Archive for the ‘Life Cycle’ Category

The Nitrogen Cycle

Posted by admin under General, Life Cycle

Nitrogen is found throughout the soils and atmosphere in many different, organic and inorganic, forms. The Nitrogen Cycle is the process by which atmospheric nitrogen  enters the soil, is transformed by microbes, and re-enters the atmosphere (volatilization) and plants (assimilation).

How Does Nitrogen Enter the Soil?

Before nitrogen can be used by plants, it must enter the soil.  Atmospheric nitrogen is forced to the ground by rainfall. Also, urine, solid and liquid waste from living organisms and living organisms that have died are deomposed by bacteria and fungi.  The nitrogen from these sources then enter the soil. Commercial fertilizers are another source of nitrogen.

What Happens to Nitrogen in the Soil?

Plants cannot use organic nitrogen. Bacteria and fungi are needed to transform this unusable organic nitrogen into a usable form.  Although most nitrogen fixation is completed by bacteria, some is accomplished through lightning strikes. Since ammonia is fatal to most plants, bacteria convert this ammonia (NH4) into nitrates (NO3) and nitrites (NO2). At this time, the nitrogen can be assimilated into the plant, leached into the ground water or be transformed into a gas and re-enter the air.

In very wet soils, the oxygen content is low. The bacteria in these soils take the oxygen out of the nitrates (NO3) and produce nitrogen gas. This process is call denitrification.  Through a process called volatilization, the gas re-enters the atmosphere.

Praying Mantid Eggcase

Praying Mantid Eggcase

What is the difference between complete and incomplete metamorphosis in insects?

Incomplete and complete metamorphosis differ in the number of life cycle stages insects go through during their transformation from egg to adult. Complete metamorphosis has 4 life cycle stages and incomplete metamorphosis has 3 life cycle stages.

Complete Metamorphosis

Complete metamorphosis has four distinct life cycle stages: egg, larva, pupa and adult. Examples of insects that go through complete metamorphosis are butterflies, silkworms, mealworms and ladybugs. The larva can be worm-like, although you can still see the six legs. The larvae for moths and butterflies are called caterpillars. Maggots are the larval stage of flies. The larvae eat constantly and grow rapidly. A hard, protective case forms around the larva…this is the pupa stage. The pupa stage for a butterfly is called a chrysallis. The pupa stage for a moth is called a cocoon.

Incomplete Metamorphosis

Incomplete metamorphosis only has three life cycle stages: egg, nymph, adult. The nymph looks similar to, but a smaller version of, the adult. The nymph is also wingless. Examples of insects that go through incomplete metamorphosis are stinkbugs, earwigs, crickets, grasshoppers, cockroaches, ants and praying mantids.

Keep the lid over your plate to prevent contamination.

Keep the lid over your plate to prevent contamination.

All living organisms require energy. They can get their energy from multiple sources: organic chemicals(carbon containing compounds), inorganic chemicals and light. Bacteria use organic chemicals, such as, sugars, starch, protiens and fats to grow. Bacteria are called heterotrophs.

Most bacteria grow best at normal, human body temperature (98-99 degrees F). When growing the bacteria, incubate at a temperature as close to this as possible. The bacteria will grow slower at lower temperatures.

Aseptic technique is the process of growing and transferring bacteria without contaminating the culture by touching or breathing on the sample.

Nutrient agar is a general purpose prepared media and grows many types of bacteria and fungi. If you have a specific bacteria culture, you can spread the bacteria on the plate using a sterile swab or innoculating loop. The bacteria will grow and become visible in 24-48 hrs. If you would like to determine the types of bacteria growing on a sink, chair, table or other areas, a sterile swab can be used to rub across the area you would like to test. After the sample is taken, you can transfer the bacteria to the nutrient agar plate by swiping the swab across the surface of the agar plate. After 24-48 hrs, you may find many, different looking colonies growing on the nutrient agar plate. Each type of bacteria look a little different (color, shape, size) when they grow.

Earthworm Lifecycle

Posted by admin under General, Life Cycle

Earthworm Lifecycle

A species of the earthworm can be found on every continent in the world. They burrow through soil and help keep it healthy. Some species of earthworm can grow over 13 feet long, all though most are a lot smaller than that. Earthworms have been dissected in science rooms throughout the world, although if dissection is not an option, you can use lifelike plastic figures to represent the earthworm lifecycle.

blue earthwormearthworm

Earthworms have both organs needed for reproduction; the term used for this is hermaphrodite. When earthworms mate they lay next to each other and pass mucus like substance that allows each worms organs to be fertilized. After the earthworms mate they form eggs inside their bodies, then the worms separate and form cocoons which seal when they rolls off of the worm. The cocoon is buried underground and the hardened walls protect the forming worm.

