Critical Thinking Questions: Mass Re-Collection Part 2

Critical Thinking

Chapter 7

1. Cephalopods, the squids, octopuses, and allies, show a much higher degree of structural and behavioral complexity then the other groups of molluscs. What factors triggered the evolution of these changes? A rich fossil record among cephalopods shows that once they were very common and even dominant in some marine environments. Now there are only about 650 living species of cephalopods, far fewer than gastropods. In the end, were cephalopods successful? What do you think happened along the way?

For any amount of evolutionary advancement to such a height in the structural and behavioral complexity of the cephalopods, would require millions of years and several processes of natural selection. My hypothesis on this evolutionary achievement would be either that they were, at one point, at a disadvantage and had to rely on other ways to either obtain food and/or to defend themselves against predators. Yet, in accordance to the fossil record, which in the question states that, “A rich fossil record among cephalopods shows that once they were very common and even dominant in some marine environments. Now there are only about 650 living species of cephalopods, far fewer than gastropods”, in that the several species of cephalopods may have died out due to the mass extinction several millions years ago, and that those that survived, may have more species die out because of the competition between one another for food; it is here where my hypothesis may come into play. But in terms of their success, it is both a negative and positive one, for in terms of their diversification, it is a negative because of the amount of species that are currently living today; yet, it is also a positive because of their structural and behavioral complexity that they have gained through the millions of years of natural selection.

Chapter 9

1. Sea turtles have disappeared from many regions, and one way of trying to save them is to reintroduce them to areas where they have been wiped out. This is done by reburying eggs or by releasing newborn baby turtles on beaches. Why are eggs reburied or baby turtles released instead of fully grown individuals?

According to several theories on how sea turtles find their birth place to lay eggs, though they spend majority of their lives hundreds of miles away from it, is due to the magnetic field that has imprinted itself in their brain during incubation and/or hatching. Therefore, it would be best that the eggs would be reburied instead of re-introducing adults to a new beach.

Chapter 18

1. Wastes from duck farms used to wash into two shallow-waters bays on Long Island, New York. The wastes, rich in nutrients such as nitrates and phosphate, polluted the water. What do you suppose was the immediate effect of the pollutants? Can you speculate on the likely effects on the commercially valuable shellfish of the area?

Because of the rich chemicals that contaminated the bay from the results of run-off, there will be two immediate consequences: 1. all the organisms sensitive to slight environmental changes will die quickly and the remaining surviving organisms will be forced to move, 2. those organisms that survive may go through the event of a population explosion where competitive exclusion takes place and later, because of the shortage in the amount of food consumed by the dominant organism, they may die and be forced to move as well.

The shellfish, being greatly affected by the poisoning of the water by nitrate and phosphate rich chemicals through run-off because of their filter feeding properties as a way to capture food, will absorb a great amount of unneeded nutrients making them far too dangerous to consume thus ruining the several shellfish businesses.

Fishy slides

Coral Reefs: Part 2

Map info. courtesy of Taylor

SIMILARITIES:
-all types of coral reefs
-need hard surface to grow
-all have reef flats, reef slopes, and reef crests
-variety of coral grow on reef flats and reef slopes
-fish live in all the reefs

DIFFERENCES:
-barrier reefs and atolls have spur and grooves
-fringing reefs grow close to shore
-barrier reefs are separate by a lagoon and atolls surround lagoons
-fringing reefs can extend all the way to shore
-no atolls due since Saipan is a raised-limestone island

Coral Reefs: Part 1

1. How is each reef structure formed?

Coral reefs begin to form when free-swimming coral larvae attach themselves to submerged rocks or other hard surfaces along the edges of islands/continents. As the corals grow and expand, reefs take on one of three major characteristic structures —fringing, barrier or atoll.

• Fringing reefs, which are the most common of all reefs, project seaward directly from the shore, forming borders along the shoreline and surrounding islands. Fringing reefs also grow on soft bottoms if there is even a small hard patch that lets the corals get a foothold. From there, the corals slowly creates their own hard bottom and expand themselves.
  
