Levels of Biological Organization
What is the basic unit of life?
The cell.
What do we call organisms that make their own food, such as green plants?
Producers.
What is the main source of energy for most ecosystems?
The Sun.
Which ecological pyramid shows the amount of energy available at each trophic level?
Pyramid of energy.
A rabbit eats grass. Is the rabbit a producer or a consumer?
A consumer.
What is a group of similar cells working together called?
A tissue.
What is an organism that eats plants called?
A herbivore or primary consumer.
What process allows plants to convert light energy into chemical energy?
Photosynthesis.
What does a pyramid of biomass represent?
The total mass of living biological material at each trophic level.
What may happen to the prey population if the number of snakes in an ecosystem decreases?
The prey population may increase.
What is a group of organs working together to perform a specific function called?
An organ system.
In the food chain grass → grasshopper → frog → snake, which organism is the secondary consumer?
The frog.
Why does the amount of energy decrease as it moves from one trophic level to the next?
Organisms use energy for life processes, and much is released as heat.
Why is an energy pyramid always upright?
Because energy decreases at every trophic level.
What may happen to herbivores if most plants in a field are removed?
Their population may decrease because of a lack of food.
Arrange these levels from smallest to largest: organ, cell, tissue, organism.
Cell → Tissue → Organ → Organism.
At which trophic level does a tertiary consumer usually feed?
The fourth trophic level.
If producers store 10,000 units of energy, approximately how much energy reaches primary consumers using the 10% rule?
1,000 units of energy.
Why are there usually fewer top predators than producers in an ecosystem?
Because less energy is available at higher trophic levels.
In a lake, algae are eaten by small fish, which are then eaten by large fish. How does energy move through this food chain?
Energy moves from algae to small fish to large fish, decreasing at each transfer.
The heart, blood vessels, and blood work together to transport materials throughout the body. What level of organization do they form?
The circulatory system, an organ system.
In the food chain grass → grasshopper → frog → snake → hawk, identify the producer and the tertiary consumer.
Grass is the producer, and the snake is the tertiary consumer.
If producers contain 5,000 kJ of energy, approximately how much reaches secondary consumers using the 10% rule?
50 kJ of energy.
An ecosystem has 20,000 kJ of energy in producers. Using the 10% rule, how much energy reaches secondary consumers?
200 kJ of energy.
A lake has 15 g/m² of phytoplankton and 45 g/m² of zooplankton. If the zooplankton biomass decreases to 10 g/m² while phytoplankton remain at 15 g/m², what type of SPECIFIC ecological pyramid exists between these two groups now? clue: 3 words
upright biomass pyramid