Timing Responces

Question 1

Actogram

Answer 1

Diagram showing the periods of activity and rest of an organism over a number of 24 hour periods so their trends in activity can be identified

Question 2

Annual rhythm

Answer 2

A rhythm or cycle occurring on a yearly basis

Question 3

Biological clock

Answer 3

An endogenous timing system an organism uses to synchronise it’s activities with the environment

Question 4

Biological rhythm

Answer 4

Physiological changes in activity in living organisms occurring in a cyclic manner. Most often associated with predictable daily, monthly, or annual environmental changes

Question 5

Circadian rhythm

Answer 5

An endogenous rhythm of rest and activity that approximates 24 hours and is entrained by the light-dark cycle

Question 6

Circalunar

Answer 6

An endogenous rhythm that approximates the lunar cycle and is entrained by it, but will continue to occur in the absence of the environmental cue

Question 7

Circatidal

Answer 7

An endogenous rhythm that approximates the tidal cycle and is entrained by it, but will continue to occur in the absence of the environmental cue

Question 8

Crepuscular

Answer 8

An organism that is active during the periods of dawn and dusk

Question 9

Diurnal

Answer 9

An organism that is active doing the period of daylight

Question 10

Endogenous

Answer 10

A stimulus originating within the organism itself, e.g. Hormonal changes, is this

Question 11

Entrainment

Answer 11

The synchronisation of and endogenous rhythm with an external cycle such as light and dark

Question 12

Environmental cue

Answer 12

Stimulus from the environment used by animals and plants to establish and maintain a pattern of activity e.g. Day length, temperature

Question 13

Exogenous

Answer 13

An environmental stimulus that is external to the organism (e.g. Day length) is referred to as this

Question 14

Free running period

Answer 14

I the period of an endogenous rhythm when given no external environmental cue by which to synchronise the rhythm

Question 15

Jet lag

Answer 15

Condition caused by the asynchrony between the endogenous circadian rhythm and the external cues, usually cause by travelling across time zones

Question 16

Long-day plant

Answer 16

Plant that flowers when exposed to dark periods of less than critical lengths

Question 17

Lunar rhythm

Answer 17

A biological rhythm synchronised to the lunar cycle, occurring monthly

Question 18

Nocturnal

Answer 18

Organism that is active mainly during the night

Question 19

Period

Answer 19

The time it takes to complete the entire cycle of an organism’s biological rhythm

Question 20

Phase shift

Answer 20

The shifting of a period of activity from one particular time to another

Question 21

Photoperiodism

Answer 21

The physiological reaction of plants and animals to the presence and absence of light

Question 22

Phytochrome

Answer 22

A pigment in plants responsible for the photoperiodism effect. Regulates the timing of flowering with different effects in long day and short day plants

Question 23

Short-day plant

Answer 23

Plants that require a period of dark exceeding a certain length

Question 24

Tidal rhythm

Answer 24

A biological rhythm synchronised to the tidal cycle, occurring about every 12.5 hours with the transition from high to low tide and back

Question 25

Zeitgeber

Answer 25

An exogenous cue that synchronises an organism’s endogenous rhythms to the rhythms of the environment, e.g. The sun or the light-dark cycle