• Barrier reefs also border shorelines, but at a greater distance - sometimes as far as 100km. They are separated from their adjacent land mass by a lagoon of open, often deep water. The barrier reef consists of a back-reef slope, a reef flat, and a fore-reef slope, which corresponds to the reef slope of a fringing reef and has a reef crest.
• If a fringing reef forms around a volcanic island that subsides completely below sea level while the coral continues to grow upward, an atoll forms. Atolls range in size from small rings less than a mile across to systems well over 30 km in diameter.

2. Where is each reef structure found?

• Fringing reefs are found on rocky shorelines close to land.
• Barrier reefs, like fringing reefs, are found along the coast but farther out and separated by a lagoon.
• Atolls are found on top of sunken volcanic islands which lie underneath a layer of calcium carbonate.

3. What is the trophic structure of a reef?
The trophic structure of reefs revolves around nutrient recycling - which is basically zooxanthellae dependent since they are the dominant primary producers in the ocean. They take the coral nitrogen and phosphorus waste products and use the sun to create organic compounds which the corals need to survive. Without this process, corals would not be able to grow to their vast sizes since the water is usually poor in nutrients.

4. How does the location and type of reef influence the trophic structure?
Fringing reefs are close to shore so the water in which they live in gets runoff of a mixture of nutrients and pollution from the land. Barrier reefs, however, are farther out so they have access to water from the lagoon and the deeper ocean. Additionally, the fish and other organisms that live in the reefs add and subtract from the nutrients in that community.

5. Give examples of the types of corals found on reefs.
Common Name:

Branching Corals

Scientific Name:

Acropora Sp.

Type of Reef found on:

Reef Flat

Key Identification:

Stick like appearance & branching,

usually in colonies

6. Give examples of competition, predation, and grazing
Competition is an overgrowth or direct attack of one coral to another in their fight for growing space. A Crown-of-Thorns starfish is an example of predation since it eats and completely kills coral. Many types of fish eat coral polyps, but they don't eat enough to kill the whole organism. Grazing keeps coral populations in check.

Critical Thinking

Chapter 14

1. What factors might account for the fact that the vast majority of atolls occur in the Indian and Pacific oceans and that atolls are rare in the Atlantic?

Since corals are temperature dependent and nutrient dependent, they would most likely be found in the Indian and Pacific Oceans. Besides that, because of the Ring of Fire's location in the Pacific Ocean, atolls only be found there.

2. Scientists predict that the ocean will get warmer and the sea level will rise as a result of an intensified greenhouse effect. How might this affect coral reefs?

Disastrous effects may happen due to the amount of green house gases released. With a huge amount of CO₂ released into the atmosphere, it not only destroys the ozone layer, which would allow infrared heat to get trapped in the Earth’s atmosphere, causing the polar regions to melt thus allowing the sea level to rise; but, because of gas exchange, it would devastate the living organisms in the ocean. The vast amount of dissolved CO₂ would increase the amount of hydrogen carbonate ions, which in the overall process, would increase the acidity of the ocean (pH level) and retard the growth of corals because of the secondary buffer produced by the hydrogen carbonate ions – therefore diminishing the number of calcite ions, which are needed to combine with calcium carbonate ions that are needed to make exoskeletons. As for the living corals, they may die out too because of all the stress they would be receiving from the fluctuated environment (coral bleaching).

3. There are only a few reefs off the northeast coast of Brazil, even though it lies in the tropics. How would you explain this?

The reason why there are no coral reefs by the northeast coast of Brazil is because the Amazon River empties out there. The Amazon River carries silt which contributes to a murky appearance. Because of that, coral reefs could not be supported since sunlight wouldn't be able to reach the bottom.

Sea Floor Spreading

What is sea floor spreading?

The process by which new sea floor is formed as it moves away from spreading centers in mid-ocean ridges.

