Vocabulary
What is a population?
A GROUP OF THE SAME TYPE OF ORGANISM LIVING IN THE SAME AREA.
A generation is...
A GROUP OF INDIVIDUALS BORN AND LIVING AT ABOUT THE SAME TIME.
Everything surrounding an organism, living and nonliving, describes the...
ENVIRONMENT.
THE PROCESS BY WHICH THE DISTRIBUTION OF TRAITS IN A POPULATION CHANGES OVER MANY GENERATIONS.
WHEN DISTRIBUTION OF TRAITS IN A POPULATION CHANGES OVER GENERATIONS.
What do genes do?
GIVE INSTRUCTIONS FOR MAKING PROTEINS MOLECULES.
Define a trait.
A SPECIFIC CHARACTERISTIC OF AN INDIVIDUAL.
A CHARACTERISTIC OF AN INDIVIDUAL ORGANISM.
Why are adaptive traits important in a population?
THEY ALLOW SOME INDIVIDUALS TO SURVIVE IF THE ENVIRONMENT CHANGES.
THEY ALLOW SOME INDIVIDUALS TO SURVIVE.
What is an adaptive trait?
A TRAIT THAT MAKES IT MORE LIKELY THAT AN INDIVIDUAL WILL SURVIVE IN A SPECIFIC ENVIRONMENT.
What are individuals with adaptive traits more likely to do?
THEY SURVIVE LONGER AND REPRODUCE.
THEY SURVIVE LONG ENOUGH TO REPRODUCE.
What specifically determines an organism’s traits?
PROTEIN MOLECULES.
What is variation?
A DIFFERENCE IN TRAITS BETWEEN INDIVIDUALS. A DIFFERENCE IN TRAITS.
*without mutation*
Can a population can change if it has no variation? Why or why not?
NO; THERE ARE NO DIFFERENT TRAITS TO CAUSE A CHANGE.
If an organism doesn't survive long enough to reproduce, it probably has...
A NON-ADAPTIVE TRAIT.
TRUE OR FALSE
Organisms decide to change their traits because they “need” to.
FALSE; THEY CANNOT CHANGE A TRAIT JUST BECAUSE THEY WANT TO.
Through what are traits passed from parents to offspring?
GENES.
What does distribution mean?
THE NUMBER OF INDIVIDUALS WITH A SPECIFIC TRAIT IN A POPULATION.
There's a population of 50 birds.
If 20 have long beaks and 30 have short beaks, what does that describe?
DISTRIBUTION (NUMBER OF INDIVIDUALS WITH EACH TRAIT).
A population of insects becomes mostly dark-colored after living on dark tree bark for many generations. Why?
DARK COLOR IS AN ADAPTIVE TRAIT IN THAT ENVIRONMENT.
DARK COLOR BECAME AN ADAPTIVE TRAIT.
In a cold environment, animals with thick fur survive better. What happens to the traits over generations?
THICK FUR BECAME MORE COMMON.
What can suddenly introduce new traits to populations?
MUTATIONS.
Define a mutation.
A RANDOM CHANGE TO A GENE THAT SOMETIMES RESULTS IN A NEW TRIAT.
A RANDOM CHANGE TO A GENE.
Over many generations, what happens to traits that help survival?
THEY BECOME MORE COMMON.
Can the same trait be adaptive in one environment but not another?
YES.
What are the cause and effect in natural selection?
CAUSE = ENVIRONMENT.
EFFECT = CHANGE IN TRAIT DISTRIBUTION IN A POPULATION.
If a mutation gives an individual a helpful trait, what must happen for it to spread?
THE INDIVIDUAL MUST SURVIVE AND REPRODUCE.