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WorksheetsEvolutionary Genetic Variation
Total questions: 14
Worksheet time: 7mins
A population of birds lives on a small island. Another population of the same species lives on the mainland. The distance between the island and the mainland is too great for birds to fly back and forth. Recently, a series of sandbars and tiny islands have formed between the island and the mainland. What is the most likely effect of this change?
an increase in mutations in both bird populations
an increase in gene flow between the bird populations
an increase in genetic drift between the bird populations
an increase in mutations in the island population
When genetic information travels from one population to another it is called _____.
variation
gene flow
bottleneck effect
genetic drift
Which of the following examples can cause gene flow between populations?
an increase in predators to a population of zebra
a volcanic eruption that kills half of a population of mice
bird droppings that contain seeds from a different location
a person that sprays a toxin on a group of mosquitoes
The sum of all of the genetic traits in a population's individuals at any given time is known as the _____.
gene pool
genetic drift
bottleneck effect
founder effect
Henry was studying two populations of the same species of lizards. One population lived on an island and the other lived on the mainland. Both populations were affected by a hurricane that hit the island and the mainland with equal force. A year later, Henry was testing the gene frequency and saw a decrease in genetic variation in the island species, but not in the mainland species. Which best describes a conclusion he might have reached?
Gene flow greatly affects small populations, but large populations can recover.
Genetic drift greatly affects small populations, but large populations can recover.
Gene flow greatly affects large populations, but small populations can recover.
Genetic drift greatly affects large populations, but small populations can recover.
Environmental factors can influence natural selection because they can increase or decrease _____.
the number of chromosomes in an individual.
the number of chromosomes in a population.
the amount of genetic variation in an individual.
the amount of genetic variation in a population.
Which of the following can cause gene variations to INCREASE in a population?
predator-prey relationships
competition
toxins
disasters
Which of the following can cause gene variations to INCREASE in a population?
predator-prey relationships
competition
disasters
new habitat
Which environmental factor would likely lead to an increase in genetic variation in a population of squirrels?
an increase in predators
an increase in available food
an increase in forest fires
an increase in pollution
A population of snakes that eat small rodents enters a new habitat. In the new habitat, there are many species of rodents, and their populations are high because there are few natural predators. What will most likely be the effect on the genetic variation of the snake population?
Genetic variation will increase because of a selective pressure.
Genetic variation will increase because of a new habitat and food source.
Genetic variation will decrease because of a selective pressure.
Genetic variation will decrease because of a new habitat and food source.
Genetic drift in a population affects the gene pool in which of the following ways?
decreased in gene flow
increased in mutations
increase in genetic variation
decrease in genetic variation
Most gene mutations are _____.
beneficial; they improve an organism's fitness for its environment.
neutral; they do not affect an organism's fitness for its environment.
unfavorable; they tend to make organisms less fit for their environment.
none of these.
Northern Elephant Seal populations were hunted during the 1800's from a population of over a million down to just 18 individuals by 1882. The current population of Northern Elephant seals is about 175,000. As a result of this near extinction, Northern Elephant Seals have extremely low genetic diversity. What is it called when a species goes from a large population to an extremely small group of individuals which repopulate?
The Bottleneck Effect
The Founder Effect
Genetic Drift
Gene Flow
Which of these statements about the founder effect is true?
It happens when a large population is reduced down to only a few individuals.
It increases the amount of genetic diversity in a population.
It occurs when a few individuals colonize a new habitat making a new population.
The new population always has the same genetic diversity as the original population.
