Vocabulary
In a bird population, scientists observe that some birds have grey feathers, some have white feathers, and others have brown feathers. These differences in feather color are an example of:
Variation
_________ contain instructions that cells use to build protein molecules that help determine traits.
Genes
In a habitat with many predators, organisms that blend into their surroundings survive more often because of:
Camouflage
True or False: Natural selection causes individuals to develop helpful traits during their lifetime.
False
Scientists create a graph showing how many organisms have low, medium, or high toxin levels. This graph is called a:
Histogram
In a population of rabbits, some rabbits have longer ears while others have shorter ears. Ear length (short, medium, long) is an example of a:
Trait
A random change occurs in the DNA of an organism, creating a new version of a trait. This change is called a:
Mutation
Predators, food availability, disease, and climate are all examples of:
Environmental pressures
In a moth population living in an area where volcanic ash has darkened tree bark, scientists track changes in body color and observe a shift in the most common color. This type of population change happens across what timeline?
Many generations
A histogram shows that most organisms in a population have low toxin levels, with very few having high levels. This shows the population’s trait:
Distribution
In a forest environment, brightly colored insects are easily seen and eaten by predators. Bright coloration is considered a(n):
Non-Adaptive Trait
True or False: Mutations occur because organisms need to adapt to their environment.
False
A disease wipes out nearly all organisms in a population because every individual has the same weakness. This population likely had:
No variation
A population of wolves has variation in hunting success. Wolves that are slightly faster catch more prey and are more likely to reproduce. Over generations, the population shifts toward:
Higher speed
A histogram with bars spread evenly across many trait values suggests the population has ________ genetic variation.
High
In a snowy environment, white fur helps rabbits avoid predators more successfully than brown fur. White fur is considered a(n):
Adaptive Trait
In a population of insects, a random change in DNA produces a new protein that slightly improves camouflage. This change is called _____________ mutation.
Beneficial
After a major environmental change, a population with many different traits is more likely to survive because it has:
High variation
A population of birds becomes better camouflaged over many generations because birds with helpful traits survive and reproduce more. This population change is called:
Adaptation
A histogram with almost all organisms clustered around one trait value suggests ________ genetic variation.
Low
Scientists compare how common different toxin levels are within a newt population. The pattern they observe is the population’s:
Distribution
A mutation changes the structure of a protein so that it no longer functions properly in breaking down toxins. This would most likely affect the organism’s:
Ability to survive
In a population of rough-skinned newts, scientists observe that toxin levels increase over many generations. What factor is most likely responsible for this change in the population?
Predation (snakes)
A population of bacteria becomes resistant to antibiotics after many generations because resistant bacteria _____________ and _____________.
Survive; reproduce
Over time, a histogram shifts so that more organisms show higher toxin levels than before. This indicates a change in:
Traits