the mysteries of science

Tuesday, August 24, 2010

i left what i needed to say here @12:38 PM

Plants that grow in deserts must be able to withstand long droughts and high temperatures. You might think that these kind of plants are scarce, but yet, there are amny plants that are able to grow, though they are widely scattered.

Most common desert plants are small desert plants, called ephemerals. These plants produce seeds that lie dormant for years, but they complete their life cycle in six to eight weeks after a rainstorm.

E.g. The chief plants in Australia's Simpson Desert are normally hardy shrubs and spinifex grass. But millions of flowering ephemerals spring to life after rain, producing a scene of beauty and food for insects, birds and other animals. But the plants are soon gone after their life cycle ends, and only their seeds remain.

Some plants are drought-tolerant. This means that they can survive without water by either conserving their water of obtaining water through other means.

E.g. The creosote bush in North America is able to survive an entire year without a single drop of water. While some plants, such as the ocotillo (or coach whip), shed their leaves during droughts and regrow them after rain. Other plants called succulents, like the cacti of Americas and euphorbias in the Old World, have fleshy stems or roots which are capable of storing large amounts of water. succulents often have waxy surfaces to reduce water loss or hairs to refect sunlight or act as insulators. Others close their stomata during the day or have unpleasant taste to prevent animals from taking their water. They also have deep root systems.

The largest cactus species in the world is the saguaro, and it often reaches a height of 15 metres or 50 feet. It has an extensive root system and can store up to 6 tp 8 tonnes of water in its trunk and branches. Smaller cactus species provide water for thirsty travellers.

Source: Deserts by Keith Lye

&the beauty of time is that once it starts ticking, it'll never stop.

i left what i needed to say here @6:28 PM

Cells, Tissue and Organs/ Osmosis and Diffusion

A cell is a single unit of life. It contains many organelles such as the nucleus or chloroplasts.

Gene, Chromosome, Nucleus.

smallest------------------------>biggest.

Chloroplast, Palisade Mesophyll Cell, Tissue, Organ System, Organism

smallest-------------------------------------------------------------------------->biggest

Protoplasm refers to the organelles in a cell.

What is the plant tissue that transports water?

Xylem vessel.

What is the cell that transports oxygen in humans?

Red Blood Cell.

Xylem vessel has no protoplasm, true or false?

TRUE. It does not have any protoplasm so as to not hinder water movement.

I have long threads that can carry information. What am I?

Chromosome.

Which animal cell, when placed in distilled water, will burst?

Red blood cell. It will burst as it does not have a cell wall.

What type of leaf does not completely contain chlorophyll?

Varigated leaf. (The green parts contain chloroplasts and the white parts DO NOT CONTAIN CHLOROPLASTS.)

Photosynthesis can occur when there is respiration, true or false?

True.

Respiration occurs all the time, true or false?

True.

What should one do to only allow respiration to take place in plants?

Place the plant in a dark room, with no sunlight.

How does one test for carbon dioxide?

Limewater. The limewater will turn chalky, into a white precipitate, when in contact with carbon dioxide.

How do we know that carbon dioxide is needed for photosynthesis?

Have 2 plants, use one as a control. Cover both plants with a plastic bag, and in one, place soda lime. The soda lime will absorb all the carbon dioxide.

What are the raw materials needed for photosynthesis?

Water and Carbon Dioxide.

What are the conditions needed for photosynthesis?

Chlorophyll and Sunlight.

What is the end product of photosynthesis?

Oxygen and Glucose.

What is glucose used for?

It is used for respiration in plants.

Mitochondrion (singular form), Mitochondria (plural form)

It's function is to transport oxygen in cells, which will transport oxygen to different parts of the body. The muscle cell and the sperm cell contains the most mitochondria.

Water diffuses through partially permeable membranes like the visking tubing faster than glucose. It diffuses by osmosis because there is a higher concentration in the water than in the glucose. The glucose can diffuse through a visking tubing, but it diffuses slower than water.

Potato A is placed in a concentrated salt solution. Water will leave the potato by osmosis. There is a higher water concentration in the cell sap than in the salt solution. The potato will become soft and flaccid.

Potato B is placed in water. Water will enter the potato by osmosis. There is a higher water concentration in the water than in the cell sap. The potato will become hard and turgid.

Starch can pass through cell walls, because the cell wall is fully permeable. However, starch cannot pass through the cell membrane as the cell membrane is partially permeable.

A control has ALL FACTORS PRESENT.

Osmosis is the net movement of water molecules from a solution of higher water potential to a solution of lower water potential through a partially permeable membrane.

Diffusion is the most common type of passive transport. It is also the net movement of molecules from a region of high concentration to a region of low concentration, and it is a slow process.

Diffusion stops when molecules are dispersed evenly, with no concentration gradient, and a state of equilibrium is reached.

Excessive water intake causes an animal cell to swell and eventually bursts.

Excessive water loss causes cell to shrivel and shrink.

Diffusion takes place the fastest in gas, followed by liquid, and it takes place the slowest in solids.

Why is diffusion important?

