R. Sylvatica's Thawing Process

The results of the study found that there was a significant difference in Daphnia’s response when exposed to a cold stimulus in the form of crushed ice, compared to room temperature water. Thus, the null hypothesis was rejected and the alternate hypothesis was accepted. These findings could be due to the fact that Daphnia magna are cold blooded and were trying to swim away from the ice cubes that were attached to the bottom of the mesocosm opposite to the counting area. These results support the idea that Daphnia experience a negative thermotactic reaction when exposed to colder water compared to room temperature water.

The objectives in this laboratory were to be able to calculate the freezing point depression among three trials of unknowns, be able to correctly measure the freezing points of p-xylene, and to be able to calculate the molar masses of the unknowns by found freezing point depression values. This was done to be able to understand and apply a concept names supercooling. Supercooling is when a liquid is put far under its original freezing point and remains a liquid or gas. This happens when a substance is cooled so quickly that it’s easier for it to stay a liquid than to crystalize, until it reached its nucleation point and begins to heat up returning to its freezing point (image 4). The supercooling of p-xylene was observed in three

We have noticed in other experiments that smaller animals have a higher surface-to-volume (SA/V) ratios than larger animals with a lower SA/V. After reviewing through articles, we hypothesized that endotherms with small bodies will have a higher metabolic rate than endotherms with large bodies. We tested this by making 6 clay cubes (different sizes) and placed them in ice for 10 minutes and measured them in 2-minute intervals. Our results supported our hypothesis because the larger clay with the smallest SA/V had the slowest cooling rate while the smallest cube with the higher SA/V had the fastest cooling rate.

In a behavioral hypothermia study done by Tattersall & Boutilier (1997), behavioural hypothermia responses were observed in bullfrogs to show the advantages of maintaining oxygen levels during hypoxia. During the winter months, frogs hibernate and during this time metabolic rate largely decreases as they live on the bottom of ponds in very hypoxic water. However, these adaptations are only seen long term. As shown in Figure 2, oxygen consumption increased over time at 5֯ C. Therefore, it is expected that oxygen consumption in frogs would decrease over a longer period of time.

The Rana sylvatica, or wood frog, portrays itself in an unassuming manner. However, the Rana sylvatica undergoes a fascinating physiological response when exposed to extreme cold. For exemplification, the Rana sylvatica spends the entire winter in an unconscious state. Superficially, this is commonplace in the animal kingdom. Many animals, including bears, spend the winter in a deep slumber, which is made possible due to large amounts of insulating adipose tissue. The Rana sylvatica, however, does not try to insulate itself from the winter environment. Instead, it becomes frozen. This is fascinating because tissue does not normally survive frozen environments. Cells are full of water. When water freezes, it forms jagged crystals. These crystals, obviously, will puncture the cells and injure a body. This is why we cannot survive a deep, frozen sleep. Despite this, the Rana sylvatica does something fascinating. When it senses cold, the Rana sylvatica moves the water out of its cells and into the abdominal cavity. Furthermore, the Rana sylvatica moves glucose from its liver and into the bloodstream. This allows the freezing temperature to drop significantly. This is because the sugar literally "blocks" ice crystals from forming. All together, the

DeVries and his colleagues originally went to Antarctica to study respiratory metabolism in fish but what he noticed was that when they caught the fish and put it in an aquarium at freezing point seawater -1.09, the fish survived except for some of the deepwater fish. When those fish touched the ice that formed on the cooling coils of the aquarium, they froze.

When the creatures still managed to reanimate after thawing, the team looked for physical qualities that might explain this superior resilience. It found that the Alaskan frogs stockpile astonishing amounts of a complex sugar called glycogen in their livers, which grow 1.5-fold relative to body mass as the amphibians prepare for winter. “This frog is like a walking liver,” says zoologist Jon Costanzo of Miami University in Oxford, Ohio, who led the research. The liver later converts this glycogen to glucose, a known cryoprotectant that quickly gets distributed to all the cells in the body when temperatures drop. The Alaskan frogs also accumulated about three times as much of the cryoprotectant urea in their blood plasma compared with frogs

Imagine a world with no trees, no healthy grass, no glaciers, or no living creatures at all. The cause of this tragedy could be the increase in heat in the Earth’s atmosphere due to global warming. If global warming continues to increase, the world will be left empty. The Earth has been around for a long time, and many feet have walked on it, but no one has walked on this Earth without trees, grass, or creatures. With global warming, the Earth’s meteorology gets too warm, and all of the glaciers will start to melt. Global warming occurs when an increase in the carbon dioxide levels causes the temperature of the Earth’s atmosphere to rise. The Earth’s meteorology is often a subject explored in literature. For example, “Chronicles of Ice” talks

One animal that prepares for the arrival of winter is the Rana Sylvatica, it is a species of wood frog’s that freezes it self through winter and then comes back to life. The tiny amphibians can survive for weeks with an incredible two-thirds of their body water completely frozen to the point where they are essentially solid frog sicles . Even more incredible is the fact that the wood frogs stop breathing and their hearts stop beating entirely for days to weeks at a time. In fact, during its period of frozen winter hibernation, the frogs physical processes from metabolic activity to waste production grind to a near halt. What’s more the frogs are likely to endure multiple freeze or thaw episodes over the course of a winter.The frogs have

The sugar molecules don’t fit into this, so when you freeze the water, the water freezes first and the sugar stays behind in the liquid part as the ice develops. Sugar makes the ice harder to form, therefore lowering the freezing point. By lowering the freezing point, it keeps the ice from re-freezing as easily, helping to melt the rest of the ice.

Colligative properties, such as boiling point and freezing point, are dependent on the amount of solutes added, not necessarily their identities (LibreTexts, 2018). A fascinating concept related to freezing points is Supercooling. Supercooling is a state where liquids do not form ice even when they reach temperatures below their normal freezing point; they are trapped in a metastable state (Esrf.eu, 2018). The best example of this is clouds at high altitudes: they contain tiny droplets of water that do not have seed crystals, and therefore do not form ice despite the low temperatures (Esrf.eu, 2018). The concept of freezing point depression is applicable in many parts of everyday life.

A live specimens of (Xenopus leavis ) were removed from a bucket, tweezers were used to open its mouth and bone crushing scissors were placed between its mouth and behind its eye. The top portion of the head was then cut off, killing the frog instantly. A dissecting needle was gently shoved in the spinal cord and it was moved around in order to kill the nerve in the spinal cord. The frog was placed onto its back and dissecting scissors were used to cut the skin across the abdomen. The frog was pinned down as one member then pulled the skin off the frog down towards its lower limbs. This process was seen as “pulling off the pants”. Ringer solution was added to the tissues using a clean pipette. One leg was chosen and dissecting scissors were

Frogs, toads, caecilians, and salamanders are the members of the class Amphibian (amphi- meaning “on both sides” and bios- meaning “life”). These members always require water for reproduction. Most Amphibians undergo metamorphosis, which is a usually degenerative pathological change in the structure of a particular body tissue. And, in the case of Amphibians, it is the changing of a tadpole into

In animal cells, the movement of water into and out of the cell is influenced by the relative concentration of solute

There are three types of environments in which cells are located which include isotonic, hypotonic and hypertonic. In an isotonic environment, the amount of water and solute are the same both inside and outside of the cell. As water drifts into the a cell, the same amount flows out creating a balanced environment both inside and outside of the cell. When there is a high level of water on the outside of the cell and a high amount of solute inside the cell, water will be drawn inside of the cell creating a hypotonic solution. The increase in water inside the cell causes the cell to become engorged and erupt. In a