Question

Question 9

9-Hemoglobin is to mammals as _____________________________is to Arthropods.

Group of answer choices

1-hemocyanin

2-hemorythrin

3-hemoglobin

4-chlorocruorin

Question 10

10-All of the following characteristics are shared by Chordates except:

Group of answer choices

1-hollow dorsal nerve chord

2-pharyngeal gill slits

3-Internal bony skeleton

4-post anal tail

Answer 1

Answer to Question No 9 : 1) Haemocyanin

Explanation :

Blood in mammals contains red blood cells which contains a red pigment called haemoglobin which is responsible for the transport of oxygen to tissues and cells of the body. Similarly in arthropods, haemolymph is present which is analogous to blood in mammals. This haemolymph is present in haemocoel of the animals body and surrounds all the cells. Haemocyanin is present in haemolymph which is a copper based protein and is blue in Colour when oxygenated and this gives blue Colour to the lymph but when the haemolymph is not oxygenated, it looses it's Colour. So basically hemocyanin is present in arthropods instead of haemoglobin.

Answer to Question No 10 : 3)

Explanation :

All the chordates share four characteristics which may be present in only embryonic stage in some of them. Those four common features are as following :A dorsal hollow nerve cord

• Notochord
• Dorsal hollow nerve cord
• Pharyngeal slits
• Post anal tail

Notochord is responsible for providing skeletal support to the and it gives the name of chordates. In some it's developed into vertebral column and they are called as vertebrates.

Dorsal hollow nerve cord is derived from the ectoderm and develops into brain and spinal cord which makes up the central nervous system.

Pharyngeal slits are openings in the pharynx and these are only present in embryonic stage in terrestrial animals such as birds and mammals but in aquatic animals, it works to filter out water that comes with food.

Post anal tail extends beyond posteriorly. It's vestigial in humans and is only present in embryonic stage.

So all of these are common to chordates but not all chordates have an internal bony skeleton, some of them have cartilaginous endo skeleton like cartilaginous fishes which are also chordates.