Investigation 1
Investigation 2
Investigation 3
100
Give an example of a time when you were a secondary consumer in a food chain.
Any time you eat meat like chicken or beef you are a secondary consumer. Chickens and cows are both primary consumers because they eat plants like corn.
100
What are two ways that new members can be added to a population?
New members can be added to a population when babies are born, or through migration when individuals leave one population and join another.
100
What is one way that pollution affects sea otters?
1) Oil pollution can kill sea otters. If a sea otter's fur becomes coasted with oil spilled int he water, its coat can no longer trap enough air to keep it warm, and it soon dies from exposure to the cold ocean water. 2) Pollution can also weaken a sea otter's immune system, making it more susceptible to diseases that it might otherwise have been able to fight off. 3) PCB contamination in the water can cause damage to sea otters' reproductive systems, causing the population to have a lower birth rate than normal.
200
Draw and label an example of a food chain that includes a producer, primary consumer, and secondary consumer.
One example would be to show kelp (producer), sea urchin (primary consumer), and sea otter (secondary consumer).
200
How does a population grow?
When the birth rate is greater than the death rate, a population will grow.
200
Why did the deaths of sub-adult sea otters affect the growth of the whole population?
The deaths of the sub-adult sea otters cause a decline in the entire sea otter population because not only are the sub-adults removed from the population, but also they never grow old enough to reproduce and add new members to the population. Because fewer pups are born int he following years the population as a whole gets smaller.
300
What is an ecosystem? Give at least three examples.
An ecosystem is a community of living things interacting with each other and with their physical environment. There are many examples of ecosystems including kelp forest, tide pool, coral reef, rainforest, desert, pond, and garden.
300
Imagine there is a group of 149 sea otters with a birth rate of 27 percent. Use the information below to calculate the death rate for the group. Total Population = 149 Number of Deaths = 50 Based on your calculations, will the population grow or decline over time?
The population will decline because the birth rate = 27% and the death rate = 34%. If the death rate is greater than the birth rate, the population will decrease over time.
300
Name two ways that humans compete with other species.
1. Humans compete with other species for food. For example, we catch and eat many of the same foods that sea otters eat, such as clams, mussels, abalones, and sea urchins. 2. Humans also compete with other species for space. When we build new housing developments, we’re building on land that used to be home to many other species.
400
What might happen to a population of prey animals if all of its predators are taken away?
If a prey species has no predators, there would be nothing to stop its population from growing quickly. If the population became very large, there would be less food available and other species might begin to die off.
400
Imagine there is a group of 75 sea otters with a birth rate of 20 percent. Use the information below to calculate the death rate for the group. Total Population = 75 Number of Deaths = 7 Based on your calculations, will the population grow or decline over time?
Increase because the the birth rate was 20% and the death rate was approximately 9%. If birth rate is more than death rate, the population will increase.
400
What are limiting factors? Give at least three examples.
One limiting factor for animal populations is the amount of food available. A population will stop growing when there is no longer enough food within the ecosystem to support its numbers. Other limiting factors are weather, the amount of space, sunlight, water available, and the number of predators in the area.
500
How does the sea otter's niche make it a keystone species in the kelp forest ecosystem?
A keystone species is one that helps the whole ecosystem to survive. For example, sea otters are a keystone species in the kelp forest because they eat sea urchins (that is their niche). If the sea otters weren’t there, the sea urchins would eat up the kelp forest, and then the other animals would have no food and no place to live.
500
What is adaptation? Give two examples of adaptations that sea otters have.
An adaptation is a physical or behavioral trait that helps a species to survive in its natural habitat. One adaptation that has helped sea otters to survive is their webbed back feet. These help the sea otter dive in deep ocean water to find food. Another adaptation that helps sea otters survive is their very thick fur. This helps keep them warm in the water. One behavioral adaptation that helps sea otters survive is their ability to use tools. Sea otters use rocks to crack open the hard shells of clams, mussels, abalones, and other shellfish, so that they can eat the meat inside.
500
Why is it important for humans to monitor the survival of endangered species?
It is important for humans to monitor the survival of endangered species like the sea otter because many of our actions have caused these species to become endangered. When species become endangered and extinct, it can disrupt food webs and ecosystems, sometimes in ways that we could never predict. Also, endangered species are clues that the ecosystem is out of balance and could be unhealthy for many living things, including ourselves. By studying the ecosystem, we can possibly figure out how to change what we are doing to avoid hurting other species.
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