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Found at the Biology Corner Name __________________ Period ______
Sponges – A Coloring WorksheetSince sponges look like plants, it is understandable why early biologists thought they were plants. Today, we know that sponges are simple, multicellular animals in the Kingdom Animalia, Phylum Porifera. This phylum is thought to represent the transition from unicellular animals to multicellular animals. Most (but not all) sponges are asymmetrical and have no definite shape. Sponges, like all animals, are eukaryotic – meaning their cells have a nucleus. Porifera in Latin means “pore-bearer” and refers to the many pores or openings in these animals. Because of these pores, a sponge can soak up and release water. At one time, real sponges were used for cleaning and bathing. Today, most are artificially made.
All adult sponges are sessile, meaning they are attached to some surface. Since they cannot move, sponges cannot pursue their food. Instead, they are filter feeders, meaning they obtain their food by straining the water for small bits of food like bacteria, algae or protozoans.
Sponges exhibit less specialization (adaptation of a cell for a particular function) of cells than most invertebrates. The primitive structure of a sponge consists of only two layers of cells separated by a non-living jelly like substance. The outer layer of the sponge is the epidermis which is made of flat cells called epithelial cells. Color all the epithelial cells (B) of the epidermis peach or pink.
The inner layer consists of collar cells (A) whose function is to circulate water through the sponge. They do this by swishing their flagella which pulls water through the incurrent pore – water then travels out the osculum at the top of the sponge. As water passes through the sponge in this way, cells absorb food and oxygen and waste is excreted. Color the osculum (D) dark blue, the incurrent pores (C) light blue. Color the inside of the sponge where water circulates the same light blue as you colored the incurrent pores. Color all the collar cells (A) red.
In the jelly-like substance between the epidermis and the collar cells are cells called amebocytes – because they look like amebas. The job of the amebocytes is to travel around distributing food and oxygen to the cells of the epidermis. Because of the amebocytes, scientists believe that sponges evolved from protists. Color all of the amebocytes (E) green – look for them carefully.
The body of the sponge would collapse if it did not have some type of supporting structure. Some sponges have a soft network of protein fibers called spongin. Others have tiny, hard particles called spicules. Many of these spicules also stick out of the epidermis and provide the sponge with protection. Most sponges have a combination of spicules and spongin, the ratio often determines how soft or hard the sponge is. Search for and color all the pointy spicules (F) brown.
Reproduction for sponges can be accomplished both sexually and asexually. There are three ways for a sponge to reproduce asexually: budding, gemmules, and regeneration. Sponges can simply reproduce by budding, where a new sponge grows from older ones and eventually break off. Color the adult sponge (J) pink and all the buds (G) you can find red. Sponges can also reproduce by regeneration, where missing body parts are regrown. People who harvest sponges often take advantage of this by breaking off pieces of their catch and throwing them back in the water, to be harvested later. Finally, sponges can reproduce by creating gemmules – which is a group of amebocytes covered by a hard outer covering. Color the gemmule (H) yellow.
Sexual reproduction occurs when one sponge releases sperm into the water. This sperm travels to another sponge and fertilizes its eggs. The larva form will then swim to another location using its flagella where it will grow into an adult sponge. Most sponge species are hermaphrodites, they can produce both eggs and sperm.
Questions:
1. What did early biologists think sponges were? ______________________
2. Sponges belong to the Kingdom _________________ and the Phylum _______________
3. Sponges are [ unicellular or multicelluar ] and [ prokaryotic or eukaryotic ]
4. What type of symmetry do sponges have? ___________________________________
5. What does it mean to be sessile? ____________________________________
6. How do sponges get their food? ___________________________________
7. Water enters the sponge through the _____________________ and leaves through the
_____________________.
8. What is the job of the amebocyte? ________________________________________
9. What two substances give the sponge support? _________________________________
10. Tiny sponges growing from the main body of the sponge are called _________________
11. What is a gemmule? ___________________________________________________
12. What is a hermaphrodite? ______________________________________________
Label the letters on the diagrams

Label the letters on the diagrams

Found at www.biologycorner.com
Click here to view an animation of the endocrine system
The endocrine system is a set of hormone secreting glands within the body of an animal. The function of the endocrine system is homeostasis, communication and response to stimuli. The endocrine system regulates the internal environment of the animal for growth, survival and reproduction as well as allowing it to respond to changes in its external environment.
The endocrine system’s glands secrete chemical messages we call hormones. These signals are passed through the blood to arrive at a target organ, which has cells possessing the appropriate receptor. Exocrine glands (not part of the endocrine system) secrete products that are passed outside the body. Sweat glands, salivary glands, and digestive glands are examples of exocrine glands.

