Wednesday, April 27, 2011
The actual time it takes for an arm to regenerate into an adult star fish varies. This phenomenon is regulated by both exogenous (seasonal changes, environmental stimuli)and endogenous factors (body size, humoral and nervous factors). Several studies have been done on this topic and it appears that within 6 weeks the animal has made significant growth advances in replacing the lost body parts.
Monday, April 18, 2011
Many creatures are able to secrete venom but many believe the deadliest is the Sea Wasp, a box jelly fish that is found in Australia. The venom from this creature is able to kill 60 people and over 100 deaths have been attributed to this sea animal.
The Sea Wasp is not aggressive but it swims along at about 5 mph with it's tentacles flowing behind. It is easy for other animals and sometimes humans to get stung by these trailing tentacles.
Thursday, April 7, 2011
A Water Lily is classified as an aquatic plant and it's roots are attached to the bottom of the lake or pond. So I think what you are really asking is the length of the stem that then attaches to the root at the muddy bottom.
In researching your answer I found a lot more information on how to get rid of these pretty but sometimes invasive plants than true facts about their structure. It appears that the stem length fluctuates with the depth of the water but can be 12-15 feet in length.
Wednesday, April 6, 2011
Carnivorous plants are really interesting but we may some misconceptions on how a venus fly trap works.
The traps consist of two clamshell-like halves, lined with guard hairs and very small nectar glands. In their resting position the traps are held open at 45°-60°. A healthy plant may have from 3 to 12 or more traps.
The interior surface of each leaf is filled with microscopic digestive glands, giving the leaf surface a fine bumpy appearance. Each inner leaf half usually has three small delicate trigger hairs in a triangular pattern. Most of the time, for the trap to close, any one of these trigger hairs must be touched twice, or any two hairs touched one after the other. In very warm temperatures one touch may be enough. The longer the period between the two stimuli the slower the closure. The best closing response seems to happen when both stimuli occur within 40 seconds. Each trap will close about 10 times before it will no longer respond.
The time delay for trap closure seems to have some survival advantage. A single stroke caused by a brisk breeze or raindrop will not make the plant spend unnecessary closure energy on non-food. The double stroke will often allow prey to enter the center of the trap and be better positioned for capture. If the trap captures non-organic matter or misses its prey, it will open usually within 24 hours. A trap may take 3 to 5 days to digest completely entrapped prey.
Monday, April 4, 2011
The largest tree is 275 feet - a Giant Sequoia. The largest animal is the Blue Whale at 110 feet. That means that the plant wins the title of largest living single organism.
C4 plants are plants that use a supplementary method of CO2 uptake which forms a 4-carbon molecule instead of the two 3-carbon molecules of the Calvin cycle. These plants are able to handle higher temperatures and higher light intensity than C3 plants. C4 plants do require more ATP than C3 plants but also make more glucose per given leaf area and grow more quickly.
Plants that are C4s include sorghum, sugarcane, crab grass, millet,corn,Bermuda grass,amaranth,and nut grass.