Behaviors
Energy Flow
Population Ecology
Community Ecology
Community Ecology and Disruptions to Ecosystems
100
True or False: In the phrase “nature vs. nurture” the “nature” component refers to environmental factors that influence behavior and the “nurture” component refers to genetic factors that influence behavior.
False!
100
The transfer of energy between trophic levels is around _____ efficiency
10%
100
Which type of survivorship curve is represented by the graph below?
Type III
100
Draw and label the three dispersion patterns.
100
Identify one reason why invasive species are harmful to ecosystems.
They competitively exclude other species
They cause harm to the environment.
They grow and reproduce quickly.
200
Baby turtles move towards the brightest direction after hatching and leave their nest to head to the ocean. They have to move fast because predators are nearby. But how do they know where to go if they’ve never seen or been to the ocean?
Turtles use environmental cues, such as the light, to help them find their way; however, this behavior is innate or instinctive and does not require learning.
200
True or False: An ecosystem requires a continuous input of energy to sustain itself. Or, in other words, energy cannot be recycled in ecosystems.
True!
200
What happens to the population growth rate as it nears its carrying capacity and why?
The growth rate decreases as resource competition increases.
200
In a scenario surge in algae provides food for small protozoans like plankton, causing their populations to increase. These plankton are then eaten by small crustaceans such as crayfish, which are in turn preyed upon by larger fish like catfish or carp. Which statement best describes the role of the crayfish in this ecosystem?
They are secondary consumers.
200
After a period of deforestation by humans, the forest was able to re-grow over many years due to the soil that was already present. Which type of succession represents the regrowth of this forest and why?
Secondary Succession, because there was soil present which allowed the forest to re-grow.
300
Which type of behavior is described below?
In meerkat groups, one individual will often act as a sentry, standing upright on its hind legs to watch for predators while the rest of the group forages for food. If the sentry spots danger, it gives an alarm call to warn the group, even though this may draw attention to itself and increase its own risk of being attacked.
Altruism/Altruistic behavior
300
In a grassland ecosystem, grasses produce approximately 10,000 kilocalories of energy through photosynthesis. A herd of deer feeds on these grasses, and a pack of wolves preys on the deer. Only about 1,000 kilocalories are available to the deer from the grasses they consume, and only about 100 kilocalories are available to the wolves from the deer. What happens to the remaining energy that is not transferred from one trophic level to the next?
Energy is "lost" (aka released) in the form of heat due to metabolic processes in the deer and wolves. Metabolic processes such as photosynthesis and cellular respiration.
300
Sturgeon fish produce millions of eggs that are fertilized and left in the river to hatch on their own. Only 10% survive. However, you can find some sturgeon fish that are 80 years old. Sturgeon exhibit what type of survivorship?
Type III - b/c they have many offspring, little parental care, high early mortality, and long lifespan for those few that survive.
300
(1) What is a community?
(2) What could you remove from a community to have the most negative impact?
(1) A community is a group of populations of different species living closely and capable of interacting with each other.
(2) Keystone species
300
Which specific type of interaction is this and why?
Because two rabbits (who are the same species) competing/fighting, this is intraspecific competition.
400
Using what you know about animal behavior, explain what is happening in the series of photos regarding ants and why it benefits the colony.
Ants can recognize trail pheromones from other ants and use this trail to find resources, which increases overall colony survival.
400
A researcher finds that during winter the primary productivity of a deciduous forest ecosystem is lower due to less sunlight. As a result, there is a noticeable decline in the herbivore population, which then impacts the higher trophic levels. What does this finding illustrate about the energy flow in ecosystems?
Energy flow is dependent on primary producers and varies seasonally. When there's less sunlight in winter, photosynthesis productivity decreases, meaning less energy is available at the base of the food chain. This reduction affects herbivores, which depend on plants for food, and then impacts higher trophic levels, such as predators.
400
In a freshwater lake, the population of a certain fish species has been declining. Scientists observe the water temperature has increased steadily over the past decade due to climate change, human pollution from nearby agriculture has caused periodic algal blooms, reducing oxygen levels in the water, and increased fishing activity has reduced the adult fish population significantly.
(1) Identify a density dependent and independent factor from the example.
(2) Label which factors are biotic and abiotic.
Density Dependent Factor - human pollution and increased fishing activity (Biotic)
Density Independent Factor - water temperature increasing (Abiotic)
400
Some plants, like sage, release toxins into the soil, which prevents other plants from growing in close proximity. Knowing this, what kind of dispersion pattern might you expect to see in a population of sage plants?
Uniform – b/c if sage plants release toxins to prevent other plants from growing nearby, they can spread out more uniformly without competition.
400
What term best describes an excessive amount of nutrients in an ecosystem, and what types of harm can this cause?
Eutrophication
Eutrophication can be harmful because it causes an imbalance of nutrients in the ecosystem, leading to damaged habitats and reduce biodiversity.