Plant and Animal Responses in Time

Level 3 Biology Study!

_______ rhythms are internally driven

endogenous

endogenous rhythms are controlled by a/an _______ _______ when the _______ of the activity continues in _______ _______ _______, in the _______ of environmental _______

internal clock, rhythm, constant environmental conditions, absence, cues

an internal clock is set/adjusted, or “_______” by environmental _______ known as “_______”

entrained, cues, zeitgebers

_______ rhythms are solely externally driven

exogenous

do endogenous or exogenous rhythms continue in constant conditions?

endogenous

the _______ is the length of a cycle of a rhythm, between successive onsets of an activity

period

a rhythm becomes _______ when in constant environmental condition

free-running

a rhythm following its _______ _______ may drift slightly out of sync with external periods (eg, sunset) if in _______ conditions

free-running period, constant

for an internal clock to be _______, a _______ must be detected by a _______

entrained, zeitgeber, receptor

for entrainment of the waking/sleeping circadian cycle:

1. _______ are the _______ which pick up light

2. message transmitted to the ___ in the _______, which is transmitted to the _______ gland

3. _______ hormone is secreted when there is no light

eyes, receptors, SCN, hypothalamus, pineal, melatonin

a _______ _______ may occur if an internal clock is entrained by a zeitgeber in a lab

phase shift

a rhythm - often circadian or tidal - can be represented using a/an _______

actogram

an actogram is a _______ indicating the organism’s _______ of activity

graph, periods

in an actogram, the _______ is removed, allowing the _______ rhythm to follow its _______ _______ which is often shorter or longer than 24h

zeitgeber, endogenous, free-running period

_______ _______ is unique to each organism, and determined by its genetic makeup

free-running period

to determine FRP from an actogram:

1. calculate the _______ (h) forwards/back in the onset of the activity

2. divide this value by the number of _______ over which this was calculated

3. add or subtract this _______ _______ from 24h, or the length of a normal cycle, to determine FRP

shift, periods, phase shift

daily rhythms are ___ h, and due to the _______ _______ about its _______

24, Earth, rotating, axis

_______ rhythms are where an organism is active during the day

diurnal

_______ rhythms are where an organism is active during the night

nocturnal

_______ rhythms are where an organism is active during sunrise and sunset

crepuscular

daily rhythms are affected by _______ changes in _______

seasonal, photoperiod

annual rhythms are ____ days are due to the Earth _______ the _______

orbiting, Sun

seasons are created due to the _______ of the Earth as it _______ and _______ the Sun

tilt, rotates, orbits

_______ is an adaptation allowing animals to survive winters with low _______ supplies, requiring accumulation of _______ deposits and a lowered _______ rate

hibernation, food, fat, metabolic

_______ is a seasonal/annual rhythm allowing animals to survive hot, dry periods (summer) with limited _______ availability, involving a reduced _______ rate and a retreat to a microhabitat

aestivation, water, metabolic

breeding patterns are often seasonal/annual, to maximise available _______ (eg, food, nesting sites), optimise t_______ and p_______, and to _______ with others in their species

resources, temperature, photoperiod, sync

_______ growth is a seasonal/annual pattern, which is important to _______ before the onset of cold or hot weather

coat, anticipate

_______ is an adaptation allowing _______ to survive unfavourable environmental conditions, involving a programmed halt in _______ and a lowered _______ rate until conditions improve

diapause, insects, development, metabolic

tidal rhythms occur every ___h with around __ every 24h, and are due to the _______ pull of the _______ on the _______ as the Earth _______

12.4, 2, gravitational, sea, rotates

to form tides, does water pile up towards and away from the Moon, or on each side of the Earth from the Moon?

towards and away from

low tide is on _______ (each side of Earth / towards and away from the Moon)

each side of Earth

lunar rhythms are ___ days due to the _______ of the _______ around the _______

28, rotation, Moon, Earth

before salmon migrate downstream to estuaries, the new moon stimulates the release of _______ hormone to bring about _______ changes to regulate internal _______ concentrations in sea water; an example of a/an _______ rhythm

thyroxine, physiological, salt, lunar

_______ inhabitants alternatively live on land (activity _______ (increases / decreases)) and live underwater (activity _______ (increases / decreases)), and follow _______ rhythms to optimise feeding and reproduction

intertidal, decreases, increases, tidal

_______ movements are “sleeping” movements of plants as they open and close, most likely to be in sync with _______ animals

nyctinastic, pollinator

_______- means about, and applies to endogenous rhythms in constant conditions, following their FRP

circa

_______ rhythms are influences by more than 1 environmental factor

compound

annual rhythms in plants are due to changes in _______, and include _______ fall in _______ plants, flower/bud/bulb formation, and seed _______

photoperiod, leaf, deciduous, germination

photoperiodism is detected by _______ in plants

phytochrome

phytochrome is in the _______ cells of plants

leaf

phytochrome is a _______ coloured _______

blue, protein

phytochrome has __ interchangeable forms

2

Pr absorbs _______ light and is the _______ form

red, inactive

_______ light is 665nm; _______ light is 725nm

red, far-red

PFr absorbs _______ light and is the _______ form

far-red, active

when Pr absorbs _______ light, in the highest concentration over the _______, it _______ converts to PFr

red, day, quickly

when PFr absorbs _______ light, which must be artificially produced, it _______ converts to Pr

far-red, quickly

in the _______ of light, at _______, ___ _______ converts into ___

absence, night, PFr, slowly, Pr

white light during the day has a higher concentration of _______ light

red

long day plants, LDP, require high concentrations of ___ to produce _______ _______

PFr, flowering hormone

short day plants, SDP, require high concentrations of ___ to produce _______ _______

Pr, flowering hormone

LDP’s flower when the day length _______ (exceeds / is less than) the CDL

exceeds

SDP’s flower when the day length _______ (exceeds / is less than) the CDL

is less than

CDL stands for _______ _______ _______

critical day length

day-_______ plants, DNP’s, flower _______ of photoperiod

neutral, independently

plants without _______, and therefore without _______, are _______ plants

leaves, phytochrome, day-neutral

do plants flower due to concentration of PFr, or due to flowering hormone?

flowering hormone

interruption by _______ or _______ light increases ___ concentration and causes LDP’s to flower

red, white, PFr

interruption by _______ light increases ___ concentration and causes SDP’s to flower

far-red, Pr

_______ is promoting flowers to _______ to induce _______; flowers in _______ climates require long _______ periods in addition to _______ cues before flowering

vernalisation, chilling, flowering, temperate, cold, photoperiod

photoperiod responses allow plants and animals to anticipate and prepare for _______ changes

environmental

plants use photoperiodism to:

• produce _______ when _______ are active, increasing chances of c_______ followed by f_______

• expend energy and resources only when longer _______ hours/intensity allows for more _______, to optimise times for _______ and _______ production

flowers, pollinators, cross-pollination, fertilisation, light, photosynthesis, growth, seed