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Cells and Systems 6-8 / Week 03 / Nature Day
6/6
Week 03 · Inside a Cell

Nature Day

Nature Day: Systems in the garden
// A cell is a system of parts
⏱ about 20 min

Nature Day: Systems in the Garden

Saturday morning, the crew takes the bag model and the hand lens out to the garden.

Rocket holds the bag up beside a leaf. "Every bit of this leaf is made of cells like this. Thousands of bags."

Raven turns the leaf over with the hand lens. "What do you notice? Lines, patterns, tiny bumps. Cells lined up in rows."

Nova hovers over a bird on the fence. "Feathers, eyes, wings," she says. "All cells. All with membranes and nuclei."

"And mitochondria, because flying takes energy," Rocket adds.

Raven writes in the log. "Look, do not touch. Then we check the seed jar." Nova hums. "Systems everywhere you look."

  1. A cell is a system. Its parts each do a job and work together to keep the whole cell alive.
  2. The cell membrane is the boundary that controls what enters and leaves. It is semipermeable.
  3. The nucleus houses DNA and acts as the command center. Mitochondria convert energy from food.
  4. The cytoplasm is a jelly-like fluid, mostly water, that holds the parts. The cytoskeleton gives the cell its shape.
  5. A model like the bag of water shows the parts and the boundary. It cannot show the jobs, and that is fine.
◇ FAMILY CELL-SPOTTING WALK
Walk a garden, park or block together. Each person picks one living thing: a leaf, a bird, an insect, a blade of grass.
For each one, say together: it is made of cells, and each cell has a membrane, a nucleus and mitochondria.
Guess which living thing has the busiest mitochondria. A flying bird? A resting snail? Talk about why.
Back home, check the seed jar together. Add water if needed and measure the longest root and stem.
For a grown-up
Outdoors, the crew looks at leaves, birds and insects from where they stand. Nothing is touched or picked.
Everyone washes hands after being outside or handling leaves or soil.
The recap facts come from the National Library of Medicine at medlineplus.gov and OpenStax at openstax.org. Others come from the National Human Genome Research Institute at genome.gov.
Safety first
Never touch a nest, an insect or an unknown plant or berry. Look from where you stand.
Nothing found outside goes in your mouth.
Wash your hands when you come back inside.
THINK IT THROUGH
  • Read the question.
  • Tap your answer.
A bird flaps hard to take off. Which cell part is busiest in its wing muscles?
A leaf is made of many cells. What does every one of those cells have?
Nature Day checkTrue or false?
Every cell in a leaf has a membrane.?
A bag of water is a perfect copy of a cell.?
Mitochondria convert energy from food.?
WHY THIS EXERCISESeeing real living things as collections of cell systems is the point of the week.
Draw the living thing you picked on the walk. Beside it, draw one of its cells with the four main parts labelled.
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