Question

Which of the following is NOT a characteristic of deep diving mammals?

a. None of these is true of deep-diving mammals.

b. All of these are true of deep-diving mammals.

c. They shut down non-essential metabolic functions during dives.

d. They carry more oxygen in their lungs than humans do.

e. Their heart rate decreases dramatically during dives.

f. They carry more oxygen in their blood than humans do.

g. They can get the bends.

h. They are endothermic (homeothermic).

i. They can have large brains.

j. They carry more oxygen in their blubber than humans do?

k. Diving is generally an aerobic activity for them.

Answer 1

The followings are NOT a characteristics of Deep Diving Mammals :

d. They carry more oxygen in their lungs than humans do.

They do not carry oxygen in lungs because air filled lungs will show bouyancy which will make diving difficult.Before diving they exhales 90% of air so that the lungs does not collapse as air is easily compressed at high pressure.

They carry oxygen in their muscle and blood to make themselves active.They have more number of RBCs than humans which allow it to hold or store large amount of oxygen in it.They have a high blood to body volume ratio which helps them to survive deep under water.They also have high percentage of myoglobin in muscle which has higher affinity towards oxygen.

They also decreases their hearth rate as they come in contact with cold water,they show Bradycardia as their mammalian diving reflex.

g. They can get the bends.

Diving mammals generally do not get bends as the exhales most of the oxygen from lungs,so no air no problem,hence no decompression sickness.

j. They carry more oxygen in their blubber than humans do

The blubber is the layer of fat underneath the skin which by trapping air in between the fat layer insulates the marine mammals body and help maintaining body temperature deep inside sea where temperature is very low.

k. Diving is generally an aerobic activity for them.

It is an anaerobic activity for diving mammals.They exhales 90% of air from lungs and switch their body organs to anaerobic respiration.This a kind of adaptation which make them survive deep inside the sea for longer period.

Other options are the characteristics of diving mammals like they are endothermic(warm blooded animals),have larger brains,can  shut down non-essential metabolic functions during dives so that they can survive inside water for longer time and conserve energy.