The worms hatch as smaller earthworms that lack reproductive organs; this is the main difference between newly hatched worms and the fully developed. The worms start to develop reproductive organs after they are hatched. They are able to use their reproductive organs at around 12 months. Earthworms can sometimes live for more than 10 years depending on the species. In the United States earthworms range in color from red to brown, and in other countries they can be blue or green.

Check Out These Large Earthworms

When an adult butterfly emerges from its chrysalis, it secretes a red liquid that often drips down to the bottom of the habitat.  This is not blood.  It is actually a liquid known as meconium that is the natural secretions created while in the chrysalis.  This is natural and you should explain this to children during a butterfly life cycle project so that they do not think the butterfly is injured or that something is wrong with the experiment.

When butterflies emerge from the chrysalis, they are considered adult butterflies.  Care and feeding of adult butterflies is important to successfully complete a butterfly life cycle experiment.  Adult butterflies do not have jaws that allow them to chew plant material as they did when they were caterpillars.  Instead, they have a long, straw-like tongue called a proboscis through which they can consume liquid material. Butterflies are an example of an insect that goes through complete metamorphosis.

The caterpillars diet normally consists of one type of plant, depending on the species. The most popular butterfly used in classroom studies is the Painted Lady, Vanessa cardui. They are available through many different sources and they are a cost effective option. In nature, the larva feed on the mallow plant. In classroom studies, a prepared diet is the best option. The caterpillars each constantly during this time period. The larval stage lasts approximately 4 weeks. The habitat should not be too large as this will make it difficult for the caterpillars to find the food source. If this happens, the larva could starve. One unusual characteristic of the caterpillar is that it has 8 pairs of legs to assist in climbing. After the last molt, only the front 3 pairs will remain.

After the 3-4 weeks spent as a caterpillar, the larva will attach itself upside down and form the crysalis. When the chrysalis has hardened, they should be transferred to a larger container, normally a net type habitat. The filter paper that the larva attaches to can be attached to the top of the net using a paper clip. In 7-10 days, the adult butterfly will emerge.  A few hours will pass before the adult is ready to fly.

When your butterflies emerge from their chrysalis, you should place a shallow container of sugar water into the bottom of their habitat or butterfly net.  They will consume this during the week to 10 days you have them in the habitat prior to release.

Though butterflies can adapt to a fairly wide range of temperatures, it is best to keep their habitat at room temperature and away from direct sunlight through windows.  The time periods listed above can vary depending on the temperature, amount of food and the concentration of larva.

Ant History

Ants are insects that evolved from wasp-like creatures over 100 million years ago. Today there are over 12,000 species of ants that have been classified.

Ants form colonies that range in population from a few dozen living in small natural cavities to millions that live in larger structures they build in the ground. The colonies consist of three types of ants. Sterile, wingless females, fertile males, and fertile females referred to as queens. The sterile female ants serve as soldiers or workers in the colony.

Ants work together in colonies to build their habitat and recreate. The process can be fascinating to watch for children and adults alike. Due to the fact that most ant colony behavior takes place beneath the ground, humans must use ant habitats or ant farms to observe ant colony behavior.

Ant Farming

The ant farm is designed to study ant and ant colony behavior by offering a great observation tool for the classroom or just for fun. Myrmecologists study ant behavior, and with an ant farm you can take a look into the world of myrmecology (the study of ants).

Close up of an AntTunneling Ants

Ant Farm Types

The Ant Farm by Uncle Milton is a classic ant farm that has a green farm scene with a clear viewing pane surrounded by a green frame. The farm is usually filled with sand, dirt, or other media. These ant farms have a low price point making them accessible to classrooms and families of all budgets. In order to properly care for your ants, you will need to open the ant farm and make sure the ants have food and water. The down side is that this increases the chances of the ants getting out of the farm and into places you do not want them.

In recent years the Ant Farm has been modernized with improvements to visibility. A modern alternative ant farm is the AntWorks Illuminated Habitat

AntWorks Illuminated Habitat
Ant FarmIlluminated Ant Farm

The AntWorks ant farm is completely see through thanks to a gel that NASA developed when studying ants tunneling at zero gravity. The gel holds nutrition and water so that you do not have to provide the ants with nourishment. The AntWorks Illuminated Habitat is available with either red, green, or blue gel. The setup also includes LED lighting in the base so that you can view the ants at night. All of this is housed in a tightly sealed 6.5L x 6.0W x 1.25D clear acrylic habitat to minimize ants escaping into your house, lab, or classroom.

Set Up

Set up of the green AntWorks Illuminated ant farm was easy using the provided instruction manual. After assembling it and testing the LED lights the next step was to go out and find some ants. There are two options for getting your ants, you can either send in the coupon provided with the kit or find your own ants. After finding the ants, they were put into the ant farm which was covered with a towel for 3 days to allow the ants to get used to their new home. After adjusting to life on the ant farm the ants have created a spectacular tunnel system that looks even better in the dark with the LED lights on. They are fascinating creatures to watch and learn from.

For more information, Wikipedia has in depth information about insects including ants . You can always call Heath Scientific as well.

It has been five days now since we planted a sunflower seed covered in our post Growing A Sunflower Seed – Childrens Learning Activity and this morning provided evidince that germination was successful as a couple of small green sprouts could be seen in the potting soil.  We removed the seran wrap from the top of the paper cup, added a few teaspoons of water, and placed our Sunflower sprout in the window sill to garner some spring sunlight.

We will provide another update once our Sunflower is ready to be planted in a bigger container and when it blooms.

sunflower-sprout

The growth stages of a plant can be fascinating for children as they are able to watch a tiny seed turn into a living organism. In some cases the result will display beauty like the sunflower in this activity or the result will be edible like vegetables produced by a tomato plant or corn stalk.  Though a plant learning exercise can require patience, it does provide both parent/teacher and child the routine activity of checking on the plant’s progress on a daily basis.

Materials Required for ‘Growing A Sunflower’

  • 3 sunflower seeds
  • 1/2 cup of potting soil
  • a small paper cup
  • 1/3 cup of luke warm water
  • saran wrap to cover the cup during germination

The Activity

With all items in the materials list present, the child should be introduced to the seeds.  Then, the child can be shown the following video that will give them a vision of the sunflower learning activity and its outcome.

Once this is complete, the following steps should be followed.

1)  Place potting soil into the paper cup.  Do not pack it as you will want the soil to be loose.

2)  Take a pencil or other narrow object and create three holes in the dirt.

3)  Have the child place a seed in each hole and then cover with a little more soil.

4)  Pour the water into the cup and then cover with saran wrap.

5)  Place the cup on a window sill or classroom cabinet surface.

Sunflower Germination

The seeds will need to go through a germination process over the next week to two weeks.  Water is extremely important during this process.  This is why the cup has been covered with saran wrap in order to keep moister in the cup.  Once the germination process is completed, the saran wrap will need to be removed.  You can do one of two things: the first is to simply remove the saran wrap after the first week; the second is to wait until you see the seed sprouting through the dirt and then remove the wrap.

Sunflower Growth

After germination, place the sunflower in a well-lit area and provide water on a daily basis.  DO NOT over water your sunflower.  Once the sunflower has several inches in height, it should be transplanted to an outside flower pot or garden as your new sunflower will need room, sun, and water to flurish.

Life Cycle of a Butterfly

Posted by admin under Life Cycle

Emerging monarchThe butterflies cycle of life is very different from the rest of nature. The butterfly’s lifecycle has four stages; which include Egg, Larva (caterpillar), Pupa (cocoon), and Adult.  Butterflies are important to nature because they are an agent of pollination.  This means they pollinate flowers, which happens when pollen grains are transferred from the male to the female part of the flower.

Egg

Butterfly eggs consist of a hard outer shell; the outer shell has wax on the inside to prevent it from getting too dry. These eggs are usually affixed to a plant leaf with glue that quickly hardens. The egg stage lasts for a few weeks.

Caterpillar

During the larva stage the caterpillar consumes plant leaves, finding and consuming the plant leaves is how the caterpillar spends most of its time. Many caterpillars have markings on their rear end that look like eyes. This along with ability to produce chemicals that smell or are toxic offers defense from birds and other predators.

Pupa

This is the stage in which the caterpillar searches for a desirable location in which to turn itself from larva into a pupa. The caterpillar will attach itself to a branch or limb and moult for the last time. Metamorphosis takes place and a butterfly emerges at the end of this cycle.

Adult Butterfly

Adult Butterflies are not able to fly until their wings gain blood circulation and completely unfold; this usually takes 1-3 hours depending on the type of butterfly. Without a net or other type of protection they are very vulnerable while waiting for their wings to function.  The adult is known as the imago, as an adult the butterfly gains the ability to reproduce. The adult butterfly has 4 wings and 6 legs.

Learning Activity for Children

Butterflies are fascinating for children because of their beauty and the simple fact that they fly.  Rarely can a book teach a child the stages of a butterfly’s life cycle better than simply experiencing it.  Raising butterflies through their life cycle is a fun educational activity for children.  To successfully raise butterflies through their life cycle, you will need:

  • Painted Lady Caterpillars with food.
  • Vials and lids
  • And a two foot hanging butterfly net

Heath Scientific provides these supplies along with complete instructions in a Live Butterfly Classroom Kit .  Though designed for the classroom, it is a great activity for parents and children of all ages.