prey

Question 26

Why have electroreceptors only evolved in aquatic animals?

Answer 26

water allows electrical currents to flow through it

electrical currents cannot flow through air

Question 27

What are ampullae of Lorenzini?

Answer 27

an electroreception organ that is found in cartilaginous fish such as rays, skates and sharks

Question 28

How do animals use their ampullae of Lorenzini?

Answer 28

the ampullae of Lorenzini consists of a series of pores that appear on the surface of the skin

each pore is connected to a tube, filled with a gel that conducts electricity which ends in a pouch called an ampulla

ampulla is connected to nerves which sends signals to the brain

Question 29

What other animal has electroreceptors?

Answer 29

duck-billed platypus

Question 30

What does the duck-billed platypus use their electroreceptors for?

Answer 30

to locate prey when foraging at the bottom of rivers and streams

Question 31

Where are electroreceptors located on a platypus?

Answer 31

on the bill

Question 32

What animals is echolocation used by?

Answer 32

bats to navigate and hunt at night

dolphins to navigate and hunt in murky or deep waters where light barely penetrates

Question 33

What is high-pitched sound called?

Answer 33

ultrasound

Question 34

How do dolphins use echolocation?

Answer 34

dolphins make high-pitched clicks

the sound travels in relatively straight lines and if it hits an object it is reflected back to the dolphin as an echo

this echo causes the dolphin’s lower jaw to vibrate

the jaw is connected to the animal’s ears and in this way the dolphin hears the reflected sound

Question 35

How do bats use echolocation?

Answer 35

bats emit high-pitched screams

the sound travels in relatively straight lines and if it hits an object it is reflected back to the bat as an echo

their specially adapted ears allow them to detect tiny differences between the original sound and the echo

this allows them to build up a detailed picture of their environment

Question 36

How can dolphins detect objects that are further away?

Answer 36

some travel faster in water than in air

Question 37

What are some examples of other animals that use echolocation?

Answer 37

sperm whales, oilbirds and common shrews but their use of the system is less sophisticated than in dolphins or bats