What are some of the major land forms that are created from plate movement?

Mountains, volcanoes, trenches, and the 7 continents were all formed from plate movement.

How were the Mariana Islands formed?

The Mariana Islands were formed by underwater volcanoes along the Marianas Trench. The northern islands consist of high volcanic islands while the southern islands consist of raised-limestone.

What evidence exists today that the plates are still moving and that the islands are ancient volcanoes?

The frictional movement of the Philippine plate under the Pacific plate above the asthenosphere which causes earthquakes and minute tremors.

What is an atoll?

An atoll is a coral reef that develops as a ring around a central lagoon.

Why are atolls mainly found on the Pacific?

Atolls establish themselves on coral reefs, which are found mainly in the Pacific Ocean because of its warm tropical climate.

Chapter 2: Critical Thinking

4. What are some of the major pieces of evidence for the theory of plate tectonics? How does the theory explain these observations?

According to Wegner’s hypothesis, which suggests that all continents had once been joined in a single “supercontinent,” named Pangea, the theory of plate tectonics was developed – a process that involves the entire surface of the planet. This theory is constituted of several evidences such as:

• Coal-deposits and other geological formation on either side of the Atlantic match exactly
• Fossils on opposite sides of the ocean that exactly match

In regards to Wegner's hypothesis on continental drift, as well as the theory on plate tectonics, it is quite obvious that the evidences stated above are true, since the fossil records on biotic and abiotic life supports it.

Adaptations and Biology of Birds, Reptiles, and Mammals

Reptilia

Saltwater crocodile

The saltwater crocodile can live in fresh water, salt water or brackish (mixed) water. If it is living in salty water, its kidneys and tongue allows the excretions of salt. It has eyes and nostrils high up on its head and a broad tail with webbed feet for swimming. It feeds on almost any meat it can get. Animals that live in the water and near the water may/will become food for the saltwater crocs - even people!! A hunting tactic that it has developed includes the art of camouflage - where it stealthily moves underwater with only its nostrils above the surface. Besides the saltwater crocodile's art of stalking its prey, it also has its elusive death roll that it uses in order to tear flesh which gives an instantaneous death when clamped between both jaws.

Aves
Penguins

Penguins are superbly adapted to an aquatic life. Their wings have become flippers - and contain a denser bone material that is useless for flight in the air, in water however, penguins are astonishingly agile. Within the smooth plumage a layer of air is preserved, ensuring buoyancy. The air layer also helps insulate the birds in cold waters. On land, penguins use their tails and wings to maintain balance for their upright stance. All penguins are countershaded - that is, they have a white underside and a dark (mostly black) upperside. This is for camouflage. A predator looking up from below (such as an orca or a leopard seal) has difficulty distinguishing between a white penguin belly and the reflective water surface. The dark plumage on their backs camouflages them from above. Diving penguins reach 6 to 12 km/h (3.7 to 7.5 mph), though there are reports of velocities of 27 km/h (17 mph) (which are more realistic in the case of startled flight). The small penguins do not usually dive deep; they catch their prey near the surface in dives that normally last only one or two minutes. Larger penguins can dive deep in case of need. Dives of the large Emperor Penguin have been recorded which reach a depth of 565 m (1870 ft) and last up to 22 minutes. Penguins either waddle on their feet or slide on their bellies across the snow, this allows them to conserve energy and move relatively fast at the same time. They also jump, with both feet together. Penguins have an excellent sense of hearing. Their eyes are adapted for underwater vision, and are their primary means of locating prey and avoiding predators; in air, conversely, they are nearsighted. Their sense of smell has not been researched so far. They are able to drink salt water safely because their supraorbital gland filters excess salt from the bloodstream. The salt is excreted in a concentrated fluid from the nasal passages.