(1)Gaseous exchange (oxygen, carbon dioxide) during respiration and photosynthesis.

(2)Excreting waste products like ammonia, water and mineral salts.

(3)Absorption of digest food into blood through walls of small intestine.

(4)Enables animals to detect food by smell.

Steps For a Starch Test:

(step 1) Boil the leaf for 5 minutes. This is to stop all enzyme action in the leaf.

(step 2) Immerse the boiled leaf in ethanol to decolourize the leaf.

(step 3) Put the decolourized leaf in hot water to soften it.

(step 4) Remove the leaf from water and drop iodine on it's surface.

(step 5)Check if the iodine turns blue-black. This will show that starch is present.

Factors that speed up diffusion:

(1)Temperature - the higher the temperature, the higher the rate of diffusion.

(2)Size of particles - small molecules are able to diffuse faster than large molecules.

(3)Thickness of barrier - thicker cell walls in plant cells, the slower the rate of diffusion. Call membranes in plants and animals are about the same thickness and permeability.

(4)Surface area - the larger the surface area, the faster diffusion can take place.

(5)Concentration gradient - The greater the gradient, the higher the rate of diffusion.

(6) State of matter - diffusion is slow in solids, faster in liquids and fastest in gases.

Diffusion in living organisms:

(1) Diffusion of digested food substances through the cells lining the small intestine and into the blood.

(2) Diffusion of oxygen, mineral salts and water from the surrounding soil into a root hair cell.

Helping Points/ Points to Consider

1) When asked to describe a cell, describe it's function and structure.

KEYWORDS :

osmosis, diffusion/diffuse, high/higher water concentration, low/lower water concentration, flaccid, turgid, homogeneously spread, partially permeable, fully permeable,

&the beauty of time is that once it starts ticking, it'll never stop.

i left what i needed to say here @1:35 PM

"Have a cup of cactus juice." That probably sounds awfully weird. However, who knows, maybe in the near future someone will start harvesting cactuses and sell cactus juice all over the world! (The price might probably drop by then..)

So, cactus juice. How does Nopalea juice sound? Well, surprisingly, Nopalea juice can help relieve pain and inflammation in your body! It is a natural anti-inflammatory and is one of the most nutrient rich cactus species known to science. Clinical studies show that the opuntia cactus is effective in fighting chronic inflammation.

It is said that Nopal cactus juice can be used to cure inflammation found in many areas of the body. Some of the areas include: muscles, gastrointestinal, cardiovascular, arterial and bones.

The fruit of the Nopalea cactus contains high amounts of calcium, magnesium and vitamin C. This cactus fruit also contains the amino acid known as taurine, is rich in flavonoids and antioxidant proteins known as betalains.

Nopal cactus fruit is low in calories, as well as sodium. In addition, it does not contain any cholesterol or saturated fat.

Nopalea cactus fruit is also high in soluble fiber. The kind that is effective in reducing cholesterol in the blood. The American Heart Association has conducted research to measure nopal cactus fruit's ability to control cholesterol levels.

The nopalea cactus can provide you with the following health benefits:

Helps you to lose weight! It curbs your appetite and blocks your body's ability to absorb fat.

Lowers your blood pressure

Lowers your cholesterol levels!

It improves your HDL / LDL ratio.
Helps to cleanse your body of harmful toxins.
Lowers your blood sugar levels.

Improves your mental focus & clarity.

So, anyone want a cup of cactus juice?

sources:

http://www.best-natural-health-supplements.com/nopalea.html

&the beauty of time is that once it starts ticking, it'll never stop.

i left what i needed to say here @1:30 PM

So what type of plants are able to survive in extreme conditions in places such as, the north and south poles and deserts? Well, depending on the place, there are some amazing plants that are able to survive, not exactly thrive, in EXTREME WEATHER CONDITIONS.

Antartica:

The extreme conditions in Antartica make it a habitat which only the hardiest survive. Very few species have been recorded on the 2% of the continent that is ice-free. They include about 150 lichens, 30 mosses, some fungi and one liverwort.

Deserts:

To survive, desert plants have adapted to the extremes of heat and aridity by using both physical and behavioral mechanisms, much like desert animals.

Plants that have adapted by altering their physical structure are called xerophytes. Xerophytes, such as cacti, usually have special means of storing and conserving water. They often have few or no leaves, which reduces transpiration.

Phreatophytes are plants that have adapted to arid environments by growing extremely long roots, allowing them to acquire moisture at or near the water table.

Other ways that plants survive:

In the desert, it's so hot, it's no wonder that hardly any plants grow there. Succulent plants such as cacti, aloes, and agaves, beat the dry heat by storing plenty of water in their roots, stems, or leaves.

When it does rain, succulents absorb as much water as they can, as quickly as possible. In the desert, water evaporates rapidly, never sinking deep into the soil. Thus, most succulents have extensive, but shallow root systems. Their roots absorb water just a half inch or so below the surface.

Succulents have evolved a number of strategies for holding onto this water. They tend to have a thick waxy coating, which helps seal in moisture.

