6th grade · Science · Unit 9 of 17
Ecosystems
Living and non-living parts
What your child practices
Biotic and abiotic parts of an ecosystem, how they interact, and the limiting factors and carrying capacity that decide how many organisms an ecosystem can support.
Texas Essential Knowledge and Skills (TEKS) teks student expectation: 6.12(A); 6.12(C) · biotic and abiotic factors, competition, and organisms, populations and communities
How we explain it
Children can open this short lesson before they practice.
- Biotic parts are living (plants, animals). Abiotic parts are non-living (water, wind, rocks, temperature).
- A limiting factor keeps a population from growing, like food, water or nesting sites.
- When a population outgrows its food, some starve and numbers drop.
- A change in one part, like an invasive plant, can affect many others.
Example: Is sunlight biotic or abiotic? Sunlight is not alive. Answer: abiotic
Ecosystems in Texas
In the Texas Essential Knowledge and Skills (TEKS), this is unit 9 of 17 in 6th grade Science, after Stored Energy and before Biodiversity.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Source: Texas Education Agency (TEA)
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
Which is the best example of a limiting factor that is not about food?
- a shortage of nesting sites for cavity-nesting birds
- a long, warm summer with plenty of rain
- more insects hatching in spring
- an increase in plant growth
a shortage of nesting sites for cavity-nesting birds
Hint: Space and shelter limit populations as well as food.
Question 2
Why can a small pond support fewer fish than a large lake?
- It has less space, food and dissolved oxygen
- Fish need less food in ponds
- Pond fish are always larger
- Ponds have no producers
It has less space, food and dissolved oxygen
Hint: A bigger ecosystem has more of the resources that limit a population.
Question 3
Which of these is a biotic component of a pond ecosystem?
- water temperature
- sunlight
- dissolved oxygen
- algae
algae
Hint: Biotic parts are living things. Algae are living; the others are non-living conditions.
Question 4
What is an ecosystem?
- All the carnivores in a region
- A network of interactions among living things and their non-living surroundings
- Only the plants that grow in one place
- A group of animals of the same species
A network of interactions among living things and their non-living surroundings
Hint: An ecosystem includes both the living (biotic) and non-living (abiotic) parts, and the ways they affect each other.
Question 5
An invasive plant crowds out native plants. Why does this change the ecosystem?
- Invasive plants never compete with others
- The abiotic parts of the ecosystem disappear
- Native plants lose light, space and nutrients, and the animals that eat them may be affected
- Native plants gain more sunlight
Native plants lose light, space and nutrients, and the animals that eat them may be affected
Hint: Invasive species compete with native ones for the same limited resources.
Question 6
Biotic or abiotic? Sort each part of an ecosystem.
Sort into: 🌱 biotic (living) · 🪨 abiotic (non-living)
- 🍄a mushroom
- ☀️sunlight
- 🪨a boulder
- 🌬️wind
- 🦠bacteria in the soil
- 🌳a maple tree
- 🐸a frog
- 💧water in a stream
🌱 biotic (living): a mushroom, bacteria in the soil, a maple tree, a frog · 🪨 abiotic (non-living): sunlight, a boulder, wind, water in a stream
Hint: Biotic parts are living things (plants, animals, fungi, bacteria). Abiotic parts are the non-living things, such as sunlight, water, air, rock and temperature.