Wednesday, January 19, 2011

Adaptation - Group 1

Q1. How do mangrove plants such as Avicennia obtain oxygen when their roots are buried in the mud?

-Mangrove plants have physically developed their roots exposed to the air. Mangroves developed the aerating component. The above-ground part of the root system will enable the plants to allow the gas exchange process.

-Through root hair and their capillary passages, the absorption of water and nutrients occur, even in anaerobic soil condition. The movement of nutrients through the vessels and from the substrates is controlled by the osmotic system.


Q2. How are xerophytes adapted to survive prolonged drought?

-Succulent (plants that store water) leaves and stems hold and store moisture.

-Fewer leaves also reduce the amount of transpiration.

-Traditional leaves are replaced with spines or thorns (aka needle-like leaves).

-Able to store water whenever it becomes available, accumulating large amounts of moisture during rainy seasons.

-Xerophytes close up their pores, called stomata, during the day, allowing them to avoid major water loss. They will instead open them at night; and though some water loss may occur through nighttime transpiration, it is very little.

-Slowly shrink up as moisture is lost, surviving on their stored up water within the leaves or stems.

-Has extensive, yet shallow, root systems that store water as well.

-Becoming dormant during dry periods and then regrow once moisture returns.


Q3. How do polar bears survive in regions where temperature are constantly freezing?

-Polar bears are well adapted for survival in the Arctic. They have:
    •A white appearance, as camouflage from prey on the snow and ice
    thick layers of fat and fur, for insulation against the cold
    •A small surface area to volume ratio, to minimize heat loss
    •A greasy coat, which sheds water after swimming

Q4. How do deep-sea anglerfish locate its prey in darkness?

-A piece of dorsal spine that protrudes above their mouths like a fishing pole (only found in females)

-Waves it back and forth to attract prey

-Their mouths are so big and their bodies so pliable, they can swallow prey up to twice their own size.

-When its prey gets close enough, the angler snaps it up with its powerful jaws and swallows it whole.


Q5. Why can't a saltwater fish survive in freshwater aquarium?

-Saltwater fish are adapted to the salinity of the saltwater.

-When moved to a freshwater aquarium, they are unable to adapt to the less concentration of salt in the given freshwater.


What are the differences in pH between seawater and freshwater ponds?

- average pH of freshwater ponds: 7

- average pH of seawater ponds: 8

- Difference in pH level: approximately 1

Source: Chapter 5 the properties of seawater. (n.d.). Retrieved from

Done by: Eunice, Kang Yan, Ren Chang, Kok Yin, Celine

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