The other communication method in the body is the nervous system. Although there are differences between them, they complement each other in many responses, e.g., response to danger.
The difference between nervous and endocrine control are as follows:
1. Nervous response is faster.
2. Nervous response is shorter in duration.
3. Nervous response stops quicker.
Hormones
Most hormones are made of protein. They are called peptides. Peptides are short chains of amino acids; most hormones are peptides. They are secreted by the pituitary, parathyroid, heart, stomach, liver, and kidneys.
Some hormones are steroid based. Steroids are lipids derived from cholesterol. Testosterone is the male sex hormone. Estradiol, similar in structure to testosterone, is responsible for many female sex characteristics. Steroid hormones are secreted by the gonads, adrenal cortex, and placenta.
Hormones are usually slow to act but, once they act, they remain active for long periods of time and, also, their effects remain for a long time.
Endocrine Glands
There are 10 endocrine glands. As stated previously, other organs such as the stomach, intestines, kidneys, heart, brain, and placenta also make hormones.

Click here to take an online quiz on the location of the endocrine glands
The Pituitary Gland

The pituitary gland is often called the master gland. That is because the pituitary gland produces hormones that regulate other endocrine glands. Some hormones produced by the pituitary gland are:
1. Follicle Stimulating Hormone (FSH): Will be discussed in a later Chapter of the syllabus.
2. Luteinising Hormone (LH): Will be discussed in a later Chapter of the syllabus.
3. Growth Hormone (GH): Causes body cells to absorb amino acids and form protein for growth. The main function is to cause the elongation of bones.
4. Prolactin: stimulates milk formation by the breast after the birth of the baby.
5. Oxytocin: stimulates muscle contraction of uterus during birth, stimulates muscle contraction in the milk ducts during breast-feeding.
6. Antidiuretic Hormone (ADH): causes increased water reabsorption by kidneys.
7. Thyroid Stimulating Hormone (TSH): Combines with iodine at the thyroid gland to produce thyroxine.
Overproduction of GH causes gigantism and underproduction causes dwarfism.
The Hypothalamus

The hypothalamus links the nervous system with the endocrine system. It produces hormones that control the pituitary gland’s responses to messages from the brain and other hormones. Some these hormones, called releasing hormones, stimulate the pituitary gland to make other hormones. Others, called release inhibiting hormones, prevent the production of pituitary hormones.
An example is growth hormone releasing factor. This causes the production of growth hormone (GH) by the pituitary gland.
The Pineal Gland

This gland is in the brain. One hormone produced there is melatonin. Synthesis and release of melatonin is stimulated by darkness and inhibited by light. But even without visual cues, the level of melatonin in the blood rises and falls on a daily (circadian) cycle with peak levels occurring in the wee hours of the morning. Melatonin is readily available in drug stores and health food stores, and it has become quite popular. Ingesting even modest doses of melatonin raises the melatonin level in the blood to as much as 100 times greater than normal. These levels appear to promote going to sleep and thus help, insomnia to hasten recovery from jet lag, and to not to have dangerous side effects.
The Thyroid Gland

The thyroid gland produces the hormone called thyroxin. Thyroxin controls the rate of all the body’s internal reactions. In other words, thyroxin controls the rate of the body’s metabolism.
Physical conditions related to abnormal thyroid function are:
Hypothyroidism- Under Production of Thyroxine
1. Cretinism– Under production of thyroxin in young children. This results in low metabolic rates and results in retarded physical and mental development.
2. Myxoedema- Under production of thyroxin in adults. Characteristics are tiredness, lack of energy, slow mental and physical activity, and weight gain.
3. Goitre- Swelling of the thyroid caused by myxoedema.
Goitre
In cases of low production of thyroxine tablets are available to increase the thyroxine in the body. Since thyroxine needs iodine to be produced iodine is also administered to boost thyroxine levels.
Thyroxine Excess (Hyperthyroidism)
Thyroxine secretion is above normal. This causes a raised level of metabolism. Symptoms of over production of thyroxin are bulging eyes, weight loss heat production, nervousness, irritability, and anxiety. This condition is called Grave’s Disease. Corrective measures for Grave’s Disease are:
1. Drugs to suppress thyroid activity
2. Surgically remove part of the gland
3. Use radioactive iodine to destroy some of the gland.
The Parathyroids

