This document summarizes the biological clock in animals. It defines the biological clock as an innate, automatic rhythm that organisms use to measure time. It classifies biological clocks into 5 main types: circannual (annual), circatidal (tidal), circatunal (lunar), circasyzygic (related to syzygy or alignment of sun, moon, earth), and circadian (daily). The circadian clock controls daily rhythms in many animals corresponding to periods of activity at sunrise/sunset or night versus day. Understanding biological clocks helps humans know when animals will be most active, and aids activities like fishing and agriculture.

1. Uttam memorial College raigarh
SUBJECT – ANIMAL BEHAVIOUR
TOPIC – BIOLOGICAL CLOCK
Guided By
Miss Daya mahant mam
Of zoology department
Submitted By
Nikita Jaiswal
M.Sc. Zoo. 1st sam

2.  Synopsis:-
 Introduction
 What is biological clock
 Classification of biological clock
 Circannual clock
 Circadian clock
 Conclusion
 Reference

3.  Introduction:-
 There has been evidence for a long time and in the
word that there are difference type of rhythms.
 1980 “Charles Darwin” has taken that changing is
found in many animals which plants and animals,
rhythms to some extent genetic based.
 Rhythm is more in plants than in animals because the
day of animals is more initiative than that of plants.
 Rhythmic events in the atmosphere at night it occurs.

4. Defination:- In the early times (Erwin 'Bunning’) discribed
did very unique work on biological clock and in 1986 he
suggested that organism have an inbuilt and almost
automatic rhythm which has to repeat itself in an
interval time.
This rhythm is useful in the measurements of time.
Biological clocks is also known as biological rhythm.

5.  Classification of biological clock:-This are mainly 5 type classified of
biological clock:-
1. Circannual clock
2. Circatidal clock
3. Circatunal clock
4. Circasyzygic clock
5. Circadian clock

6.  Circannual clock:- Such activities of plants or animals,which are affected
by the season and happen once a year, annual clock is controlled by, this
called is Circannual clock.
Example:-
1. Those who are interested in baravani know that some flowers bloom only
summer,Pansy, Calendula flower in Candipter and Carnation etc,come out
in centuries because these plants flowering is affected by day time.
2. Birds and some animals is adapted and protection for climatic conditions
and search of food they are migrate in your specific place.

7.  Circadian clock:- Some animals in these cycle are most active at the time of
sunrise and sunset and such animals are called Crepuscular.
 There are some animals,which remain active in the night,it is called
Nocturnal.
 Some animals remain active during the day,they are called Diurenal.
Example:-
In the few experiment,the soldiers were taught to spin the wheel during the
night and to rest at night.
Therefore it was kept in continuous darkness.
It was found from the analysis that the timing of winding and closing was
accurate.

8.  Conclusion:-
 By understanding biological clocks,man has been able to know it’s various
applications.
 Hunter know when an animal will be most active.
 Fisherman know the exact time to catch sea worms, specially crabs,
grunion,pelali and other worms.
 Former known as that, which fruits will grow in which season and what
are the flowers and vegetables of summer or winter.

9.  Refrence:- By animal behaviour book:- “Reena Mathur”