Adaptations 🐾 Flashcards
What are adaptations?
Characteristics that increase organism’s chance of survival + reproduction in its environment.
Define anatomical adaptations:
physical features (internal/external)
Define behavioural adaptations:
way an organism acts.
Inherited/learnt from parent
Define physiological adaptations:
Process that take place inside an organism.
Examples of anatomical adaptations:
Body covering –> hair, scales, feathers, thick waxy layer on plants.
Camouflage –> outer colour of animal to blend in environment.
Teeth –> shape/type of teeth related to diet.
Mimicry –> copy other animals appearance/sound to fool predators
What adaptations do marram grass have?
xerophyte
curled leaves minimise SA of tissue exposed to air –> protect leaf from wind.
Hairs on inside surface of leaf –> trap moist air close to leaf - reduce diffusion gradient.
Sunken stomata –> less likely to lose water
Thick waxy cuticle –> reduce water loss through evaporation
Examples of behavioural adaptations:
Survival behaviours –> opossum play dead when they’ve been seen
Courtship –> to attract a mate. Increases chance of reproducing
Seasonal behaviours:
~>migration: movement from one region then back again when environmental conditions more favourable.
~>hibernation: period of inactivity when animal’s body temp, heart rate + breathing rate slows to conserve energy
What are the two main categories behavioural adaptations fall into:
Innate (instinctive) behaviours
–> ability to do this inherited through gene (spider making web)
Learned behaviour –> adaptations learnt from experience/observing other animals (sea otters use stones to hammer shells off rocks)
Examples of physiological adaptations:
Poison production –> reptiles produce venom to kill prey
Antibiotic production –> some bacteria produce antibiotics to kill other specie of bacteria
Water holding–> camels + cacti
Temperature regulation
High number of certain organelles (sperm cells)
What is convergent evolution?
When unrelated species begin to share similar traits
Due to organism adapt to similar environments/selection pressures. —> live in similar way to each other
How do anatomical adaptations provide evidence for convergent evolution?
Analogous structures
–> structure have adapted to perform same function but have different genetic origin.
e.g: whale fin + dolphin fin = same function but structurally look very different.
–> marsupial + placental mice
Define selection pressures:
Factors that affect that organism’s chance of survival or reproductive success.
What are the steps of natural selection?
New allele arises by mutation
Best adapted organisms to selection pressure (predation, competition)
~~>Less well-adapted organisms die to fail to reproduce. ‘survival of fittest’
Successful organisms pass allele encoding the advantageous characteristics onto their offspring
Repeated for every generation.
Over time advantageous adaptation increases.
.: frequency of allele that codes for characteristics increase in population gene pool.
Many, many generations –> evolution of new species
Example of evolution:
MRSA developed resistance to many antibiotics.
Bacteria divide very rapidly –> DNA altered due to resistance
.:Number of resistant bacteria increase in shorter period of time.
Example of evolution:
Peppered moths.
Change due to selection pressure making dark coloured moths = more advantageous allele.
