1.6 Sea urchin population change check in

Which species is known to consume sea urchins in marine ecosystems?

• Dolphins

• Sea otters

• Sharks

• Turtles

What are the two main phenotypic variations observed in the sea urchin population?

• Size and shape

• Color and size

• Color and texture

• Shape and texture

How do you calculate the average diameter of sea urchins in a population?

• Add all diameters and divide by the number of urchins

• Multiply all diameters and divide by the number of urchins

• Subtract the smallest diameter from the largest

• Add all diameters and multiply by the number of urchins

Which phenotypic variation do you think sea otters select when preying on sea urchins?

(a)  

What is the expected result of the urchin lab in terms of urchin diameter due to selective pressure?

• The diameter should increase

• The diameter should decrease

• The color percentages should increase

• The color percentages should decrease

Why would the diameter of sea urchins decrease over time in the presence of sea otters?

• Smaller urchins are less visible to predators

• Smaller urchins are more nutritious

• Larger urchins reproduce less

• Larger urchins are more likely to be preyed upon

Define genetic drift

• Genetic drift is the process of gene flow between different populations.
• Genetic drift refers to the gradual change in species over time due to environmental factors.
• Genetic drift is the intentional selection of specific traits in a population.
• Genetic drift is the random fluctuation of allele frequencies in a population due to chance.

How does natural selection effect the urchin population being preyed upon by sea otters?

• Natural selection leads to urchins decreasing in size over time, making them less valuable.

• Natural selection causes the urchin population to grow larger and slower, making them more vulnerable.
• Natural selection decreases the urchin population by making them easier to catch.
• Natural selection has no impact on the urchin population's ability to survive against sea otters.

Why do sea otters select larger urchins to prey upon?

• Larger urchins are more abundant in their habitat.
• Sea otters select larger urchins for higher energy and nutrient content.
• Sea otters prefer smaller urchins for easier handling.
• They don't, they select the urchins that are most visible in the enironment- such as ones with a brighter color.

What is natural selection?

• Natural selection is the process by which organisms that are better adapted to their environment tend to survive and reproduce.
• Natural selection is the phenomenon where only the strongest individuals survive regardless of their environment.
• Natural selection is the method by which all organisms are equally likely to survive.
• Natural selection is the process of random genetic mutations.