Mammalia
Baleen Whale

Like all mammals, whales: breathe air into lungs, are warm-blooded, feed their young milk from mammary glands, and have some hair. The body is fusiform, resembling the streamlined form of a fish. The forelimbs, also called flippers, are paddle-shaped. The end of the tail fins provide propulsion by vertical movement. Most species of whales bear a fin on their backs known as a dorsal fin. Beneath the skin lies a layer of fat. It serves as an energy reservoir and also as insulation. Whales have a four-chambered heart. The neck vertebrae are fused in most whales, which provides stability during swimming at the expense of flexibility. Whales breathe through blow holes located on the top of the head so the animal can remain submerged. Whales have a unique respiratory system which allows them to stay underwater for a long period of time without needing to re-surface to breathe. There are similarities between the ears of whales and humans, whales’ ears have specific adaptations to their underwater environment. In humans, the middle ear works as an impedance matcher between the outside air’s low-impedance and the cochlear fluid’s high-impedance. In aquatic mammals such as whales, however, there is no great difference between the outer and inner environments. Instead of sound passing through outer ear to middle ear, whales receive sound through their lower jaw.

The Shape of Life: Episode 2 - Life on the Move

From the stationary sponge to all the moving creatures in the world, cnidarians, a group that includes corals, sea anemones, sea pens and jellyfish, were the organisms that started it all. It is first thought that these organisms evolved with an evolutionary edge of motion in order to food, and indeed this is true.

Along with their non-hydrodynamic body shape, each species of jellyfish has a specific propulsion movement in order to obtain their food. When propelling through the water, they push the water towards their tentacles, allowing them to capture prey - a completely new innovation in comparison to the stationary sponge.

Fish Resources

Fishes may not be the most diverse species in comparison to insects, but they are surly one of the most important. In recent news, many of the fish populations around the world have been declining due to anthropogenic interactions, as well as the fact that 1 out of every 4 people have fish as their main part of their diet. Therefore, it’s quite obvious that fish are being over fished.

Most of the businesses may have been affected by it already, seeing a decline in the amount and size of the fish. This has already been noticed here in the CNMI, and yet, people continue to dump out their trash into the ocean telling their egocentric-selves that the ocean will clean it up for them. Ever seen a diaper fish? And no, it’s not literally a diaper… People need to open their minds and actually think what they need to do in order to protect not only the fishes, but as well as both fresh and salt water.

Sea Floor in a Shoebox

Chapter 8 Critical Thinking

1. Hagfishes and lampreys are the only living representatives of a very ancient group. Why do you suppose there are still some of these jawless fishes around?

For one thing, nature revolves around the fat that those organisms that are more successful than others will live longer. As for both hagfishes and lampreys, they are the most well adapted species of the class Agnatha, since they are still living today. It’s simply when you place natural selection into play – only the best survive. Hagfishes and lampreys may have not been the “top” predator when before, but in the overall outcome, they are the most successful ones since they are “living fossils.”

2. A deep-water shark, new to science, is collected for the first time. The specimen is studied in detail, but its stomach is empty. How could you get a rough idea of its feeding habits? The specimen is a female, and its reproductive tract is found to contain 20 eggs. Can you tell the type of development characteristics of this species?

· A factor which makes this question very broad is the fact that there is little to no information for this scenario. And although hypothesis may be assumed, giving that it has been studied in detail and has an empty stomach, one can derive the answer to be that the shark is a filter feeder, or in such cases that it has a slow metabolic rate because of its lifestyle, which therefore means that the food that has been consumed prior to its capture has moved from the shark’s stomach and into it’s intestine.

· Out of the three types of shark egg development – viviparous, oviparous, and ovoviviparous, as well as the factor that it has not been observed in a contained or wild environment, there would be no way of proving the type of developmental characteristics of the newly found species yet.