There are 4 parathyroid glands. They are located within the thyroid gland. The hormone they produce is called parathormone. This hormone stimulates the release of calcium from the bones. That is why we must continue to include calcium in our diet even when our bones are fully grown.
The Thymus Gland

This gland is located behind the breastbone. It produces the hormone thymosin. This hormone causes white blood cells (lymphocytes) to become mature and active. These blood cells, as previously discussed in the Blood web page, are involved in the body’s immune system.
The Adrenal Glands
Click here to view an animation of the adrenal glands

The adrenal glands are located on top of each kidney. They secrete the hormone called adrenaline (also called epinephrine). This hormone prepares the body for stress and is released when we are frightened or feel stress. It does the following:
1. Increases blood flow to the heart, muscles, and brain.
2. Reduces blood flow to the kidneys. This helps reduce blood loss if we are cut. It causes us to get pale.
3. Opens the bronchioles allowing us to get more air.
4. Increases glucose levels in the blood.
5. Increases heartbeat rate.
6. Increase muscular contraction and strength.
7. Increases mental alertness.
Pancreas

As discussed in the Human Nutrition web page the pancreas secretes pancreatic juice for the digestive system.
In addition, the pancreas produces the hormone called insulin. This hormone is produced in groups of cells called Islets of Langerhans.
Insulin is needed because it reduces blood glucose levels in the blood. It causes cells, especially fat and muscle cells, to absorb glucose from the blood. The glucose is needed for cellular respiration or converted into glycogen. The glycogen is stored in the liver or the muscles for future use in cellular respiration.
Diabetes is a serious condition that results from 1 of 2 causes. In type 1 diabetes, the pancreas no longer makes insulin and therefore blood glucose cannot enter the cells to be used for energy. In type 2 diabetes, either the pancreas does not make enough insulin or the body is unable to use insulin correctly. Symptoms of diabetes are high glucose levels in the blood and urine, the production of large amounts of urine, severe thirst, loss of weight, and tiredness.
Injections of insulin, which are taken daily, the control of carbohydrate intake, exercise, and weight control treat diabetes.
Anabolic Steroids
Anabolic steroids are hormone supplements that habe been used. They build up muscle, speed up recovery of muscle from injury, and help strengthen bones. There are many serious side effects such as liver and adrenal gland failure, infertility, impotence, and the development of male characteristics in females that can result if they are misused. They are also, sometimes given to animals to promote increased lean muscle (meat) production. This practice is banned in the EU.
Control of Thyroxine Level
Control of thyroxine level as well as many other hormones is done by negative feedback. If the thyroxine level is normal the pituitary gland is inhibited from releasing thyroid stimulating hormone (TSH). As a result, no further thyroxine is produced. When thyroxine levels are low the pituitary gland produces TSH. This causes more thyroxine to be produced by the thyroid gland.

