w3.salemstate.edu
www.windows.ucar.edu
What is sea floor spreading?
-->Sea-floor spreading is the process in which the ocean floor is extended when two plates move apart. As the plates move apart, the rocks break and form a crack between the plates. Earthquakes occur along the plate boundary. Magma rises through the cracks and seeps out onto the ocean floor like a long, thin, undersea volcano. library.thinkquest.org/17457/platetectonics/4.php
What are some of the major land forms that are created from plate movement?
-->A long chain of mountains forms gradually on the ocean floor as magma piles up along the crack. This chain is called an oceanic ridge. library.thinkquest.org/17457/platetectonics/4.php
How were the Mariana Islands formed?
-->A theory known as plate tectonics presumes that the Asian continent and the North and South American continents are moving and that the Lithosphere (crust) of the continents are composed of different material. The edge of these plates are believed to be moving in such a manner that one moves under the other and the cataclysmic forces that result push material upward to form islands. www.cnmi-guide.com/history/formation
What evidence exists today that the plates are still moving and that the islands are ancient volcanoes?
-->Plate tectonics is a theory of geology that has been developed to explain the observed evidence for large scale motions of the Earth's lithosphere. That facts that the fitting together of the coasts of the continents on the opposite sides of the Atlantic Ocean, the similarity of geologic formations and fossils found on the opposite sides, a geologically active mid-ocean ridge running along the central Atlantic between the opposite coasts, bottom sediments that get thicker the farther one travels from the ridge, and rocks on the sea floor on one side of the ridge show magnetic bands that are mirror images of rocks found on the opposite side of the ridge. en.wikipedia.org/wiki/Plate_tectonics#Plate_tectonic_theory
What is an atoll?
-->An atoll is an island of coral that encircles a lagoon partially or completely. Darwin (an English Naturalist) reasoned that a fringing coral reef surrounding a volcanic island in the tropical sea will grow upwards as the island subsides, becoming an "almost atoll" (barrier reef island). The fringing reef becomes a barrier reef for the reason that the outer part of the reef maintains itself near sea level through biotic growth, while the inner part of the reef falls behind, becoming a lagoon because conditions are less favorable for the corals and calcareous algae responsible for most reef growth. In time, subsidence carries the old volcano below the ocean surface, but the barrier reef remains. At this point, the island has become an atoll. http://en.wikipedia.org/wiki/Atoll
en.wikipedia.orgwikiAtoll
Why are atolls mainly found on the Pacific?-->Atolls are the product of the growth of tropical marine organisms, so these islands are only found in warm tropical waters. Volcanic islands located beyond the warm water temperature requirements of reef building organisms become seamounts as they subside and are eroded away at the surface. An island that is located where the ocean water temperatures are just sufficiently warm for upward reef growth to keep pace with the rate of subsidence is said to be at the Darwin Point.http://en.wikipedia.org/wiki/Atoll
Tuesday, December 11, 2007
Coral Reefs Part 1
As coral reefs are built, they go through different stages of growth. Throughout development, coral reefs characteristically sink into the water. Each of the following three stages describes a step the reef goes through while it sinks.
~Fringing Reefs~-->The fringing reef is the 1st stage of coral growth, being close to the island. When larvae is attached to sublittoral hard bottom and as corals grow, a fringing reef is formed along the coast. It can be found around the Caribbean Sea. Fringing reefs are close to shore so the water in which they live in gets run off and a mixture of nutrients and pollution from the land.
~Barrier Reefs~
-->Barrier reefs are the 2nd stage in coral reef development where the island has begun to sink. Corals then grow upwards and a lagoon will separate the barrier reef from land. They can be found around Australia, such as the Great Barrier Reef. They are farther out so they have access to water from the lagoon and the deeper ocean.
~Atolls~ -->Atolls are the last geological stage of sinking volcanic island. They are circles of corals with a lagoon in the center. In this stage, island has been completely been submersed in water. Its submersion explains why there is a lagoon in the center. Hundreds of atolls are speckled across the South Pacific.