3. Individuals of some species of bony fishes change sex, some to maintain more males than females, others more females than males. What are the advantages and disadvantages of each situation? Are there any advantages and disadvantages in having an equal number of males and females?
• The advantage for maintaining more males than females is that it would ensure that the most dominant male(s) would be able to mate to pass on their traits making their offspring genetically advantageous in comparison to other offsprings whose parents may have not been the dominant of the group; however, due to the amount of females, there would be less offspring.
• An advantage that more females than males offers is that that certain species would produce more offspring; but, because of that, the survival rate of the offspring would be low.
• As for the equal amount of males and females, for one, there would be a higher amount of offspring > to the scenario where there would be more males then females; yet, there would be an average survival rate, as for the factors dealing with genetics, well; it would quite hard to determine this factor since juvenile fishes are exposed to a vast amount of danger when they are maturing.

DISSECTION: SEA STAR (STARFISH)

Pictures found in: Sea star

Digestive System: The digestive system of a sea star is quite complex, with its mouth on its underside and anus on the top. They feed by everting, part of their stomach inside out through the mouth to envelop the food. The stomach then secretes digestive enzymes produced by large digestive glands that extend into the arms. The digested food is carried into the glands for absorption and the stomach pulled back inside the body.

Circulatory System: Sea stars do not have a circulatory system.

Nervous System: Sea stars have a network of nerves that coordinates movements of tube feet and spines in the absence of a brain.

Excretory System: There is no formal excretory system present in sea stars.

Reproductive System: Sea stars reproduce by means of broadcast spawning where the males and females discharge there eggs and sperm into the water where they are fertilized.

Integumentary System: The integumentary system of a sea star consists of five arms and spines or bumps all over its body. The spines are protective and also help with respiration.

Body Plan: Unlike many organisms, the sea star and the rest of its echinoderm family have a pentamerous radial symmetry and also lack a head. They have no anterior or posterior end or even a dorsal or ventral side. It is useful to refer to one of its surfaces as oral, because that is where the mouth is located, and an opposite side - referred to as aboral. They also have an endoskeleton similar to humans, that is secreted within the tissues, rather than externally.

Sea stars live in temperate and tropical waters. Some are bottom dwellers while many live mostly in shallow marine environments. They eat scraps of food, algal mats, or even deceased organisms. Others are active predators that will attack and eat clams, snails, sponges, corals, anemones.

DISSECTION: CLAMS

Pictures found in: Clams

Digestive System: Water is drawn into siphons formed by the fusion of the edge of the mantle which leads to its mouth then to its digestive glands and then to its intestines.

Circulatory System: Water is siphoned into its mantle which passes over its gills, where oxygen is then diffused into the blood and pumped through its body via impulses of the heart. CO2 is then diffused out as O2 takes its place within the gills.

Nervous System: A clam has no formal nervous system, but it senses its environment with the use of its ganglia that is located above the mouth and foot, cells along the edge of its mantle react to both light and touch.

Reproductive System: Each clam has a gonad - with each being either a male or female. They reproduces sexually through means of broadcast spawning where both egg cells and sperm cells are released into the water, where they get fertilized.

Integumentary System: Enclosed in a CaCO3 shell that is adapted to protect its soft body from predators. Its foot is used for locomotion.

Body Plan: Its soft interior is protected by a hard shell composed of CaCO3. It's body is covered by a mantle: a thin layer of tissue that secretes the shell. It is unsegmented and bilaterally symmetrical and has a ventral muscular foot that is used for locomotion.

Different species of clams live in different environments - ranging from fresh to saltwater. Clams are simple organisms. Clams are molluscs because they are soft bodied animals with an internal or external shell. The name of the phylum is derived from Latin word molluscus meaning soft.

DISSECTION: SQUIDS

Pictures found in: Squid

Digestive System: The squid has a flow through digestive system. Food enters their digestive tract through the squid's mouth and is digested into feces which is excreted through the anus.

Circulatory System: The squid has a closed circulatory system with three hearts. H2O and O2 enter the squid's body through its mantle where the respiratory exchange takes place in the gills. CO2 and H2O are then expelled from the body through a siphon.

