Use molecule models to show how antacid molecules get rid of heartburn.
Bees can talk to each other with smelly molecules, called pheromones.
Students squeeze and sniff each of the bottles. Ask them what the smell makes them think of. (Likely lemon, banana, cheese and nothing.)
When a bee smells these same molecules it thinks of something quite different. Students match the molecule labels on each bottle with the molecules on the sheet to find out what each of these molecules means to a bee:
This might smell like bananas to you (banana smell), but to a bee it means war. This molecule signals bees to attack an intruder.
This molecule says it's moving day to a bee (lemon smell). Bees smelling this molecule swarm and move to a new hive
Feel alarmed when you smell this? A bee would (cheesy smell). Guard bees release this molecule to call for help when there is an intruder.
Although we humans can't smell this molecule (oxodecanoic acid, so use empty bottle), it is a perfume for bees. Queen bees release this molecule to attract males.
It may seem strange that other animals communicate with smell molecules. We mostly use our other senses to communicate.
Many creatures communicate with smell molecules.Dogs use smell molecules to mark territories. Ants leave pheromone molecules for each other to show the way to food.
Put 10 drops of fake stomach juice into each of two cups. Stomach juice contains loose hydrogen atoms.
Add a drop of dye to both cups of fake stomach juice. The color of the dye shows you the number of loose hydrogen atoms in the stomach juice.
How many hydrogen atoms are there in stomach juice?
Real stomach juice, like the fake stomach juice in your experiment, has lots of loose hydrogen atoms in it. Your stomach uses the loose hydrogen atoms to digest food. But sometimes stomach juice spills into the tube above the stomach. Hydrogen atoms are not meant to be in the tube above the stomach, and cause a burning feeling. This pain is called heartburn. When we get heartburn, we take an antacid.
Take a small piece of antacid and grind into a powder with the mortar and pestle. Dip a wooden stick into one of your cups of stomach juice to make it wet. Pick up some of the antacid powder with the wet stick. You only need a small amount.
Mix the antacid powder into one of your cups of stomach juice and dye. Leave the other cup alone. Keep mixing until the stomach juice changes color. Be patient — it may take a minute. Compare your two cups. What did the antacid do to the number of hydrogen atoms in the stomach juice? (Look at what colour the dye turned and infer what has happened to the number of hydrogen atoms).
How did the antacid take away the hydrogen atoms?
The antacid contains carbonate molecules. Find carbonate in the active ingredients on the antacid bottle. The carbonate molecules capture the loose hydrogen atoms to make a different molecule. (Students can build the molecules to see the reaction: CO3 + 2H -> CO(OH)2
How do antacids get rid of heartburn?
Just like in your experiment, the carbonate molecules in the antacid capture the loose hydrogen atoms in your stomach tube and the burning pain of heartburn goes away.
antacid = "anti-acid": Antacids get their name because they remove (or neutralize) acid, which is the same as removing hydrogen atoms.
Tested with family groups of adults and children of all ages.
Materials in the activities
Students experiment with how water shapes the land in the erosion activity.
Discussion includes how sediments are carried downhill by the water and deposited in the "ocean", and then as the layers build, get compressed into sedimentary rock.
As tectonic plates push together, sometimes they both buckle upwards to form mountain ranges.
Sedimentary uplifting activity to show what happens to sedimentary rock layers as they are uplifted.
Discuss cycle of sedimentation, uplifting, erosion.
It happens over millions of years.
Add weathering activity.
Add sedimentary sand art activity?
Life is diverse and can be grouped.
Show poster of Tree of Life. It shows many many living things, the lines connecting how similar they are to each other. Like a family. We are all related to each other, even bacteria.
We are part of the group of animals with bones.
Today we’ll focus on the other parts of the tree, maybe parts that you are less familiar with.
Pond dipping activity.
What different animals you can find in the pond water?
Find each animal on the Tree of Life
e.g. Daphnia and shrimp are Crustaceans, mosquito larva an Insect (Exoskeleton, legs), leech an Annelid (no legs, segments)
Now we’ll look at another part of the Tree of Life: plants.
