Biological Rhythms

Question 1

Biological Clock

Answer 1

an innate mechanism that controls the physiological activities of an organism which change on a daily, seasonal, yearly, or other regular cycle.

Question 2

Circadian

Answer 2

24 Hours
recurring naturally on a twenty-four-hour cycle, even in the absence of light fluctuations. e.g Diurnal, Nocturnal, Crepuscular, Arrythmic(lacking rhythm – eg caves), Human

Question 3

Circannual

Answer 3

365 days
having, characterized by, or occurring in approximately yearly periods or cycles (as of biological activity or function)- often seasonal

Question 4

Circatidal

Answer 4

12.4 hours
A circatidal rhythm is a rhythm or pattern of behavior that repeats approximately in concert with one tidal cycle

Question 5

Circalunar

Answer 5

29 days
A biorhythm that corresponds with the lunar cycle
Very high/low tides may signal reproductive activity

Question 6

Crepuscular

Answer 6

those that are active primarily during twilight (i.e., dawn and dusk).
Crepuscular animals are active not in daytime, nor nighttime, but at twilight -cats are actually crepuscular. Which is why kitty gets so finnicky at 5am and 8pm roughly

Question 7

Daily Rhythm

Answer 7

Circadian rhythm

Question 8

Diurnal

Answer 8

Diurnal Animals (Animals awake, hunting, gathering, etc during the hours where the sun illuminates that area of the globe) – birds, (most, humans)

Question 9

Nocturnal

Answer 9

(Animals awake, hunting, gathering, doing actions at night, during hours where the sun’s light is not visible on that part of the globe)

Question 10

Endogenous Rhythms

Answer 10

Endogenous rhythms are set by an internal clock. They will persist even in the absence of environmental cues

Question 11

Exogenous Rhythms

Answer 11

Exogenous rhythms are imposed on the organism by the external environment.

These external cues are known as zeitgebers (time givers).
Pacemakers Exogenous Zeitgebers

Question 12

Entrainment

Answer 12

is the resetting of the biological clock on a regular basis, forcing it to take up the period of the environment. This is done with a zeitgeber.

Question 13

Zeitgeber

Answer 13

Zeitgebers are events that keep our circadian rhythms regulated. The alternation of the light/dark cycle of a 24-hour day is the most important natural zeitgeber.

Without the environment to act as a zeitgeber, a free-running rhythm gets progressively more out of step with the external environment.

Question 14

Free running

Answer 14

A rhythm that continues under constant conditions is said to be free running
Free running means the period( time it takes between successive peaks of activity) does not correspond exactly within the period of environmental rhythm.