Diversity & Variation
Why is it important for a species to have genetic diversity in a changing environment?
Greater genetic diversity increases the chances that some individuals will survive and reproduce under new conditions.
How do different finch beaks help reduce competition in the Galápagos Islands?
Each beak shape is adapted for a different food source, allowing them to occupy separate niches.
How can symbiosis increase biodiversity in an ecosystem?
By allowing different species to coexist and benefit from each other, stabilizing the ecosystem.
Why does asexual reproduction typically produce less variation in offspring than sexual reproduction?
Offspring are genetic clones of the parent in asexual reproduction.
Why might siblings with the same parents still look different?
They inherit different combinations of genes due to sexual reproduction.
Compare and contrast variation within a species and variation between species using an example.
Within a species, wolves may vary in fur color; between species, wolves and foxes have different body structures and behaviors.
If two species have the same niche, what are two possible outcomes of this overlap?
One species outcompetes the other, or one adapts to use a different niche (niche differentiation).
Why might removing a keystone mutualistic species cause an ecosystem to collapse?
Other species that depend on that mutualism may also decline or go extinct, triggering a chain reaction.
Describe how sexual reproduction contributes to evolution more effectively than asexual reproduction.
It creates more genetic combinations, increasing the likelihood of beneficial traits appearing and spreading.
Why are identical twins not genetically identical later in life?
Environmental factors (diet, lifestyle, stress) can affect gene expression, causing differences.
Explain how variation helps maintain balance in a food web.
Variation in diet or hunting behavior can reduce competition and help multiple species coexist.
Why would a highly specialized species be more vulnerable to extinction?
It depends heavily on a specific resource or condition, so if that changes, it may not survive.
Explain the difference in impact between parasitism and mutualism on biodiversity.
Mutualism can enhance survival and stability; parasitism can reduce individual fitness but may increase host diversity over time.
Compare binary fission and budding in terms of energy and speed.
Both are fast and energy-efficient, but budding involves growth from the parent’s body, while binary fission splits the cell.
Why is it important to understand inheritance when breeding animals or growing crops?
To select for desirable traits like disease resistance, growth rate, or yield.
How does natural selection act on variation within a population?
Individuals with traits better suited to the environment are more likely to survive and pass on those traits.
Describe how seasonal changes might test the niche flexibility of an animal.
Animals must adapt behaviors (e.g., migration, hibernation, diet changes) to maintain their niche through winter.
Classify and justify the relationship between clownfish and sea anemones.
Mutualism – clownfish get protection, anemones get cleaning and nutrients from fish waste.
Describe how zygote formation ensures genetic variation.
It combines DNA from two gametes, mixing traits from both parents.
A boy has attached earlobes, while both his parents have free earlobes (a dominant trait). What could explain this inheritance pattern?
Both parents are heterozygous carriers of the recessive allele for attached earlobes.
Design a hypothetical situation where low variation could lead to species extinction.
A plant population with low genetic diversity might be completely wiped out by a new fungal disease.
Explain how interspecies competition can drive evolutionary change.
Competition pressures species to adapt different behaviors or traits, leading to evolutionary divergence.
Predict the effect of introducing a non-native parasite into a stable ecosystem.
It could harm native species that lack resistance, disrupt existing symbiotic relationships, and reduce biodiversity.
Explain why organisms that reproduce both sexually and asexually have an evolutionary advantage.
They can use asexual reproduction for fast growth in stable environments and switch to sexual reproduction for variation when conditions change.
A breeder wants to create a dog that’s hypoallergenic, has a curly coat, and friendly behavior. Why is predicting these traits complex, even when selecting parent dogs that have them?
Many traits are polygenic (influenced by multiple genes) and affected by the environment, so offspring can show a wide range of combinations.