Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Minor Phyla > Gnathostomata > Flashcards

Gnathostomata Flashcards

1
Q

Give the 3 top level groupings contained within this super class.

A

Placodermi
Chondrichthyes
Teleostomi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which species within this group are extinct in the modern day ?

A

Placodermi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Give the basic features of the Placodermi.

A

Dorso-ventrally flattened
Armoured skin, mineralised so very heavy
Benthic feeder.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Give the 2 classes found within the extant Chondrichthyes

A

Holocephali

Elasmobranchi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Give the main species found within the holocephali.

A

Chimaeriformes, Ratfishes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe an adaption of the ratfishes scales

A

They are placoid, homologous to vertebrate teeth.

Have a layer of dentine and enamel.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Give the characteristics of Elasmobranches.

A

5 to 7 gill clefts
Rigid dorsal fins
Small placoid scales

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Give examples of species found in this class.

A

Rays, Sharks, Sawfish

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe what would happen if there was no osmoregulation in elasmobranchs.

A

Salt water has a higher molarity than blood. If left unchecked water would diffuse out and ions flow in.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is water retained within the elasmobranch ?

A

Utilise ion pumps in gills and rectal gland to excrete excess ions
Concentrate Urea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the osmoregulation of a sawfish

A

Derived ray, freshwater habitat.

Therefore has low blood ion concentrations and low urea to excrete as much water as possible.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe some of the elasmobranchs sensory adaptions.

A 
Vision- Tapetum (reflective tissue in eyes)
Hearing 
Lateral line
Notice chemical changes 
Passive electroreception
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the process of detection via Lateral line

A

Line of pores on outside of the fish
Vibrations in the water enter line and shake cupula.
This gives the fish sensory awareness.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is passive electroreception ?

A

The elasmobranch cannot generate electric fields but can detect those generate by other animals.
this enables detection in the dark.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Give the 3 forms of elasmobranch reproduction

A

Oviparity
Viviparity
Ovoviviparity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Nearly all skates and some sharks reproduce via…

A

Oviparity
The eggs are laid and develop outside the female
(mermaids purse)

17
Q

All rays and some sharks reproduce via…

A

Viviparity

Internal brooding, A yolk sac placenta is present which enables transfer of nutrients

18
Q

Most sharks reproduce via…

A

Internal brooding, No transfer of nutrients (yolk only)

19
Q

Describe the cannibalism that can occur between shark embryos.

A

In some sharks, embryos will eat other eggs lain as a form of nutrition.

20
Q

Describe the process of serial tooth eruption in sharks

A

Have several rows of continually growing teeth.

The new teeth will form inside the jaw, tilting forward when ready to appear in the jaw line.

21
Q

What is the advantage of serial tooth eruption ?

A

Enables the tooth to grow faster and in the protection of the jaw

22
Q

Sharks have a spiral intestine, why is this advantageous ?

A

Enables rapid absorption and re-absorption of food. increasing efficiency.

23
Q

Give the means of respiration in a shark.

A

5 gills

Spiracle

24
Q

What problems do sharks face when generating buoyancy ?

A

They live in marine environments

sea water is more dense than freshwater so requires greater generation of lift

25
Q

How do sharks generate buoyancy ?

A

Lift from Heterocercal tail
Lift from liver oils (squalene. less dense than water)
Lift from pectoral fins
Large liver (25% of body mass) aids flotation and food storage

26
Q

Describe a key adaption of shark jaws

A

Able to retract and push forward jaws

Enables increase in size of jaws on demand

27
Q

How does fertilisation take place in sharks ?

A

Internal fertilisation

Males have claspers to grasp female

28
Q

What are male claspers modified from ?

A

Pelvic fins

29
Q

Describe an adaption of a rays pectoral fins

A

They have evolved into wings, increasing mobility

30
Q

Why are rays required to constantly move ?

A

To maintain constant water flow over the gills.

Minor Phyla (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions