Life Science

Homework for Class 8

Homework: Keep collecting, dehydrating, and pinning insects. You will need at least 12 pinned insects by the end of the school year, but you are welcome to collect as many more as you want!

Lecture: We continued our discussion of insects.

Some insects that live in societies are ants, bees, and wasps (which are all in the same family).

The queen bee lays eggs, while the drones' job is to mate with the queen. Worker bees (which is most of the bees in the hive) have a number of jobs, like taking care of the larvae (baby bees), build the hive, form wax, guard, and forage.

We can divide insects by the type of metamorphosis that they do throughout their life.

• Some insects do not go through any metamorphosis.

• Others go through incomplete metamorphosis. There are 3 stages to this: egg, nymph, and adult. Nymphs look similar to adults, but generally do not have functional wings. The nymphs cannot grow in their hard exoskeleton, so they have to shed it while they grow into an adult. When they shed their exoskeleton, we say that they "moult."

• Other insects go through complete metamorphosis. There are 4 stages to this: egg, larva, pupa, and adult. Larva do not look like adults, but look more like worms. Maggots, for example, are the larvae of flies and caterpillars are the larvae of butterflies. These larvae form a cocoon (or chrysalis) around themselves. In this stage, they are called a pupa. They emerge in their adult form.

Some of the benefits of insects are: pollinating flowering plants, making honey, feeding other animals like frogs.

Some of the disadvantages of insects are: eating crops (like locusts), spreading disease (like mosquitoes who spread malaria), or simply stinging us when we play outside.

Grasshoppers have a unique life cycle. If there are too many grasshoppers in an area, the young ones grow up larger and with much larger wings. These super grasshoppers can fly away from the area in swarms, and we call them locusts. The largest swarm of locusts ever recorded was Albert's Swarm in 1875. The swarm destroyed crops from Texas to Canada. It extended 200,000 square miles, with an estimated 3.5 to 12.5 trillion locusts.

Homework for Class 7

Homework: Complete "Homework Sheet 2" handed out in class and attached below. It is open-book, so refer to handouts and notes to answer the questions. These sheets are a huge chunk of your overall grade, so make sure to stay on top of them.

Lecture: Today we reviewed previous lectures on plants, then started talking about animals.

We divide animals between vertebrates (animals with a backbone) and invertebrates (animals without a backbone). Worms, slugs, and jellyfish are invertebrates. A large group of invertebrates is the Arthropods, which all have exoskeletons (a skeleton outside of their skin).

Types of Arthropods are:

1. Crustaceans: crabs, lobsters, shrimp, etc

2. Arachnids: spiders, scorpions, ticks, etc

3. Chilopoda: centipedes

4. Diplopoda: millipedes

5. Insects

There are over 900,000 types of insects. A few of the major groups are:

1. Beetles, ladybugs

2. Bees, wasps, ants

3. Butterflies, moths

4. Flies, mosquitoes

5. Dragonflies

6. Grasshoppers, locusts, crickets

7. True Bugs: cicadas, bedbugs, pond skaters, box-elder bugs, stinkbugs

We will talk more about insects next week.

Homework for Class 6 (after Fall Break)

Great work on the Tree Project!

Homework: During the break, complete the homework sheet I handed out in class (worksheet 1). Refer to your notes, my notes on this website below, and the handouts I gave you in order to fill out the homework sheet. This type of exercise will make up the bulk of your grade for the semester, so be sure to complete the homework sheet before next class.

Lecture: Types of Plants (continued), Flower Anatomy, and Photosynthesis

Types of Plants: Monocots and Dicots

Today we finally talked about seed-bearing plants. There are two types of seed-bearing plants: monocots and dicots. The main difference between them is how many "seed leaves" (called cotyledons) there are in a seed.

Memorize: Cotyledons are leaves in seeds.

"Mono" means "one" and "di" means "two," so a "mono"-cot has "one-cotyledon," whereas a "di"-cot has two cotyledons. Corn, for example, has only 1 cotyledon in each seed, so it is a monocot, while petunias have 2 cotyledons in their seeds so they are dicots. These cotyledons are absolutely essential while the plant is very young because they are the only way for the plant to make food before it grows true leaves.

Monocots are mostly grasses like common yard grass, prairie grass, wheat, and corn. Some flowers like iris are also monocots.

Dicots are all the remaining flowering plants like roses, violets, maple trees, ash trees, etc. There are a LOT of dicots.

Monocots and dicots have a few different characteristics. All monocots have parallel veins in their leaves, while dicots have branching veins. All monocots have flowers with petals in multiples of 3, while dicots have petals in multiples of 4 or 5.

Flower Anatomy and Seed Development

The center of a flower is called the ovary, which contains eggs. The carpel (also called the pistil) is a tube that sticks up out of the ovary. Thin tubes stick up around this called stamens, which hold pollen on their tops. Surrounding these are the petals. When a bee collects nectar and pollen from one flower, static electricity pulls pollen onto his hair, which he carries to other flowers. He cleans the pollen off himself, dropping it onto the sticky head of the carpel. The pollen grow tubes through the carpel until they meet the eggs in the ovary, thereby forming seeds. After this, the flower's job is done and it turns into a fruit.

Because apples don't fall too far from the tree, the sapling apple trees will have a tough time getting enough sunlight and water if they try to grow directly under their parent tree. This is why plants grow nutritious and delicious fleshy stuff around their seeds (the tasty part of an apple) so that horses and other animals will eat their apples, then deposit the seeds far from the tree when they are done digesting the apple. These seeds have an added benefit because they can grow in great fertilizer.

Photosynthesis

A plant's root system carries water (H2O) from the roots up to the leaves. Tiny holes on the bottom of leaves called stomata absorb carbon dioxide (CO2). Special cells on the top of leaves absorb energy in the form of sunlight. When they combine this energy, water, and carbon dioxide, they get two things: glucose (which is a sugar) and oxygen gas (which is what we need to breathe). Glucose is the plant's food, so this whole process is how a plant gets food.

Homework for Class 5

Complete the Tree Project. It is due in class next week. Bring your folder (blue or red) with all five worksheets, leaf and bark rubbings or presses, and tree sketches.

Lecture

Today we reviewed bacteria and their organelles, then discussed the simplest forms of plant life. Plants can be divided into those with seeds and those without seeds. Those without seeds can be divided based on whether they have distinct leaves, roots, and stems.

Algae, for example, have no distinct leaves, roots, or stems. Each cell needs to collect its own water, produce food, reproduce, etc. Each cell could hypothetically live on its own, so this kind of plant is like a collection of individual cells.

Mosses are an in-between case. They have some distinct leaves, roots, and stems, but not so much as other plants. They cannot grow very tall because they do not have a vascular system, which is a system that carries water throughout the plant (like a root system in more complex plants or the blood vessels in animals). Algae and mosses are both nonvascular plants. Since each cell needs to collect its own water, each cell needs to grow where the water is.

Ferns are an example of vascular plants. They have distinct leaves, roots, and stems. They produce spores instead of seeds, which makes them simpler than seed-bearing plants. Spores are small cells that are blown by the wind. If a single spore plants itself in the ground, it will grow as an exact copy of the parent fern (like a clone or a twin). If, however, two spores bump into each other, the child fern will be a combination of the parent ferns.

Homework for Class 3

In class, we covered everything the students will need in order to finish the Tree Project.

1. We identified the trees to the best of my ability while only looking at the leaves. I cannot be confident about my identification because I couldn't see the size/shape of the tree or the arrangement of leaves on the branches. Feel free to research and correct any of my identifications.

2. We covered how to estimate the size of a leaf using graph paper. 5 sheets of graph paper were provided.

3. We covered how to estimate the circumference of a tree by wrapping a cord around it then laying the cord flat and measuring it with a measuring tape. (You can also use a fabric measuring tape if you have one.)

4. We covered how to estimate the canopy of a tree (instructions handed out and attached below). 5 more sheets of graph paper were provided.

5. We covered how to estimate the height of a tree (another method is in the handout attached below).

Homework: Complete 1 worksheet for the Tree Project (handed out in class and attached below). You may use the student's sketch of the tree from last week for item 10 on the worksheet or choose a different tree. Note: The student should not do more than 1 tree before next class because I want to make sure they are doing it right before they go on. If the student is not able to complete it due to extraneous circumstances, please email me before our next class.