Adaptation and Variation Flashcards
(28 cards)
What are the three main types of adaptations in animals?
Physiological: Changes in body processes (e.g. snakes producing venom)
Anatomical: Structural changes in the body (e.g. bats’ forelimbs forming wings)
Behavioural: Changes in activity or habits (e.g. bord migration to avoid cold climates)
Define physiological adaptation with an example
Physiological adaptation involves internal body functions that help survival
Example: A snake’s ability to produce venom for capturing prey or self-defense
Define anatomical adaptation with an example
Anatomical adaptations involve physical body features that aid survival
Example: The forelimbs of bats evolving into wings for flying and accessing food
Define behavioural adaptation with an example
Behavioural adaptations are learned or instinctive actions that help an animal survive
Example: Birds migrating to warmer areas to avoid harsh winters
How do diet, lifestyle, and environment influence adaptations?
Diet: Predators may evolve sharper teeth or digestive traits
Lifestyle: Nocturnal animals may develop enhanced night vision
Environment: Camouflage or hibernation may develop based on climate and terrain
Give one animal example for each of these adaptation causes: Diet, Lifestyle and Environment
Diet: Ruminants like cows have adapted stomachs for digesting tough plant matter
Lifestyle: Moles are adapted to a burrowing lifestyle with large claws
Environment: Artic foxes have thick fur and white colouring to blend with snow
Describe the adaptations of a polar bear
Large, fur-covered feet for icy grip
Small ears and large body to conserve heat
Thick white fur for insulation and camouflage
Sharp claws and teeth for hunting
Strong legs for swimming and chasing prey
Thick adipose tissue for insulation and energy reserves
Pregnant females hibernate
Keen sense of smell and hearing for locating prey
What is the definition of ‘evolution’?
Evolution is the gradual change in the inherited characteristics of a species over successive generations, often leading to the development of new species
What is ‘speciation’?
Speciation is the process through which populations evolve to become separate species due to accumulated genetic and behavioural differences
Define the term ‘genotype’
A genotype refers to the complete set of genes inherited from an organism’s parents. It determines potential traits
Define the term ‘phenotype’
Phenotype is the observable characteristics of an organism, resulting from the interaction of its genotype with the environment
What is variation in biological terms?
Variation is the genetic and physical differences between individuals of the same species. These differences may be heritable and contribute to survival
Why is variation important in natural selection?
Some variations provide survival advantages, allowing individuals to live longer, reproduce more, and pass on beneficial traits
Explain the process of natural selection
Natural selection is where organisms with traits better suited to their environment survive, reproduce, and pass on these traits. Over time, the population evolves to favour those traits
Describe the beetle example of natural selection
In an environment with brown backgrounds, green beetles are more visible to predators, while brown beetles survive longer and reproduce. Over time, brown beetles become dominant
How does natural selection lead to evolution?
Beneficial traits become more common in the population, and harmful traits diminish. Over many generations, this accumulation of traits results in evolutionary change
How does natural selection lead to speciation?
If different variations in isolated populations provide different survival advantages, over time they may become so different they can no longer interbreed - thus forming new species
What is a stabilising selection pressure?
It reduces variation by selecting against extreme traits and favouring the average phenotype
Example: Warning colouration that helps animals avoid predators
What is directional selection pressure?
It favours one extreme phenotype, often due to environmental changes
example: the rise of dark-coloured moths during industrial pollution
What is diversifying (disruptive) selection pressure?
If favours extreme phenotypes over the average, increasing variation
Example: Darwin’s finches evolving different beak shapes to exploit varied food sources
Define ‘survival of the fittest’
It means individuals best adapted to their environment are more likely to survive and pass on their genes, leading to evolutionary success
What role does the environment play in selection pressures?
Environmental changes can make certain traits more or less advantageous, guiding which phenotypes are selected for or against in a population
What are the five vertebrate classes?
Fish (Pisces), Reptiles (Reptilia), Amphibians (Amphibia), Birds (Aves), Mammals (Mammalia)
What are the characteristics of Pisces (fish)?
Breathe through gills
Wet, scaly skin
Use fins for movement
Ectothermic (cold-blooded)
Lay eggs
