Plants & Animals
A plant growth response to touch or contact (e.g., positive thigmotropism = a climbing vine wrapping around a support).
thigmotropism
What is a circalunar rhythm?
A rhythm that follows the phases of the moon (about 29 days).
Environmental factors that favour certain traits over others.
selection pressure
This type of speciation occurs when populations are separated by a physical barrier like a mountain range.
allopatric speciation
In which stone industry did humans begin to make fish hooks?
Upper Paleolithic
What is a nastic response?
A non-directional plant movement in response to a change in stimulus (e.g., tulip opening during day and closing at night).
What is entrainment?
The process by which an organism’s biological rhythm is reset by external cues like light or temperature.
When one species evolves in response to changes in another
convergent evolution
When unrelated species develop similar traits due to similar environments, its called?
convergent evolution
What is one advantage and one disadvantage of short-term shelters?
Advantage: quick to build and move
Disadvantage: poor protection from weather.
What is hydrotropism and why is it adaptive?
Growth of plant roots toward water, helping roots locate moisture for survival.
Two harmful species resemble each other, reinforcing predator avoidance.
What is Müllerian mimicry?
When populations can’t breed because of physical differences in mating organs.
reproductive isolation
Structures with similar ancestry but different functions, like a bat’s wing and human arm.
homologous structures
What evidence is considered a biological or molecular clock for tracing evolution?
mtDNA & yDNA
What is homing and how is it different from migration?
Homing is returning to a home site; migration is large-scale movement between habitats.
What are diurnal, nocturnal, and crepuscular activity patterns?
Diurnal = active during day, Nocturnal = active at night, Crepuscular = active at dawn/dusk.
what is genetic drift
Random changes in allele frequencies due to chance events.
What is a temporal barrier?
A reproductive barrier caused by species mating at different times of the year.
What changes took place in the hands of hominids to allow a precision and power grip?
Shorter fingers, opposable thumb, and increased thumb mobility enabling tool use.
Describe how kineses can help animals survive in new environments.
by changing their rate of movement in response to environmental conditions
— moving faster in unfavourable areas and slower in favourable ones
— helping them stay in suitable habitats and avoid stress
Explain how endogenous rhythms give organisms an adaptive advantage
They allow anticipation of regular environmental changes (like daylight), improving feeding or reproductive success.
This speciation happens within the same geographic area when groups adapt to different niches.
sympatric speciation
The development of many species from one ancestor to occupy different niches.
adaptive radiation
Why was drinking milk an evolutionary advantage?
Lactase persistence meant adults could digest lactose in milk, providing a reliable source of nutrients such as calcium and energy, especially during food shortages.