Question

(i)
Many animals use Photoperiod as cues for timing their foraging, reproductive
and migratory activities.
(ii) Thermal tolerance determine geographical distribution of organisms
(iii) Green algae found in deepest water
(iv) The inhabitants of the deep oceans are much aware of the existence of Sun.
Incorrect statements are
1. (ii), (iii) & (iv)
2. (i),(ii) & (iv)
3. (iii) & (iv) only
4. (iv) only​

Answer 1

Answer:

i} Animals use seasonal variations in light intensity and photo period to time various activities. Birds of colder areas of Northern Hemisphere begin their Southward migration as the day lengths being to shorten. Reverse journey is undertaken with the increase in day length. Turkeys, ferrets and starlings greed in response to lengthening of days while goat, sheep and deer breed in response to shortening of days. Rabbits and guinea pig are day neutral.In temperate and subtropical areas, cold blooded or ectothermic animals undertake hibernation as the day tenth begins to shorter.

ii}The geographical distributions of different species of organisms depends on their thermal tolerance. Organisms which can tolerate a wide range of temperature variation ,e.g. most mammals and birds are called eurythermal organisms. The average temperature in tropical deserts in summer is more than500C . Thermal springs can sustain, where average temperature exceed 100Ci.e.,many microorganisms (e.g. some archaebacteria) live there.

iii} For sustaining life in the deepest waters, energy is necessary. Algae synthesize their food by using solar energy. At the bottom of deep water bodies, only high energy components of the solar spectrum are able to reach.  

The blue and green light components have short wavelengths and hence high energy. So, blue-green light reaches the bottom. This blue-green light is absorbed by the pigment phycoerythrin which is present in red algae. Hence, red algae is likely to be found in the deepest waters.

So, the correct answer is 'Red algae'.

Explanation: