Yr 10 Science - Biology Flashcards
What is evolution?
Evolution is a process of descent with modification. It is the gradual change of a species characteristics over the course of several generations. It happens when genes mutate and cause new characteristics that are passed down.
What is the purpose of evolution?
Evolution enables an organism to adapt to its environment and help them to survive. The traits they gain through evolution are passed down genetically.
What are the five basic steps of natural selection?
VISTA -
1. Variation, the gene pool allows for some variation within a species.
2. Inheritance, the traits encoded in DNA are passed on to offspring.
3. Selection, not all organisms that are born can survive. Organisms that have variations that better suit their environment are more likely to survive.
4. Time, organisms with better variables and traits are more likley to survive and reproduce. These traits are passed on to greater and greater numbers of offspring.
5. Adaption, the result is a population that is better suited–better adapted–to some aspect of the environment than it was before.
Why does each species look different?
Each species has evolved to suit their environment. This means all species have different DNA that suits their living conditions.
Why does no organism look the same, despite being the same species?
Every organism has slightly different genes and chromosomes that they have inherited from their parents. While they are largely the same as other organisms within their species, more specific traits are different.
What are adaptions?
Adaptions are features that promote the survival and reproduction of an organism. Allowing a species to be better suited to it’s environment. It is a product of natural selection.
What are the mechanisms that cause organisms to experience evolution?
Natural selection, mutation, genetic drift, gene flow, selective breeding,
What are the three types of adaptation?
Structural/physical, behavioural, functional/physiological
What is a functional/physiological adaptation?
Features resulting from metabolic or biological processes the organism’s body performs that improves chance of survival and reproduction. These processes are internal systems that affect an organism’s physiology or biochemistry.
What is a structural/physical adaptation?
Physical features of an organism that improve its change of survival and reproduction.
What is a behavioural adaptation?
Actions or activities of an organism that improves its chance at survival and reproduction. These are actions that the organism can control
What are some examples of a behavioural adaption?
Burrowing, nocturnality, hibernation, mating tactics, migrating, climbing.
What are some examples of a structural/physical adaptation?
Camel’s humps, giraffe’s long neck, cacti thorns, fish’s gills, snake’s flexible jaw, frog’s strong legs.
What are some examples of a functional/physiological adaptation?
Poisons secreted by frogs/snakes/scorpions, changing body temperature, camouflage, releasing smelly gas, venom.
What type of adaptation is the beak of a bird?
A structural/physical adaptation.
What type of adaptation is a camel storing and breaking down fat in it’s humps?
A functional/physiological adaptation.
What type of adaptation is a turtle returning to the beach they were born on to lay their eggs?
A behavioural adaptation.
What happens to species unable to adapt?
They die off and eventually become extinct.
What are embryological similarities?
Embryo’s of diiferent animals can show similarities. For example, fish embryos and human embryos both have gill slits.
What are vestigial structures?
A feature passed down from ancestor that no longer has a purpose in the current form of the organism.
What are homologous structures?
Features in different organisms that appear similar, due to their shared ancestry, but have different purposes.
What is selective pressure?
A selective pressure is any reason for organisms with certain traits to have either a survival benefit or disadvantage. Selection pressures are external agents which affect an organism’s ability to survive in a given environment. E.g. predation, competition and disease.
What should be the outcome of natural selection?
A species gradually becomes better suited to its environment
What is geographic isolation?
When two populations of the same species are divided by some type of geographic event or object. When one group is stuck in a new environment.