The sun is the source of energy for the coral reef ecosystem. Plant plankton, called phytoplankton; algae; and other plants convert light energy into chemical energy through photosynthesis. As animals eat the plants and other animals, energy is passed on through the food chain. Reef building corals work together with microscopic algae, called zooxanthellae, that lives in their tissue. The zooxanthellae provide oxygen and food to the coral through photosynthesis. The coral polyp gives the algae a home, and the carbon dioxide it needs through respiration. Besides zooxanthellae, algae and seagrasses are the main types of plants in the coral reef ecosystem. These plants give food and oxygen to the animals that live on the reef. Seagrasses are especially important because they provide shelter for juvenile reef animals like conch and lobster.Coral reefs only make up about 1% of the ocean floor, but they house nearly 25% of life in the ocean. Animals use coral reefs either as a stopping point, like an oasis, as they travel the deep blue sea, or they live as residents at the reef. The corals themselves are the most abundant animal on the reef. They are tiny organisms are called polyps, that attach themselves to the hard reef and live there forever. The reef is like a giant apartment building in New York City and the coral polyps live together in each apartment. Corals are closely related to sea anemones and sea jellies, and use their tentacles for defense and to capture their prey. Corals can be a variety of colors, white, red, pink, green, blue, orange and purple, due to natural pigments and the zooxanthellae in their tissues.Other animals that live on the coral reef include sea urchins, sponges, sea stars, worms, fish, sharks, rays, lobster, shrimp, octopus, snails and many more. Many of these animals work together as a team like the coral polyp and zooxanthellae. This teamwork is called symbiosis. One example of symbiosis on the reef is the anemonefish and sea anemone. The sea anemone’s tentacles provide protection and safety for the fish and their eggs, while the fish protects the anemone from predators, such as butterflyfish. Sometimes anemonefish even remove parasites from their home anemone. http://www.jochemnet.de/fiu/OCB3043_39.htmlhttp://library.thinkquest.org/25713/reef_types.html#fringinghttp://www.nceas.ucsb.edu/nceas-web/kids/biomes/coral.htm
~Fringing Reefs~-->The fringing reef is the 1st stage of coral growth, being close to the island. When larvae is attached to sublittoral hard bottom and as corals grow, a fringing reef is formed along the coast. It can be found around the Caribbean Sea. Fringing reefs are close to shore so the water in which they live in gets run off and a mixture of nutrients and pollution from the land.
~Barrier Reefs~
-->Barrier reefs are the 2nd stage in coral reef development where the island has begun to sink. Corals then grow upwards and a lagoon will separate the barrier reef from land. They can be found around Australia, such as the Great Barrier Reef. They are farther out so they have access to water from the lagoon and the deeper ocean.
~Atolls~ -->Atolls are the last geological stage of sinking volcanic island. They are circles of corals with a lagoon in the center. In this stage, island has been completely been submersed in water. Its submersion explains why there is a lagoon in the center. Hundreds of atolls are speckled across the South Pacific.
The sun is the source of energy for the coral reef ecosystem. Plant plankton, called phytoplankton; algae; and other plants convert light energy into chemical energy through photosynthesis. As animals eat the plants and other animals, energy is passed on through the food chain. Reef building corals work together with microscopic algae, called zooxanthellae, that lives in their tissue. The zooxanthellae provide oxygen and food to the coral through photosynthesis. The coral polyp gives the algae a home, and the carbon dioxide it needs through respiration. Besides zooxanthellae, algae and seagrasses are the main types of plants in the coral reef ecosystem. These plants give food and oxygen to the animals that live on the reef. Seagrasses are especially important because they provide shelter for juvenile reef animals like conch and lobster.Coral reefs only make up about 1% of the ocean floor, but they house nearly 25% of life in the ocean. Animals use coral reefs either as a stopping point, like an oasis, as they travel the deep blue sea, or they live as residents at the reef. The corals themselves are the most abundant animal on the reef. They are tiny organisms are called polyps, that attach themselves to the hard reef and live there forever. The reef is like a giant apartment building in New York City and the coral polyps live together in each apartment. Corals are closely related to sea anemones and sea jellies, and use their tentacles for defense and to capture their prey. Corals can be a variety of colors, white, red, pink, green, blue, orange and purple, due to natural pigments and the zooxanthellae in their tissues.Other animals that live on the coral reef include sea urchins, sponges, sea stars, worms, fish, sharks, rays, lobster, shrimp, octopus, snails and many more. Many of these animals work together as a team like the coral polyp and zooxanthellae. This teamwork is called symbiosis. One example of symbiosis on the reef is the anemonefish and sea anemone. The sea anemone’s tentacles provide protection and safety for the fish and their eggs, while the fish protects the anemone from predators, such as butterflyfish. Sometimes anemonefish even remove parasites from their home anemone. http://www.jochemnet.de/fiu/OCB3043_39.htmlhttp://library.thinkquest.org/25713/reef_types.html#fringinghttp://www.nceas.ucsb.edu/nceas-web/kids/biomes/coral.htm
Tuesday, December 4, 2007
Corals Reef Part 2
--The southern coast of Saipan contains several beautiful beaches where extensive reef development has occurred through time. The CNMI Monitoring Program conducts surveys on the reefs adjacent to Obyan, Boyscout, and Coral Ocean Point beaches. These reefs are fortunate for their favorable environmental setting consisting of; 1) protection from prevailing NE swells (low exposure), and 2) adjacent, small watersheds consisting of raised limestone rock, with relatively low amounts of terrigenous sediments washing into the marine environment during storms. These environmental conditions have led to the development of lush, three-dimensional reef structures that exist today. The living reef (the top few centimeters of the reef structure) has been exposed to various natural disturbances over the years. These include large crown-of-thorns starfish populations (COTS) (1969, 1985, 1995, 2004-6) and frequent typhoons.we believe the reef to be resilient based upon the relatively high levels of coralline algae, which are the preferred substrate for new coral settlement, and large number of new coral recruits.
