Pollination and the food on your plate

Science · Ecosystems & Habitats · ages 11-12

Name ______________________ Date ____________

Bees vanish from a farm one spring. Which crop on that farm is most at risk?
- The rice paddy
- The apple orchard
- The wheat field
Look at the chart. Which crop shows zero insect dependence?
- Oilseed rape
- Wheat
- Apples
What does a bee carry from flower to flower?
- Apple seeds
- Pollen
- Water
Every food crop needs insects to make fruit or seeds.
Circle one: True False
A farmer notices far fewer bees visiting his oilseed rape field this spring. What is the most likely result?
- The plants will grow taller than usual
- Nothing will change because oilseed rape doesn't need pollinators
- The plants will produce less seed and oil than usual
Suppose an orchard has 20 apple trees. Suppose without bees about 9 of every 10 trees fail to set fruit. About how many trees would still give apples?
Answer: ______________
Bee numbers drop sharply in an apple-growing region, and the next autumn apples cost far more in shops. What chain of events explains the price rise?
- Shops raised prices because they like bees
- Fewer bees meant fewer blossoms were pollinated, so fewer apples grew, and scarcer apples cost more
- Bees make honey, so apples are sweeter and cost more
Suppose in this model an apple tree has 15 open blossoms. Bees visited 9 of them, and only visited blossoms can grow into apples. How many blossoms will not grow into apples?
Answer: ______________
Which list puts the steps of an apple forming in the right order?
- A bee brings pollen, the blossom is pollinated, the blossom grows into an apple
- The apple grows first, then the blossom opens, then pollen arrives
- The blossom falls off, then the bee arrives, then the apple appears
Two farms sit side by side. Farm A grows only almonds, and Farm B grows only wheat. Bee numbers in the area crash. Which farm is in more trouble, and why?
- Farm A, because almond trees here lose far more yield without insects than wheat does
- Farm B, because wheat is a bigger plant
- Both farms are in exactly equal trouble

Answer key

For grown-ups. Fold this page away before handing over the rest.

Pollination and the food on your plate W1-mt_wWpa5fFDZP-s1

The apple orchard · Apple blossoms need insect visits to set most fruit. Wheat mostly pollinates itself and rice mostly pollinates itself, so both manage without bees.
Wheat · Wheat shows 0 percent and mostly pollinates itself, so it can set seed without insects. Oilseed rape at 30 and apples at 90 still set some seed without insects, but only wheat shows zero.
Pollen · As a bee feeds, pollen sticks to its body and rides along to the next flower. That delivery is pollination.
False · Some crops, like wheat, mostly pollinate themselves instead of needing insects.
The plants will produce less seed and oil than usual · Oilseed rape needs insect visits to set seed well. Fewer visits usually means a smaller harvest.
2 · Suppose 9 of every 10 fail. That is 90 percent of 20, which is 18 trees that fail, so 20 minus 18 leaves 2 trees that still give apples.
Fewer bees meant fewer blossoms were pollinated, so fewer apples grew, and scarcer apples cost more · Each link follows from the last: fewer pollinators means less fruit set, less fruit means scarcity, and scarcity pushes prices up.
6 · 9 of the 15 blossoms were visited, so 15 minus 9 leaves 6 blossoms with no bee visit and no apple.
A bee brings pollen, the blossom is pollinated, the blossom grows into an apple · The blossom must receive pollen before it can become fruit. Pollen delivery, then pollination, then fruit.
Farm A, because almond trees here lose far more yield without insects than wheat does · In the chart model, almonds show 100 and wheat shows 0, so a bee crash hits the almond farm harder. Wheat mostly pollinates itself and can still set seed.