Making Fossils

What You Need:

  • crayfishModeling clay
  • Plaster of paris
  • Shells (or other hard objects to make imprints)
  • Paper towels or small plates
  • Bowls/strong spoons to mix plaster
  • Water

fossils

What Do You Do?

  • Take a ball of clay and flatten it a bit before making the impression in it.
  • Place the clay on a paper towel or plate with your name on it.
  • Use your shell (or other object to fossilize) and push it into the clay to make a deep imprint.
  • Remove the object and make sure the imprint is clean.
  • Pour enough plaster of paris in it to fill the impression, careful not to overfill and drip down the sides!
  • Let the plaster sit a few hours (or even overnight) to set and harden.
  • Remove the modeling clay from the now hardened plaster–this is your fossil!

What Happened?

Fossils are the preserved remains of plants or animals. For such remains to be considered fossils, scientists have decided they have to be over 10,000 years old. There are two main types of fossils, body fossils and trace fossils. Body fossils are the preserved remains of a plant or animal’s body. Trace fossils are the remains of the activity of an animal, such as preserved trackways, footprints, fossilized egg shells, and nests.

When asked what a fossil is, most people think of petrified bones or petrified wood. Permineralization is a process. For bone to be permineralized, the body must first be quickly buried. Second, ground water fills up all the empty spaces in body, even the cells get filled with water. Third, the water slowly dissolves the organic material and leaves minerals behind. By the time permineralization is done, what was once bone is now a rock in the shape of a bone. Unlike what you see in cartoons, dogs wouldn’t be interested in these bones.

When an animal or plant dies, it may fall into mud or soft sand and make an impression or mark in the dirt. The body is then covered by another layer of mud or sand. Over time, the body falls apart and is dissolved. The mud or sand can harden into rock preserving the impression of the body, leaving an animal or plant shaped hole in the rock. This hole is called a mold fossil. If the mold becomes filled over time with other minerals the rock is called a cast fossil.
A simple experiment can show you how this works. Take some clay and press a seashell or some other object into the clay. Pull the sea shell out of the clay any you will see a detailed impression of your seashell in the clay. If, over time, the clay hardens into rock the result would be a fossil mold. But really, who has millions of years to wait to make their own fossil? Here’s the quick way. Pour plaster of Paris, dental stone, or other plaster into the mold. Wait for it to harden and you have just made your own cast fossil.

Another type of fossil is a resin fossil. Resin is sometimes called amber. Plants, mostly trees, secrete sticky stuff called resin. Sometimes insects, other small animals, or bits of plants get stuck in the sticky resin. The resin hardens overtime and is preserved in rock making a fossil.

Examine Cacti

What You Need:

  • 14612922-cacti-plantsMany different cacti samples
  • Hand lenses

Cacti Adaptation

What Do You Do?

  • Use your hand lens to thoroughly examine each type of cactus.
  • Draw each cactus in your lab book.
  • Describe how each cactus might survive in the harsh desert.
  • What adaptations does it have to help it?

What Happened?

Cacti have many adaptations that allow them to live in dry areas; these adaptations let the plant collect water efficiently, store it for long periods of time, and conserve it (minimizing water loss from evaporation).

Cacti have a thick, hard-walled, succulent stem – when it rains, water is stored in the stem. The stems are photosynthetic, green, and fleshy. The inside of the stem is either spongy or hollow (depending on the cactus). A thick, waxy coating keeps the water inside the cactus from evaporating.

Many cacti have very long, fibrous roots, which absorb moisture from the soil. Some, like ball cacti, have shorter, more compact roots that absorb dew water that falls off the cactus.

Instead of leaves, most cacti have spines or scales (which are modified leaves). These spines and scales do not lose water through evaporation (unlike regular leaves, which lose a lot of water). The spines protect the cactus from predators (animals that would like to eat the cactus to obtain food and/or water). Areoles are circular clusters of spines on a cactus. Flowers bud at an areole and new stems branch from an areole.

Feathers!

Aquatic_Birds

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What You Need:

  • Feathers
  • Droppers
  • Oil
  • Water
  • Waxed paper
  • Hand lenses

What Do You Do?

  • Use the dropper to add small drops of oil and water onto the waxed paper.  How do they look different?
  • Next, drop some oil and water in different places onto the feather.  How does the liquid react with the feather?

What Happened?

Aquatic bird feathers are neatly arranged to repel water, and they use an oil to coat the feathers (similar to wax paper) which makes the water roll right off of them.

Cold Weather Adaptations

ColdAnimals

Materials

  • Plastic tuborca_spyhopping-noaa
  • Ice water (need lots of ice!)
  • Vaseline pouches (double walled baggies with vaseline between walls)

Forming a Hypothesis

  1. What problems have to be overcome for animals to survive in cold water?
  2. What possible advantage is there to living in the Arctic or Antarctic?
  3. How long does it take for adaptations to form?

Experiment

  1. Take turns within your group. Take your hand, and hold it underwater- how long you can hold it in the water?
  2. Repeat the experiment, this time putting one of the vaseline pouches on. Were you able to hold your hand under for longer?

What Happened?

Some animals migrate between warm breeding waters and cold feeding waters near Antarctica and in the Arctic. Do you know how whales keep warm when they are in very cold water?  They have a thick layer of fat under their skin called blubber. The blubber keeps them warm and also stores nutrients their body can use when they are in waters where there isn’t much food. Other marine mammals like seals and sea lions also have blubber.

Blubber helps keep animals warm because it acts as an insulator. An insulator slows down the transfer of heat, keeping the animal’s body heat from escaping into the water and protecting it from the cold.

The vaseline packs should have allowed you to keep your hands in the icy water much longer than when they are bare.  Vaseline acts just like blubber!

Best Bird Beak

What You Need:

  • Forceps060 Bird beak
  • Chopsticks
  • Slotted spoons
  • Salad tongs
  • Shredded wheat (slightly wetted with water)
  • Grapes
  • Cooked noodles
  • Sunflower seeds
  • Bowls

BirdBeaks

What Do You Do?

  • Get different types of “food” ready in bowls.
  • Assign each student in a group of 4 one type of “beak”.
  • In a given amount of time, have each student use their beak to collect as much food as possible.
  • Rotate the types of food between the groups, as well as the beaks within the groups, and tally up the collections.
  • Which beak worked best for each type of food?

What Happened?

Darwin was amazed by the variation in the characteristics of plants and animals he encountered on his journey. In any habitat, food is limited and the types of foods available may vary. Animals that have variations that enable them to take advantage of available foods will be more likely to survive. We call beneficial inherited variations adaptations. Adaptations are inherited characteristics that increase an organism’s chance of survival. Those with the most helpful adaptations will be the most likely to live long enough to pass on their genes to the next generation. This process ensures that beneficial adaptations will continue in future generations, while disadvantageous characteristics will not.

Kidney Models

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What You Need

  • Funnels
  • Graduated cyiinders
  • Filter paper
  • Cups
  • Water
  • Baking cocoa
  • spoons

See the rest of this experiment »

Digestive System

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What You Need:

  • Orange juice
  • Saltine crackers
  • Ziploc sandwich bags

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Circulatory System–Zebrafish Embryos

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What You Need:

Circulatory System–Heart Rates

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What You Need:

Celery Lab (Phloem & Xylem)

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