-->Lau Lau Bay contains some of the most diverse yet threatened reefs in the entire CNMI. The protected nature of the bay has allowed thriving reefs to development over the past 5,000 years, resulting in amazing, three dimensional reef structure today. This reef structure is valued by divers and fishermen alike because of its beauty and fish habitat that it provides. The protection and isolation of the bay also means that these reefs are more susceptible to disturbances (typhoons and pollution).
http://www.cnmicoralreef.net/ns/laulau2.html
Wednesday, November 7, 2007
Virtual Lab Dissections
~Crayfish~
http://universe-review.ca/I10-82-crayfish.jpg
a.) Digestive System: The digestive tract consists of the foregut, which includes an enlarged stomach, part of which is specialized for grinding; the midgut, which extends from the foregut; and the hindgut, which leads to the anus and functions in water and salt regulation (Miller and Harley, 1992; Snodgrass,1965). The digestive gland secretes digestive enzymes and aids in the absorption of the products of digestion (Pennak, 1989). http://www.science.mcmaster.ca/Biology/Harbour/SPECIES/CRAYFISH/CRAYFISH.HTM#Digestiveb.) Circulatory System: The circlatory system of the crayfish is centred around a muscular heart with dorsal, anterior, and posterior arteries leading away from it . Branches of these vessels empty into the sinuses of the hemocoel (the large tissue spaces containing blood). The ventral sinus collects the blood, the blood travels through the gills, and then returns to the pericardial sinus surrounding ther heart (Miller and Hurley, 1992; Snodgrass, 1965). http://www.science.mcmaster.ca/Biology/Harbour/SPECIES/CRAYFISH/CRAYFISH.HTM#Digestivec.) Nervous System: The crayfish nervous system is composed of a ventral nerve cord fused with segmental ganglia, and the supresophageal and subesophageal ganglia (Miller and Harley, 1992). Giant neurons in the ventral nerve cord function in escape responses (Bliss, 1990). The supraesophageal and subesophageal ganglia control the head appendages in response to sesory input recieved from receptors (Miller and Harley, 1992). http://www.science.mcmaster.ca/Biology/Harbour/SPECIES/CRAYFISH/CRAYFISH.HTM#Digestived.) Excretory System: The excretory organs are also called the antennal glands because they are located at the base of the second antenna. They exrete the waste products of blood filtration; ammonia is the primary waste product (Miller and Harley, 1992). Ammonia is also excreted across the gill surfaces and by diffusion across thin parts of the exoskeleton (Snodgrass, 1965) http://www.science.mcmaster.ca/Biology/Harbour/SPECIES/CRAYFISH/CRAYFISH.HTM#Digestivee.) Reproductive System: Crayfish have separate male and female sexes (dioecious) and the gonads are located in the dorsal portion of the thorax (Miller and Harley, 1992). Mating occurs just after the female has molted, usually in the spring. The male deposits sperm near the openings of the female gonoducts (at the base of the 3rd periopods) and uses the two modified pleopods to guide the sperm into the female sperm receptacle. http://www.science.mcmaster.ca/Biology/Harbour/SPECIES/CRAYFISH/CRAYFISH.HTM#Digestivef.) Integumentary System: This crustacean has a hard exoskeleton that protects and supports the body. The crayfish has 8 jointed walking legs, a segmented body, 2 pairs of sensory antennae, and compound eyes. It has 2 large pincers or claws called chelipeds. If a crayfish loses a leg, the leg will regenerate (regrow). The head and thorax are fused, forming the cephalothorax. Using gills, a crayfish breathes oxygen that is dissolved in water. Juvenile crawfish are light tan, but adults are deep red. http://www.enchantedlearning.com/subjects/invertebrates/crustacean/Crayfishprintout.shtmlg.) Body Plan: The body of the crayfish is divided into two regions: the cephalothorax, which has sensory, feeding, and locomotor functions; and the abdomen, which has locomotor and visceral functions (Miller and Harley, 1992) http://www.science.mcmaster.ca/Biology/Harbour/SPECIES/CRAYFISH/CRAYFISH.HTM#DigestiveDescription of its unique habitat, diet and what distinguishes it as a mollusk, echinoderm, or arthropod.--> Crayfish live in streams, rivers, swamps, ponds, and other freshwater habitats. Most crayfish are strictly aquatic but some live in semi-aquatic environments. The semi-aquatic crayfish burrow into the soil to get to water (so that they can breathe). Crayfish are omnivores; they eat plants, animals, and decaying organisms. They are nocturnal (most active at night) and eat fish, shrimp, water plants, worms, insects, snails, and plankton. Larval crayfish are very tiny; they eat plankton. Their color depends on diet. As a crayfish grows, it often molts (loses its old shell and grows a new one). It eats the old shell. http://www.enchantedlearning.com/subjects/invertebrates/crustacean/Crayfishprintout.shtml
~Clam~
http://kentsimmons.uwinnipeg.ca/16cm05/1116/33-21-ClamAnatomy-L.jpg
a.) Digestive System: A clam has food brought in through a siphon system and then to its mouth. It then goes to a digstive gland and to its intestine. Wastes via the anus.
b.) Circulatory System: A clam has a heart, blood, and blood vessels.
c.) Nervous System: A clam has no formal nervous system, but has a series of ganglia that conduct impulses.
d.) Excretory System: A clam has an excretory system with an anus. It has an organ called the nephridium that gets rid of wastes.