An Example of negative feedback in the role of the thyroid in maintaining body temperature at 37°C.:
OR:
| Where the Hormone is Produced | Hormone(s) Secreted | Hormone Function |
| Adrenal Glands | Adrenalin | Causes Emergency Responses (fight/flight) |
| Pituitary Gland | Growth hormone | Affects growth and development; stimulates protein production |
| Pancreas | Insulin | Lowers blood sugar levels; stimulates metabolism of glucose, protein, and fat |
Hypothalamus |
Growth Hormone Releasing Factor | Causes growth hormone to be made |
| Pineal Gland | Melatonin | Controls body rhythms |
| Parathyroid Glands | Parathyroid hormone (Parathormone) | Affects bone formation and excretion of calcium and phosphorus |
| Thyroid | Thyroxine | Controls Metabolism |
| Thymus | Thymosin | Matures white blood cells |
| Cow Eye Dissection |
Introduction:
How do we see? The eye processes the light through photoreceptors located in the eye that send signals to the brain and tells us what we are seeing. There are two types of photoreceptors, rods and cones. These photoreceptors are sensitive to the light. Rods are the most sensitive to light and therefore provide gray vision at night. Cones are mainly active in bright light and enable you to see color. There are 100 million rods compared to the 3 million cones located in your retina. The photoreceptors help you adjust to night and day. For example, if you walk inside from the sun, you can not initially see anything. This is due to the activity of the cones and the lack of activity of the rods. The rods become activated and adapted to the dim light, resulting in gray images formed in the dark. The same thing happens when you leave a dark movie theatre during the day. The rods are mainly activated and the cones have to adjust to sunlight when you leave the theatre.
Objective:
By dissecting the eye of a cow, which is similar to the eyes of all mammals including humans, you will gain an understanding of the structure and function of the parts of the eye.
Materials:
Cow eye, dissecting pan, dissecting kit, safety glasses, lab apron, and gloves
Procedure (External Structure):
Click here for labeled eye model
Procedure (Internal Structure):
10. Answer the worksheet questions on the cow eye dissection.
Click here for eye dissection questions
| BACK |
| Bacteria Worksheet | ![]() |
Bacterial Cell Evolution
1. Bacteria are microscopic _____________.
2. Fossils evidence shows bacteria are about __________ years old, while eukaryotes are about __________ years old.
3. Discuss where bacteria can be found.
4. Ribosomal differences have put bacteria into what two kingdoms? Which is the older group?
5. What is absent in the cell wall of Archaebacteria? Describe this substance.
6. Describe the environments in which you would find Archaebacteria.
7. Compare & contrast these tree groups of Archaebacteria — methanogens, extreme halophiles, and thermoacidophiles.
8. Most bacteria are found in what kingdom?
9. Name & describe the three shapes of Eubacteria.
10. Are Eubacteria aerobic or anaerobic? Explain.
11. Eubacteria may be heterotrophic or photosynthetic. Explain what this means & give an example of each type.
12. What type of staining is used to group Eubacteria?
13. Describe the appearance of gram-positive and gram-negative bacteria under a microscope.
14. Explain why Eubacteria do not all stain the same color during Gram staining.
15. Describe, in detail, cyanobacteria.
16. Cyanobacteria, also known as ______________ bacteria lack a membrane bound __________ & _____________.
17. How are heterocysts helpful to cyanobacteria?
18. What is eutrophication?
19. Explain the role of cyanobacteria in eutrophication.
20. What bacterium causes syphilis? Describe this bacteria.
21. Streptococci bacteria causing strep throat are in what group?
22. Why are actinomycete bacteria important?
23. Compare & contrast these three groups of Proteobacteria — enteric bacteria, chemoautotrophs, and nitrogen-fixing bacteria.
24.Name a genus of nitrogen-fixing bacteria found on the roots of soybeans in our area.
Characteristics of Bacteria
25. Name the three main parts of all bacteria.
26. Describe the cell wall of bacteria. How does this differ from a plant cell wall?
27. Compare & contrast the cell membrane of Eubacteria with that of other eukaryotes.
28.Are Gram positive or negative bacteria more protected against antibiotics & why?
29. Where does cell respiration take place in eukaryotes? in bacteria?
30. Describe how the cell membrane of photosynthetic bacteria are adapted for this process. Where does this process take place in plants?
31. Compare & contrast the cytoplasm of bacteria with that of eukaryotes.
32. Describe the DNA (hereditary material) found in bacteria. Make a sketch of what you think this would look like.
33. Where is the capsule of a bacteria, what is it made of, and give two ways it helps a bacterium?
34. Where is the glycoclayx of a bacteria, what is it made of, and how does it help a bacterium?
35. How do pili help the bacteria that have them?
36. How do Gram positive bacteria protect themselves against harsh environments?
37. Describe two methods of locomotion in bacteria.
38. Compare & contrast saprophytic and photoautotrophic bacterial nutrition.
39. Distinguish among these three bacteria & give an example of each — obligate anaerobes, facultative anaerobes, & obligate aerobes.
40. Compare & contrast these three methods of bacterial reproduction — transformation, conjugation, and transduction.
Bacteria and Humans
41. What does a pathologist do for a living?
42. Compare & contrast the two types of toxins bacteria produce.
43. Besides injuring the body by releasing toxins, how else do bacteria hurt the body?
44. Describe four antibiotics against bacteria.
45. Explain how antibiotic resistance occurs.
46. Name two bacterial diseases carried by ticks.
47. name two bacterial diseases caused by eating contaminated food.
48. Name a sexually transmitted bacterial disease.
49. Name a bacterium that can cause disease whenever it gets into deep wounds.
50. Name a bacterium that is transmitted by coughing & infects the lungs.
51. Describe, in detail, how bacteria can be useful to humans.