Play a game that helps you identify different plants at your school.
e.g. Moss, Gymnosperm (Sequoia), Angiosperms: Yucca (monocot) and flowering plants (dicots).
After students are familiar with all the plants in the game, tell them:
Mosses are the oldest land plant on earth.
Mosses and conifers were around with the dinosaurs.
BONUS challenge:
Look at the leaves of these plants (point out). Find the veins in the leaves (which plants get their water through. Some of those veins are branching, some parallel (alongside each other). Find one of each.
Wrap:
Parallel veins are monocots. This group includes grasses and orchids.
Branching veins are dicots. This group includes all flowering plants.
Plants are many and varied, as is all life on Earth. We classify it to help understand it.
The Biodiversity lesson has some of the same activities, but with a different discussion focus.
Hand out a bone to each student and ask them to walk around and find others with similar bones.
Bones to hand out (or subset):
shoulder blades (2) humerus (2) fused ulna/radius (with elastic holding them together) (2)
fused front toe (metatarsal) bones (2)
pelvis (1) femur (2) tibia (the tiny fibula is absent) (1)
fused back toe (metatarsal) bones (1)
back (lumbar) vertebrae (4) and tail bone (fused sacral vertebrae) (1)
chest (thoracic) vertebrae (4 or more) and associated ribs (4 or more)
neck (vertical) vertebrae (6)
Students circle around a sheet to assemble the deer skeleton together, students adding their bones when asked. Older students can direct the assembly themselves, optionally using an image.
Students do not step on the sheet unless told to.
Start with the skull, then cervical vertebrae to continue down spine. Then add shoulder blades, front legs. Last add pelvis, back leg (part of one bag leg missing).
Discuss who might have taken the leg away (bobcat, coyote, fox, bald eagle) and imagine the scenario of a scavenger finding this big meal!
Find the gnaw marks on a bone where likely a rodent chewed. Likely shrew, mouse, vole or rat.
Find the missing tooth, and the ones that have overgrown on the other side without being worn away. They would have been digging into the gum giving the deer pain, and maybe an infection.
Discuss what happened to the skeleton once most of the meat had been eaten by other animals after it died - the decomposers and bacteria that cleaned the bones.
Draw up a food web linked to the deer as each species is mentioned.
Note all the life cycles that are linked to the life cycle of the deer.
If the students are getting wiggly sitting so long, take the skeleton apart bone by bone, asking students to find the equivalent bone in their bodies. They can stand up for much of this, wiggling each part of their bodies in turn.
The skeleton is probably a white tailed deer, the most common deer in Virginia.
A few white tailed deer facts, from this link: http://www.fcps.edu/islandcreekes/ecology/white-tailed_deer.htm
White tailed deer is a herbivore, eating green plants in the Summer; acorns, fruits and nuts in the Fall; and twigs in the Winter. They also eat fungi when they can find it.
They have few predators. Most commonly humans, sometimes fox and bald eagle.
They can run up to 60 km per hour. They are good swimmers. Their leap can be 2.5m high and 9m long.
The skeleton can be used for a comparative anatomy study, as in the skeletal system lesson plan.
Image comparing horse (similar to deer) and human skeletons, showing the same bones in each: https://i.pinimg.com/originals/64/b8/f4/64b8f401376e3cf8eb012c9de816b3c…
White tailed deer bone photos at https://russellboneatlas.wordpress.com/home/white-tail-deer-bone-atlas/
Start with modelling why we have seasons.
One way of getting through the winter is to hibernate.
Students rotate between three stations (5 mins or so each):
Fur study
Look at real fur, to find the guard hairs and the fluffy underfur.
Fur for keeping warm
Feel a bottle of iced water through fur and cloths of different thicknesses.
Fat for keeping warm
Feel a bottle of iced water through a layer of fat.
Both the fat and fur stop heat from leaving your hand, so they keep it warm. They are insulators.
Bears have thick fur and a layer of fat to keep warm.
The fur and fat layers both get thicker before hibernation.