e.) Reproductive System: A clam is either male or female and reproduces sexually with a large organ called a gonad.
f.) Integumentary System: A Mollusk has a soft, thick, fleshy body. It can be very small or as big as six feet across.
g.) Body Plan: A clam has a soft, thick, fleshy body. It can be very small or as big as six feet across.Description of its unique habitat, diet and what distinguishes it as a mollusk, echinoderm, or arthropod.
http://www.mcwdn.org/Animals/Mollusks.html
~Starfish~
http://www.esu.edu/~milewski/intro_biol_two/lab__13_echinoderm/images/aster_diagr_organs.jpg
a.) Digestive System: Starfish digestion is carried out in two stomachs: the cardiac stomach and the pyloric stomach. The cardiac stomach, which is a sack like stomach located at the center of the body may be everted—pushed out of the organism's body and used to engulf and digest food. Some species take advantage of the endurance of their water vascular systems to force open the shells of bivalve mollusks such as clams and mussels by injecting their stomachs into the shells. With the stomach inserted inside the shell, it digests the mollusk in place. The cardiac stomach is then brought back inside the body, and the partially digested food is moved to the pyloric stomach. Further digestion occurs in the intestine and waste is either excreted through the anus on the aboral side of the body, or if the anus is absent (as in brittle stars), waste is excreted through the mouth. http://en.wikipedia.org/wiki/Starfish#Digestion_and_excretion
b.) Circulatory System: Circulation occurs in three places: the perivisceral coelom (basically, the space inside the body but outside the various organs), the water vascular system (of which the tube feet are the most obvious part), and the hemal system (which actually looks something like a circulatory system). The hemal system is shown below. There are hemal channels forming rings around the central part of the body around the mouth (the oral hemal ring), closer to the upper surface (the aboral hemal ring), and a third ring around the digestive system (the gastric hemal ring). These are connected by the axial sinus. There are also radial hemal channels running down the rays next to the gonads (which are also located in the rays). A dorsal sac attached to the axial sinus pulsates, sort of like a very inefficient heart (inefficient because it lacks a one-way valve system). The hemal system seems mostly organized to distribute nutrients from the digestive tract.
http://www.vsf.cape.com/%7Ejdale/science/digest.htm
c.) Nervous System: Echinoderms have rather complex nervous systems, but lack a true centralized brain. All echinoderms have a nerve plexus (a network of interlacing nerves), which lies within as well as below the skin. The esophagus is also surrounded by a number of nerve rings, which send radial nerves that are often parallel with the branches of the water vascular system. The ring nerves and radial nerves coordinate the starfish's balance and directional systems. Although the echinoderms do not have many well-defined sensory inputs, they are sensitive to touch, light, temperature, orientation, and the status of water around them. The tube feet, spines, and pedicellariae found on starfish are sensitive to touch, while eyespots on the ends of the rays are light-sensitive. http://en.wikipedia.org/wiki/Starfish#Digestion_and_excretion
d.) Excretory System: None.
e.) Reproductive System: Starfish are capable of both sexual and asexual reproduction. Individual starfish are male or female. Fertilization takes place externally, both male and female releasing their gametes into the environment. Resulting fertilized embryos form part of the zooplankton. Some species of starfish also reproduce asexually by fragmentation, often with part of an arm becoming detached and eventually developing into an independent individual starfish. http://en.wikipedia.org/wiki/Starfish#Digestion_and_excretion
f.) Integumentary System: (structure ie skin, exoskeleton, shell, etc.)
g.) Body Plan: Most starfish have five arms, however some have more or fewer; in fact some starfish can have different numbers of arms even within one species. The mouth is located underneath the starfish on the oral or ventral surface, while the anus is located on the top of the animal. The spiny upper surface covering the species is called the aboral or dorsal surface. On the aboral surface there is a structure called the madreporite, a small white spot located slightly off-center on the central disc which acts as a water filter and supplies the starfish's water vascular system with water to move. http://en.wikipedia.org/wiki/Starfish#Digestion_and_excretion
Description of its unique habitat, diet and what distinguishes it as a mollusk, echinoderm, or arthropod.
~Squid~
http://www.utmb.edu/nrcc/UFAW%20squid.jpg
a.) Digestive System: Squid, like all cephalopods, have complex digestive systems. Food is transported into a muscular stomach, found roughly in the midpoint of the visceral mass. The bolus is then transported into the caecum for digestion. The caecum, a long, white organ, is found next to the ovary or testis. In mature squid, more priority is given to reproduction and so the stomach and caecum often shrivel up during the later stages of life. Finally, food goes to the liver (or digestive gland), found at the siphon end of the squid, for absorption. Solid waste is passed out of the rectum. Beside the rectum is the ink sac, which allows a squid to discharge a black ink into the mantle cavity at short notice.
http://en.wikipedia.org/wiki/Squid#Digestive_system
b.) Circulatory System: The circulatory system is open, except in Cephalopoda and usually includes a dorsal heart with one or two atrias and one ventricle. This is situated in a pericardial cavity. An anterior aorta and other vessels and many blood spaces (hemocoels) exist in the tissues.