Nervous System: A squid has a very complex nervous system compared to most invertebrates. Having They have a large brain that coordinates and stores information received around its environment. Also, by using their giant nerve fibers, they can rapidly conduct impulses, which allows them to capture their prey at great velocities.

Excretory System: The excretory system of a squid if also known as a metanephridium, which consists of a ciliated funnel opening into the body cavity and to a duct which opens to its exterior. These ciliated tubes assist in the pumping out waste products.

Reproductive System: The reproduction in squids is external - where the male uses a modified arm to transfer a spermatophore to the female.

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.

Body Plan: The body plan of a squid includes its head and arms, mouth, and eyes.
The head end of the squid bears 8 arms and two tentacles. These tentacles do not grow back if severed.
The mouth of the squid is equipped with a sharp horny beak mainly made of chitin and proteins, and is used to kill and tear prey into manageable pieces.
The eyes of the squid, found on either side of the head, contains a hard lens, which is used much like the lens of a camera or a telescope for focusing; rather than changing shape, like a human eye, it moves mechanically.

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.

DISSECTION: CRAYFISH

Pictures found in: Crayfish

Digestive System: The digestive system of a crayfish is simple compared to other vertebrates, but far more complex than other invertebrates. The tract is composed a foregut (enlarged stomach that is specialized for grinding), the midgut, and the hindgut - leads to anus and regulates salt and water as well. The digestive gland secretes digestive enzymes and aids in the absorption of the products of digestion.

Circulatory System: The circulatory system of the crayfish is centered on a muscular heart with dorsal, anterior, and posterior arteries leading away from it. The heart pumps the blood across the gills which absorbs the oxygen from the water and sends it back to the heart and adjoining arteries.

Nervous System: A crayfish's nervous system is composed of a ventral nerve cord fused with segmental ganglia, and the supresophageal and subesophageal ganglia.

Excretory System: The excretory organs are also called the antennal glands are located at the base of the second antenna. They excrete the waste products of blood filtration.

Reproductive System: Crayfishes reproduce sexually during the spring.

Integumentary System: The crayfish has a jointed exoskeleton which they shed to allow growth.

Body Plan: The body is divided into two parts: the cephalothorax and the abdomen. The cephalothorax has sensory, feeding, and locomotion functions and the abdomen has locomotion and visceral functions.

Crayfish live in freshwater environments - any where there is a rich muddy water that allow them to hide.

Homework: Invertebrates

1. Name of organism (Classification kingdom, phylum, class, order, family, genus, species)

Picture found in: NOAA: Horseshoe Crab
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Cheilcerata
Class: Merostomata
Subclass: Xiphosura
Order: Xiphosurida
Family: Limulidae
Genus: Limulus
Species: polyphemus

2. Habitat (where in the ocean does it live)
Horseshoe crabs can tolerate a wide range of temperatures and have distinct physiological processes that enable them to survive in areas of low oxygen environments. Adult horseshoe crabs have been found burrowed into muds and intertidal flats at low tide. They can move out of the water during spawning and survive extended periods of time out of the water as long as their book gills are kept moist. Since horseshoe crabs go through inshore and offshore migrations, they are particularly affected by environmental degradations in both estuarine and oceanic habitats.

3. Food source
Adult horseshoe crabs feed primarily on marine worms and shellfish, including razor clams and soft-shelled clams, and since they lack jaws, horseshoe crabs use the spiny bases of their legs to crush and grind their food and to push it into their mouths.