The fat is also an energy reserve for the bears. At the end of hibernation a lot of the fat has gone, as the body has used it up.
The fur also protects against wet and wind.
End with Bear food as a demonstration. Add food to a scale until it tips (at 5kg), to show just a snack for a black bear before it hibernates.
Other activity ideas:
1. Feel our heart rate and our breathing rate. When a bear hibernates its heart rate slows down (from 50bpm to 10bpm) and it breathes less (one breath every 45 seconds).
Take our temperature. When an animal hibernates its temperature drops.
2. Watch webcam of Grouse Mountain grizzly bears hibernating.
https://www.grousemountain.com/web-cams/bear-den-cam
They hibernate for about 4 months.
Bears lower heart rate to a third, but only drop body temp by a degree (like us at night).
Dormant bears do not eat, drink, urinate or defaecate, the heart rate drops from 50–60 beats/min to 8–12/beats min, and oxygen consumption is only 32% of that of actively foraging bears.
3. Lots of bear videos, and bear vocalizations at www.bear.org
Other hibernation info:
Dry fluffy snow on top of a den also holds air, which stops heat from leaving the den.
Bears need water during hibernation - they get it from their body fat, when the fat molecules are broken down for energy.
If casts or stamps are available, make animal prints, and optionally your own hand print.
Alternatively, print out a life size bear print. e.g from here: https://wildlifeillinois.org/discover-animal-signs/black-bear-tracks/
Measure how long the animal footprint and your handprint is, to compare their sizes.
Record the number the toes or fingers. Do they have the same number of fingers/toes as us?
Make other comparative observations.
Note:
Often the animal footprint is only the front part of their foot, as they walk on their toes. If so, infer how long the real foot might be.
What shows up on the bear print that does not show up on ours? Claws.
Hold the bottle of iced water, to feel how cold it is.
Then wrap the bottle in each cloth in turn, and feel whether the cloth can keep your hand warmer.
(Note that if your hands get very cold from the ice, it will be hard to tell what the cloth does, so encourage students to use each hand in turn to give them time to adjust between each test.)
Students should find that the thicker, more furry, cloths keeps their hand warmer.
The air trapped in the thicker fibres insulates from the cold (i.e. it prevents heat from moving away from your hand).
Animal fur and feathers trap air to keep animals warm, sometimes from extreme cold.
Local animals with thick fur include bears, otters.
Bears moult annually in the early summer. They shed both their underfur and outer guard hairs, leaving only a short, sleek summer undercoat. Their new coat is growing in as the old one is being shed, so that by fall they have their thick, luxurious coats once again.
www.americanbear.org
Before the lesson make bags of fat:
Put half a block of lard in a medium ziplock baggie, and flatten it out.
Zip closed, then zip inside a second baggie.
Make a second control set with no fat: two baggies, one inside the other.
Hold the fat bag on your hand, then place a bottle of iced water on top of it.
Do you feel cold? (No)
Then do the same with the control bag. Do you feel cold? (Yes)
The fat is insulating and will stop you from feeling cold.
(Traditional 'blubber glove' has the same baggies of fat but you can put your hand inside: https://stevespangler.com/experiments/blubber-gloves/
I found that with young students, iced water often spilled into a blubber glove when they pushed it into the iced water.)
When bears hibernate, and the temperature outside is really cold (way colder than this water). They have a layer of fat under their skin which insulates them from the cold (it stops the cold from leaving their bodies).
Feel your fat under your skin by pinching your skin. Your fat is less than a cm thick. Hibernating black bears have a fat layer about 4cm thick. Polar bears have a fat layer up to 11 cm thick.
Background information: heat moves through fat half as fast as through muscle or other kinds of water-based body tissue. But for animals keeping warm, passive heat conduction rates is probably less important than controlling the paths of blood flow through the body e.g. using counter-current systems. Fat tissue near the skin can survive for hours without any blood going through it.
Original activity design:
Students put one index finger in a cut off disposable glove finger, and the other in a glove finger coated in fat (vaseline).
Students put both fingers in the water, and wait until one feels cold. They record which stayed warmer longer.