http://marinebiology-shine.blogspot.com/2007_10_01_archive.html
c.) Nervous System: The giant axon of the squid, which may be up to 1 mm in diameter, innervates the mantle and controls part of the jet propulsion system.
http://en.wikipedia.org/wiki/Squid#Digestive_system
d.) Excretory System: Squid have three hearts. Two branchial hearts, feeding the gills, each surrounding the larger systemic heart that pumps blood around the body. The hearts have a faint greenish appearance and are surrounded by the renal sacs - the main excretory system of the squid. The kidneys are faint and difficult to identify and stretch from the hearts (located at the posterior side of the ink sac) to the liver. The systemic heart is made of three chambers, a lower ventricle and two upper auricles.
http://en.wikipedia.org/wiki/Squid#Digestive_system
e.) Reproductive System: In female squid, the ink sac is hidden from view by a pair of white nidamental glands, which lie anterior to the gills. There are also red-spotted accessory nidamental glands. Both of these organs are associated with manufacture of food supplies and shells for the eggs. Females also have a large translucent ovary, situated towards the posterior of the visceral mass.Male squid do not possess these organs, but instead have a large testis in place of the ovary, and a spermatophoric gland and sac. In mature males, this sac may contain spermatophores, which are placed inside the mantle of the female during mating.
http://en.wikipedia.org/wiki/Squid#Digestive_system
f.) Integumentary System: The integumentary system of a squid is enclosed in the mantle, which has two swimming fins along each side. These fins are not the main source of their motility. The skin of the squid is covered in chromatophores, which allows the squid to change color to suit its environment. The underside of the squid is also found to be lighter than the topside, in order to provide camouflage from both prey and predator (countershading).Under the body are openings to the mantle cavity, which contains the gill and openings to the excretory and reproductive systems. At the front of the mantle cavity lies the siphon, which the squid uses for locomotion through means of jet propulsion. This is done by sucking water into the mantle cavity and quickly expelling it out of the siphon in a fast, strong jet. The direction of the siphon can be changed in order to suit the direction of travel.Inside the mantle cavity, beyond the siphon, lies the visceral mass of the squid, which is covered in a thin skin. Under this are all the major internal organs of the squid.
http://taylorsinsight.blogspot.com/
g.) Body Plan: Like all cephalopods, squid are distinguished by having a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms and two tentacles arranged in pairs.
http://en.wikipedia.org/wiki/Squid#Digestive_system
Description of its unique habitat, diet and what distinguishes it as a mollusk, echinoderm, or arthropod.
-->Squids live in the ocean - a few, most notably the giant squid and the colossal squid live out in the colder open ocean. Many of the smaller species of squid rely on color changing patterns in order to communicate with each other and to attract prey as well. Squids are considered to be one of the most successful and highly complex of all invertebrates.
http://taylorsinsight.blogspot.com/
http://universe-review.ca/I10-82-crayfish.jpg
a.) Digestive System: The digestive tract consists of the foregut, which includes an enlarged stomach, part of which is specialized for grinding; the midgut, which extends from the foregut; and the hindgut, which leads to the anus and functions in water and salt regulation (Miller and Harley, 1992; Snodgrass,1965). The digestive gland secretes digestive enzymes and aids in the absorption of the products of digestion (Pennak, 1989). http://www.science.mcmaster.ca/Biology/Harbour/SPECIES/CRAYFISH/CRAYFISH.HTM#Digestiveb.) Circulatory System: The circlatory system of the crayfish is centred around a muscular heart with dorsal, anterior, and posterior arteries leading away from it . Branches of these vessels empty into the sinuses of the hemocoel (the large tissue spaces containing blood). The ventral sinus collects the blood, the blood travels through the gills, and then returns to the pericardial sinus surrounding ther heart (Miller and Hurley, 1992; Snodgrass, 1965). http://www.science.mcmaster.ca/Biology/Harbour/SPECIES/CRAYFISH/CRAYFISH.HTM#Digestivec.) Nervous System: The crayfish nervous system is composed of a ventral nerve cord fused with segmental ganglia, and the supresophageal and subesophageal ganglia (Miller and Harley, 1992). Giant neurons in the ventral nerve cord function in escape responses (Bliss, 1990). The supraesophageal and subesophageal ganglia control the head appendages in response to sesory input recieved from receptors (Miller and Harley, 1992). http://www.science.mcmaster.ca/Biology/Harbour/SPECIES/CRAYFISH/CRAYFISH.HTM#Digestived.) Excretory System: The excretory organs are also called the antennal glands because they are located at the base of the second antenna. They exrete the waste products of blood filtration; ammonia is the primary waste product (Miller and Harley, 1992). Ammonia is also excreted across the gill surfaces and by diffusion across thin parts of the exoskeleton (Snodgrass, 1965) http://www.science.mcmaster.ca/Biology/Harbour/SPECIES/CRAYFISH/CRAYFISH.HTM#Digestivee.) Reproductive System: Crayfish have separate male and female sexes (dioecious) and the gonads are located in the dorsal portion of the thorax (Miller and Harley, 1992). Mating occurs just after the female has molted, usually in the spring. The male deposits sperm near the openings of the female gonoducts (at the base of the 3rd periopods) and uses the two modified pleopods to guide the