4. Description of life cycle (egg to death)
After fertilization, the eggs begin to develop into trilobite larvae. By day five, miniature legs are visible inside the translucent egg. On day six, the larvae molt for the first time. On day seven, the outer membrane of the egg ruptures and the inner membrane swells to replace it. By the end of the second week, the larvae will molt twice for its preparation of hatching. (The rate of which the egg hatches is determined by the tides and warmth of the sun which ranges from a two week period ~ three or four weeks or even months.) Upon hatching, their digestive system is not yet functional; instead, they swim around for about a week absorbing the yolk sac as their digestive systems mature. Around day 21, the larvae settle from the water column and onto the soft sediments; there, they shed their shells, their bodies expand, a telson grows, and chitin hardens the new carapace. Horseshoe crabs molt an average of three or four times a year, where sub-adults (horseshoe crabs that are five to seven years old) appear to molt annually, until they reach until they reach sexual maturity (males = 16 ; females = 17). Their lifespan is currently unknown, but some scientist think that they may live up to 20 years or more. As for the unlucky ones, they may get eaten during their larvae form or even by birds when they are struggling to get to their upright position.

5. How does it move (if it moves)
Horseshoe crabs move by the use of their seven pairs of leg-like appendages found under their shell, which are used for gathering and eating food as well.

6. Unique characteristics
-One of the oldest living life forms
-Resemble trilobites (during their larvae stage)
-Their blood is of value to medical science which is harvested by biomedical labs and used to test the sterility of surgical instruments before surgery

7. Role in the ecosystem
A horseshoe crab is virtually a "walking hotel," with several numbers of creatures living attached to its shell: mollusks, bryozoans, sponges, flatworms, diatoms, fungi, and bacteria. Horseshoe crabs also play a big role in terms of bird migratory patterns where recent bird count shave shown alarming decreases in numbers due to horseshoe crab over-harvesting.

Critical Thinking Questions: Mass Re-Collection

Critical Thinking

Chapter 1

1. In Chapter 1 it was explained that the statement “There are mermaids in the ocean” is not a valid scientific hypothesis. Can the same be said of the statement “There are no mermaids in the ocean”? Why?

Yes, it is not a valid hypothesis as well. Both statements – “There are mermaids in the ocean” and “There are no mermaids in the ocean” are the same, since there is no factual documentation of any mermaids so far; therefore, any justification and hypothesis stating that “there are…” and “there are no mermaids in the ocean” are and should be irrelevant.

Chapter 3

3. If you owned a seaside home and a bad storm brought heavy winds and high surf to your coastline, would you prefer it to be during a new moon or a quarter moon? Why?

Hopefully it would be during the quarter moon because the tidal influence based on gravitational calculations^* would not be as great as the tidal influence that both the moon and Sun would have during a new moon.

^*F_{G moon} = Gm₁m₂ / r²

F_{G sun}= Gm₁m₂ / r²

F_{G sun} > + F_{G moon} ≈ tidal influence during the new moon and Sun

Chapter 4

1. During the day, algae carry out both photosynthesis and cellular respiration, but at night, when there is no light, they can only perform respiration. Small, isolated tide pools on rocky shores are often inhabited by thick growths of seaweeds, which are algae. Would you expect that amount of oxygen in the water to differ between night and day? How?

Because the amount of dissolved oxygen is proportional to the temperature of the ocean, it can be deduced that there would be more oxygen dissolved at night than day. Yet, there is a factor that should be taken in consideration – the water’s heat capacity. During the day, the water remains warm while the land remains hot, in contrast, at night, the water becomes cool and the land becomes cold because they are exposed to the zero degree Kelvin space. Therefore, in conclusion, I would suggest yes – in that there would be a difference in the amount of dissolved oxygen in the water in the day <>

Chapter 5

2. An autotrophic protist, such as a diatom or a dinoflagellate, can evolve into a heterotrophic protest (and therefore a protozoan) simply by losing its chloroplasts. Under what conditions might this take place?
   

For an autotrophic protest having an evolutionary stage, it may be comparable with the evolutionary stages of insects (as an example). The protist, it goes through an evolutionary process where the organism’s biological structure goes through several changes during its juvenile stage – thus losing its autotrophic attributes and gaining heterotrophic values, which may be triggered by its maturity or even a chemical change in the water thru means of natural or artificial alteration.

