Question

1. which statement about food chains is correct?

• a. energy flows from consumers to producers
• b. they show only predator - prey relationships
• c. energy is transferred from one organism to another
• d. they include all species in an ecosystem

1. what happens when a population exceeds its carrying capacity?

• a. the birth rate increases
• b. the population immediately stabilizes
• c. the death rate typically increases
• d. resources become more abundant

1. how is birth rate typically expressed?

• a. total number of offspring per year
• b. number of offspring per female per lifetime
• c. number of births per 1,000 individuals per year
• d. percentage of pregnant females in a population

1. what typically happens at the end of a food chain?

• a. energy is recycled back to producers
• b. energy is completely conserved
• c. energy is lost as heat
• d. energy increases

1. what is the relationship between birth rate and carrying capacity?

• a. they are always directly proportional
• b. birth rate often decreases as carrying capacity is approached
• c. they have no relationship
• d. birth rate increases with carrying capacity

1. what determines the length of a food chain?

• a. the size of the largest predator
• b. available energy at each trophic level
• c. number of herbivores
• d. ecosystem age

Explanation:

• Question 25: In a food - chain, energy is transferred from one organism to another as one organism consumes another. Energy flows from producers to consumers. Food - chains don't show all species in an ecosystem and are not just about predator - prey relationships.
• Question 26: When a population exceeds its carrying capacity, resources become scarce, leading to an increase in the death rate as individuals struggle to survive.
• Question 27: Birth rate is commonly expressed as the number of births per 1,000 individuals per year.
• Question 28: At the end of a food - chain, energy is lost as heat during metabolic processes and is not recycled back to producers or conserved completely.
• Question 29: As the carrying capacity of an environment is approached, the birth rate often decreases due to limited resources and increased competition.
• Question 30: The length of a food - chain is determined by the available energy at each trophic level. Energy is lost at each transfer, so there is a limit to how long a food - chain can be.

Answer:

• 25. c. Energy is transferred from one organism to another
• 26. c. The death rate typically increases
• 27. c. Number of births per 1,000 individuals per year
• 28. c. Energy is lost as heat
• 29. b. Birth rate often decreases as carrying capacity is approached
• 30. b. Available energy at each trophic level