sperm into the female sperm receptacle. http://www.science.mcmaster.ca/Biology/Harbour/SPECIES/CRAYFISH/CRAYFISH.HTM#Digestivef.) Integumentary System: This crustacean has a hard exoskeleton that protects and supports the body. The crayfish has 8 jointed walking legs, a segmented body, 2 pairs of sensory antennae, and compound eyes. It has 2 large pincers or claws called chelipeds. If a crayfish loses a leg, the leg will regenerate (regrow). The head and thorax are fused, forming the cephalothorax. Using gills, a crayfish breathes oxygen that is dissolved in water. Juvenile crawfish are light tan, but adults are deep red. http://www.enchantedlearning.com/subjects/invertebrates/crustacean/Crayfishprintout.shtmlg.) Body Plan: The body of the crayfish is divided into two regions: the cephalothorax, which has sensory, feeding, and locomotor functions; and the abdomen, which has locomotor and visceral functions (Miller and Harley, 1992) http://www.science.mcmaster.ca/Biology/Harbour/SPECIES/CRAYFISH/CRAYFISH.HTM#DigestiveDescription of its unique habitat, diet and what distinguishes it as a mollusk, echinoderm, or arthropod.--> Crayfish live in streams, rivers, swamps, ponds, and other freshwater habitats. Most crayfish are strictly aquatic but some live in semi-aquatic environments. The semi-aquatic crayfish burrow into the soil to get to water (so that they can breathe). Crayfish are omnivores; they eat plants, animals, and decaying organisms. They are nocturnal (most active at night) and eat fish, shrimp, water plants, worms, insects, snails, and plankton. Larval crayfish are very tiny; they eat plankton. Their color depends on diet. As a crayfish grows, it often molts (loses its old shell and grows a new one). It eats the old shell. http://www.enchantedlearning.com/subjects/invertebrates/crustacean/Crayfishprintout.shtml
~Clam~
http://kentsimmons.uwinnipeg.ca/16cm05/1116/33-21-ClamAnatomy-L.jpg
a.) Digestive System: A clam has food brought in through a siphon system and then to its mouth. It then goes to a digstive gland and to its intestine. Wastes via the anus.
b.) Circulatory System: A clam has a heart, blood, and blood vessels.
c.) Nervous System: A clam has no formal nervous system, but has a series of ganglia that conduct impulses.
d.) Excretory System: A clam has an excretory system with an anus. It has an organ called the nephridium that gets rid of wastes.
e.) Reproductive System: A clam is either male or female and reproduces sexually with a large organ called a gonad.
f.) Integumentary System: A Mollusk has a soft, thick, fleshy body. It can be very small or as big as six feet across.
g.) Body Plan: A clam has a soft, thick, fleshy body. It can be very small or as big as six feet across.Description of its unique habitat, diet and what distinguishes it as a mollusk, echinoderm, or arthropod.
http://www.mcwdn.org/Animals/Mollusks.html
~Starfish~
http://www.esu.edu/~milewski/intro_biol_two/lab__13_echinoderm/images/aster_diagr_organs.jpg
a.) Digestive System: Starfish digestion is carried out in two stomachs: the cardiac stomach and the pyloric stomach. The cardiac stomach, which is a sack like stomach located at the center of the body may be everted—pushed out of the organism's body and used to engulf and digest food. Some species take advantage of the endurance of their water vascular systems to force open the shells of bivalve mollusks such as clams and mussels by injecting their stomachs into the shells. With the stomach inserted inside the shell, it digests the mollusk in place. The cardiac stomach is then brought back inside the body, and the partially digested food is moved to the pyloric stomach. Further digestion occurs in the intestine and waste is either excreted through the anus on the aboral side of the body, or if the anus is absent (as in brittle stars), waste is excreted through the mouth. http://en.wikipedia.org/wiki/Starfish#Digestion_and_excretion
b.) Circulatory System: Circulation occurs in three places: the perivisceral coelom (basically, the space inside the body but outside the various organs), the water vascular system (of which the tube feet are the most obvious part), and the hemal system (which actually looks something like a circulatory system). The hemal system is shown below. There are hemal channels forming rings around the central part of the body around the mouth (the oral hemal ring), closer to the upper surface (the aboral hemal ring), and a third ring around the digestive system (the gastric hemal ring). These are connected by the axial sinus. There are also radial hemal channels running down the rays next to the gonads (which are also located in the rays). A dorsal sac attached to the axial sinus pulsates, sort of like a very inefficient heart (inefficient because it lacks a one-way valve system). The hemal system seems mostly organized to distribute nutrients from the digestive tract.
http://www.vsf.cape.com/%7Ejdale/science/digest.htm
c.) Nervous System: Echinoderms have rather complex nervous systems, but lack a true centralized brain. All echinoderms have a nerve plexus (a network of interlacing nerves), which lies within as well as below the skin. The esophagus is also surrounded by a number of nerve rings, which send radial nerves that are often parallel with the branches of the water vascular system. The ring nerves and radial nerves coordinate the starfish's balance and directional systems. Although the echinoderms do not have many well-defined sensory inputs, they are sensitive to touch, light, temperature, orientation, and the status of water around them. The tube feet, spines, and pedicellariae found on starfish are sensitive to touch, while eyespots on the ends of the rays are light-sensitive. http://en.wikipedia.org/wiki/Starfish#Digestion_and_excretion
d.) Excretory System: None.