Chapter 6

2. Only very few flowering plants have invaded the oceans, but those that have are very successful. What are some possible reasons for the small number of marine flowering plants? How do those that have taken the step manage to thrive in some environments?

Here are some possible reasons for the small number of marine flowering plants:

· Inadaptability to salt water

· Temperature dependent

· Competition

· Ability to withstand wave crashing zones

· Tidal range

Over a process of natural selection, the many flowering plants that thrive in these environments have developed highly productive meadows and forests along the shore.

Class Work: Division and Multiplication

1. What is DNA?
DNA - the Blueprint of Life
*Every living organism contains within itself the information it needs to build a new organism.
2. What are the 4 bases?
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?
Phosphate backbone, double helix.
4. What are the specific base pairs?
(adenine,thynine) (guanine,cytosine)
5. How does the pairing rule effect the shape and structure of DNA?
A and T makes a 2H and G and C makes 3H bond, which restricts the structure of the DNA block during its copying process.
6. What does the DNA do during cell division?
DNA unwinds so it can be copied and the copies transferred to new cells. DNA also unwinds so that its instructions can be used to make proteins and for other biological processes.
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, 639, 221
40 minutes
It is packaged in a tight coil in the nucleus of a cell
8. How many base pairs does Human DNA have? How long does it take to replicate? How is the DNA packaged in the cell?
3 billion + base pairs
12 – 24 hours
In the nucleus

1. What is RNA? How different is it from DNA?
RNA - a Blueprint Copy
Ribonucleic acid is a blueprint copy of DNA. RNA is only made of a single strand. Furthermore, the base T, thymine, is replaced by U, uracil in RNA.
2. How are the RNA messages formed?
RNA messages are formed by the grouping together of 3 of the letters to create a triplet or codon. The codons line up and form a chain of codes that create a message.
3. How are the RNA messages interpreted?
Ribosomes read the messages and then attach the amino acids together to make up a protein.

1. Describe cell cycle.
Gap 1 phase: cell growth begins
Synthesis phase: chromosomes duplicate and divide; cell growth continues
Gap 2 phase: cell reaches proper size
Mitosis phase: cell division
*chromosomes are stored in the cell nucleus
*CDK and cyclin are the key molecules that control and coordinate cell division
2. What is nuclear division?
Nuclear division is the division of the nucleus and genetic information into more than one cell from a parent cell, usually through mitosis or meiosis.
3. What is interphase?
When the cell or nucleus is not in mitosis.
4. Cytokinesis?
The stage in meiosis in which the cytoplasm of the cell is divided after the nuclear division.
5. Homologous chromosomes?
Pair of chromosomes that have the same genetic sequencing because they come from the same parent cell.
6. Phases of mitosis.
Prophase
Metaphase
Anaphase
Telophase
Interphase
7. Phases of meiosis and how it is different from mitosis.
Early prophase
Late prophase
Metaphase
Anaphase
Telophase
Second Telophase
*Meiosis is different from mitosis because the cell goes through 2 divisions instead of just one and results in 4 daughter cells instead of only 2.
*Cells that go through mitosis are called diploid cells because it has 2 complete sets of chromosomes. Cells that go through meiosis only have a single set of chromosomes that is completed when the female and male gamete are united.
8. Describe the process and purpose of crossing over.
Crossing over occurs only when the sperm and egg chromosomes pair up and swap genetic information, reducing the number of chromosomes to a complete set. It is important because it allows the number of chromosomes the normal number and also allows the genetic information to remain present in the cell.

Homework: Photosynthesis and Cellular pRespiration

picture found at: Biology Corner

In photosynthesis, CO2 and H2O are used to make glucose. The energy for this process comes from sunlight, where O2 is given off as a by-product since it needs CO2 than O2.

picture found at: ProgressiveGardens

Respiration is basically the opposite of photosynthesis. Respiration breaks down glucose, using oxygen, and produces oxygen, and produces carbon dioxide and water. The energy that originally came from the sun is then made available to the organism.