Natural Selection
All living things share a ____________.
Common ancestor
Both natural selection and genetic drift are mechanisms or drivers of __________.
Evolution
Nucleus
Give three examples of environmental pressures.
Shortage of food and water, space / shelter, predators
Does genetic drift have a stronger effect on larger populations or smaller populations?
Smaller populations
Random differences exist between siblings because each parent passes on a random ___% of their DNA.
50%
What does it mean for one organism to be more "fit" than another in "survival of the fittest"?
Better adapted to their environment / can survive better
Genetic drift is a change in the frequency of ________ in a population because of random events.
Alleles
Name the two main types of traits. Circle the type that plays a role in natural selection.
Environmental traits and inherited traits.
Natural selection happens when:
A) Organisms born with traits that help them survive pass those traits on to offspring
B) Organisms that are worse at adapting to their environment die out
C) A random event kills off many organisms with the same trait
D) Both A and B
D) Both A and B
There are two types of fish living in a river. Most of them have small fins, but a few have big fins. Humans start to dump toxic garbage into the river. This kills many fish, including most of the fish with big fins. What type of genetic drift effect has happened?
Bottleneck effect
An allele is a _______ of a gene.
Form / variant / variation / version
What is Darwin's equation for natural selection?
Variation + Pressure = Change Over Time
Imagine a field with flowers of many different colors. An owl eats some flower seeds, flies to a new island, and spits the seeds in a pellet. By chance, all the seeds are from pink flowers and they all germinate. Years later, the island is full of pink flowers. What type of genetic drift effect has happened?
Founder's Effect
It is impossible for two parents who have a dominant trait (e.g. can taste PTC) to have an offspring with a recessive trait (cannot taste PTC). True or false?
False