e.) Reproductive System: Starfish are capable of both sexual and asexual reproduction. Individual starfish are male or female. Fertilization takes place externally, both male and female releasing their gametes into the environment. Resulting fertilized embryos form part of the zooplankton. Some species of starfish also reproduce asexually by fragmentation, often with part of an arm becoming detached and eventually developing into an independent individual starfish. http://en.wikipedia.org/wiki/Starfish#Digestion_and_excretion
f.) Integumentary System: (structure ie skin, exoskeleton, shell, etc.)
g.) Body Plan: Most starfish have five arms, however some have more or fewer; in fact some starfish can have different numbers of arms even within one species. The mouth is located underneath the starfish on the oral or ventral surface, while the anus is located on the top of the animal. The spiny upper surface covering the species is called the aboral or dorsal surface. On the aboral surface there is a structure called the madreporite, a small white spot located slightly off-center on the central disc which acts as a water filter and supplies the starfish's water vascular system with water to move. http://en.wikipedia.org/wiki/Starfish#Digestion_and_excretion
Description of its unique habitat, diet and what distinguishes it as a mollusk, echinoderm, or arthropod.
~Squid~
http://www.utmb.edu/nrcc/UFAW%20squid.jpg
a.) Digestive System: Squid, like all cephalopods, have complex digestive systems. Food is transported into a muscular stomach, found roughly in the midpoint of the visceral mass. The bolus is then transported into the caecum for digestion. The caecum, a long, white organ, is found next to the ovary or testis. In mature squid, more priority is given to reproduction and so the stomach and caecum often shrivel up during the later stages of life. Finally, food goes to the liver (or digestive gland), found at the siphon end of the squid, for absorption. Solid waste is passed out of the rectum. Beside the rectum is the ink sac, which allows a squid to discharge a black ink into the mantle cavity at short notice.
http://en.wikipedia.org/wiki/Squid#Digestive_system
b.) Circulatory System: The circulatory system is open, except in Cephalopoda and usually includes a dorsal heart with one or two atrias and one ventricle. This is situated in a pericardial cavity. An anterior aorta and other vessels and many blood spaces (hemocoels) exist in the tissues.
http://marinebiology-shine.blogspot.com/2007_10_01_archive.html
c.) Nervous System: The giant axon of the squid, which may be up to 1 mm in diameter, innervates the mantle and controls part of the jet propulsion system.
http://en.wikipedia.org/wiki/Squid#Digestive_system
d.) Excretory System: Squid have three hearts. Two branchial hearts, feeding the gills, each surrounding the larger systemic heart that pumps blood around the body. The hearts have a faint greenish appearance and are surrounded by the renal sacs - the main excretory system of the squid. The kidneys are faint and difficult to identify and stretch from the hearts (located at the posterior side of the ink sac) to the liver. The systemic heart is made of three chambers, a lower ventricle and two upper auricles.
http://en.wikipedia.org/wiki/Squid#Digestive_system
e.) Reproductive System: In female squid, the ink sac is hidden from view by a pair of white nidamental glands, which lie anterior to the gills. There are also red-spotted accessory nidamental glands. Both of these organs are associated with manufacture of food supplies and shells for the eggs. Females also have a large translucent ovary, situated towards the posterior of the visceral mass.Male squid do not possess these organs, but instead have a large testis in place of the ovary, and a spermatophoric gland and sac. In mature males, this sac may contain spermatophores, which are placed inside the mantle of the female during mating.
http://en.wikipedia.org/wiki/Squid#Digestive_system
f.) Integumentary System: The integumentary system of a squid is enclosed in the mantle, which has two swimming fins along each side. These fins are not the main source of their motility. The skin of the squid is covered in chromatophores, which allows the squid to change color to suit its environment. The underside of the squid is also found to be lighter than the topside, in order to provide camouflage from both prey and predator (countershading).Under the body are openings to the mantle cavity, which contains the gill and openings to the excretory and reproductive systems. At the front of the mantle cavity lies the siphon, which the squid uses for locomotion through means of jet propulsion. This is done by sucking water into the mantle cavity and quickly expelling it out of the siphon in a fast, strong jet. The direction of the siphon can be changed in order to suit the direction of travel.Inside the mantle cavity, beyond the siphon, lies the visceral mass of the squid, which is covered in a thin skin. Under this are all the major internal organs of the squid.
http://taylorsinsight.blogspot.com/
g.) Body Plan: Like all cephalopods, squid are distinguished by having a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms and two tentacles arranged in pairs.
http://en.wikipedia.org/wiki/Squid#Digestive_system
Description of its unique habitat, diet and what distinguishes it as a mollusk, echinoderm, or arthropod.
-->Squids live in the ocean - a few, most notably the giant squid and the colossal squid live out in the colder open ocean. Many of the smaller species of squid rely on color changing patterns in order to communicate with each other and to attract prey as well. Squids are considered to be one of the most successful and highly complex of all invertebrates.
http://taylorsinsight.blogspot.com/
Wednesday, October 3, 2007
Genetics/ Cell Cycle Questions (currently under construction)
1. What is DNA?
DNA - the Blueprint of Life
Every living organism contains within itself the information it needs to build a new organism. This information, you could think of it as a blueprint of life, is stored in the organism's genome. The genome is made up of a material called DNA, which stands for deoxyribonucleic acid. If you take a really, really close look at the DNA molecule you will see that it looks like an ordinary ladder, although somewhat twisted. The steps that connects the two strands in this ladder are composed of four different molecules of the same type, called nucleotides. In DNA they are A, T, C and G; where A stands for adenine, T for thymine, C for cytosine and finally G for guanine.
2. What are the 4 bases?
The steps that connect the two strands in this ladder are composed of four different molecules of the same type, called nucleotides. In DNA they are A, T, C and G; where A stands for adenine, T for thymine, C for cytosine and finally G for guanine.
3. What 2 peices of information did the scientists need to solve the elusive structure of DNA?
In the late 1940's, the members of the scientific community were aware that DNA was most likely the molecule of life, even though many were skeptical since it was so "simple." They also knew that DNA included different amounts of the four bases adenine, thymine, guanine and cytosine (usually abbreviated A, T, G and C), but nobody had the slightest idea of what the molecule might look like.
In order to solve the elusive structure of DNA, a couple of distinct pieces of information needed to be put together. One was that the phosphate backbone was on the outside with bases on the inside; another that the molecule was a double helix. It was also important to figure out that the two strands run in opposite directions and that the molecule had a specific base pairing.
As in the solving of other complex problems, the work of many people was needed to establish the full picture.
4. What are the specific base pairs?
The four specific base pairs are adenine, thymine, & guanine, cytosine.
The base-pairing mystery had been partly solved by the biochemist Erwin Chargoff some years earlier. In 1949 he showed that even though different organisms have different amounts of DNA, the amount of adenine always equals the amount of thymine. The same goes for the pair guanine and cytosine. For example, human DNA contains about 30 percent each of adenine and thymine, and 20 percent each of guanine and cytosine.
With this information at hand Watson was able to figure out the pairing rules. On the 21st of February 1953 he had the key insight, when he saw that the adenine-thymine bond was exactly as long as the cytosine-guanine bond. If the bases were paired in this way, each rung of the twisted ladder in the helix would be of equal length, and the sugar-phosphate backbone would be smooth.
5. How does the pairing rule effect the shape and structure of DNA?
Each rung of the twisted ladder in the Helix would be of equal length, and the sugar- phosphate backbone would be smooth.
6. What does the DNA do during cell division?
It is able to “unzip” into two pairs.
7. How many base pairs does E. Coli have? How long does it take to replicate? How is the DNA packaged in the cell?
4 million, once every 20 minutes 3 million, Its is curled up in a condensed fashion.
8. How many base pairs does Human DNA have? How long does it take to replicate? How is the DNA packaged in the cell?
12-24 in 23 distinct chromosome pairs.
Cell Diffusion (currently under construction)
Using Word and Excel to publish your results answer the following questions and complete the following experiment.
What is diffusion?
* The movement of molecules from an area of high concentration to an area of low concentration.
What is osmosis?
* The movement of water across a selectively permeable membrane, such as the cell membrane, which allows only certain molecules to pass through.
Can you demonstrate these two processes using a gummy bear?
Write a hypothesis and a prediction.
Set up an experiment, identify your controls, variables and what you are going to measure.
List your steps, in a logical and specific order
Create a data table in Excel for your observations. Import this into Word. Convert the data table into a graph. Import this into Word as well.
Write an explanation of your results and conclusion. Use your data to support your explanation.
Upload your assignment.
What is diffusion?
* The movement of molecules from an area of high concentration to an area of low concentration.
What is osmosis?
* The movement of water across a selectively permeable membrane, such as the cell membrane, which allows only certain molecules to pass through.
Can you demonstrate these two processes using a gummy bear?
Write a hypothesis and a prediction.
Set up an experiment, identify your controls, variables and what you are going to measure.
List your steps, in a logical and specific order
Create a data table in Excel for your observations. Import this into Word. Convert the data table into a graph. Import this into Word as well.
Write an explanation of your results and conclusion. Use your data to support your explanation.
Upload your assignment.
Tuesday, October 2, 2007
Photosynthesis and Cellular Respiration
Photosynthesis is the process where green plants use sunlight, carbon dioxide, and water to make food and oxygen.Respiration is the process where cells use this food to release stored energy.
Photosynthesis: 6CO2 + 6H2O + energy --> 6O2 + C6H12O6
Cellular Respiration: 6O2 + C6H12O6 --> 6H2O + 6CO2 + energy
- Sunlight produces the energy source for Photosynthesis. It uses water and carbon dioxide to make glucose. Cellular Respiration is the opposite of Photosynthesis. It breaks down glucose, using oxygen which creates water and carbon dioxide.
Results are: O2+C6H12O6->H2O+ATP+CO2
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