All plants are covered by tiny pores called stomates, which allow plants to take in gasses for photosynthesis. However, these pores also allow water to be lost. Succulents have fewer stomates per cubic inch through which water can evaporate. In addition, succulents have a reduced surface area and, if they have leaves at all, they’re thick and fleshy.

Many succulent plants also have a modified way of conducting photosynthesis. Other plants open their stomates during the day to take in carbon dioxide for photosynthesis. Many succulents, however, keep their stomates closed during the heat of the day and open them in the coolness of the night to take in carbon dioxide, which they store until the next day.

Finally, because water is a scarce commodity in the desert, succulents have to protect themselves against thirsty animals. These plants protect their water supplies by being prickly like many cacti or in other cases, by being toxic, by growing in inaccessible locations, or by camouflage.

Sources:

http://indianapublicmedia.org/amomentofscience/how-plants-survive-in-the-desert/

http://www.desertusa.com/du_plantsurv.html

http://library.thinkquest.org/26442/html/life/plant.html

&the beauty of time is that once it starts ticking, it'll never stop.

i left what i needed to say here @8:45 PM

In physics, a lever (from French lever, "to raise", c.f. a levant) is a rigid object that is used with an appropriate fulcrum or pivot point to multiply the mechanical force (effort) that can be applied to another object (load). This leverage is also termed as mechanical advantage and is one example of the principle of moments. A lever is one of the six simple machines.

The Principle Of Moments states that

When a body is in an equilibrium, the sum of clockwise moments around a pivot is the same as the sum of anti-clockwise movements about the same pivot.

The Definition of Moment Of Force:

The moment of force (or torque) is the product of the force and the perpendicular distance from the pivot to the line of action of the force.

source for information: http://en.wikipedia.org/wiki/Lever

source for picture: http://www.pbs.org/wgbh/nova/teachers/activities/images/27ms_sle2treb_levers.gif

&the beauty of time is that once it starts ticking, it'll never stop.

i left what i needed to say here @4:13 PM

Stiletto heels are a fashion item that almost every woman adore and want to wear, even if it hurts their feet. It enhances their height and is also very fashionable. But is it really bad for women's feet?

Stiletto heels.

A stiletto heel, also known as a spike heel, is a long, thin heel found on some boots and shoes, usually for women. It is named after the stiletto dagger.

Stiletto heels may vary in length from 2.5cm to 25cm or more if a platform sole is used, ans are sometimes defined as having a diameter at the ground of less than 1cm.

Stiletto-style heels 5cm or shorter are called kitten heels. Not all high slim heels merit the description stiletto.

The extremely slender original Italian-style stiletto heels of the late 1950s and very early 1960s were no more than 5mm in diameter for much of their length, although the heel sometimes flared out a little at the top-piece (tip). After their demise in the mid-late 1960s, such slender heels were difficult to find until recently due to changes in the way heels were mass-produced.

A real stiletto heel has a stem of solid steel or alloy. The more usual method of mass-producing high shoe heels, i.e. moulded plastic with internal metal tube for reinforcement, does not achieve the true stiletto shape.

High heel shoes were worn by men and women courtiers. The design of stiletto heels originally came from the late Kristen S. Wagner but were not popular until the late 1950s.

As time went on, stiletto heels became known more for their erotic nature than for their ability to make height. Stiletto heels are a common fetish item. As a fashion item, their popularity was changing over time. After an initial wave of popularity in the 1950s, they reached their most refined shape in the earl y 1960s, when the toes of the shoes which bore them became slender and elongated as the stiletto heels themselves. As a result of the overall sharpness of outline, it was customary for women to refer to the whole shoe as a "stiletto", not just the heel, via synecdoche (pars pro toto).

Although they officially faded from the scene after the Beatle era began, their popularity continued at street level, and women stubbornly refused to give them up even after they could no longer readily find them in the mainstream shops. A version of the stiletto heel was reintroduced as soon as 1974 by Manolo Blahnik, who dubbed his "new" heel the Needle.

Why are stiletto heels bad for women's feet?

Stevenson's formula was primarily concerned with balance, but the awkward angles and high pressures associated with heels has been cause for concern in some circles.

For years now, orthopaedists, podiatrists and other medical sorts have been warning woman about the health risks of routinely donning high heels: bunionb, stress fractures, joint pain in the ball of the foot(because weight is shifted to the ball of your foot, rather than being distributed over the entire foot), corns and calluses, hammertoes, ingrown toenails, toenail fungus and something called "pump bumps"(enlargement of the bony area on the back of the heel).

High heels have been linked to injured leg muscles, lower back pain, and osteoarthritis in the knee, too, because when you wear heels, the foot slides forward, redistributes your weight and created those unnatural pressure points. You can pretty much kiss healthy spinal alignment goodbye.

High heels also mean your heel bones don't regularly come into contact with the ground, so the Achilles tendon can't stretch out properly while walking, and thus becomes shortened and, or tightened. Then there's a little thing called Morton's neuroma, a growth of nerve tissue in the foot--usually between the third and fourth toes-- that arises when you wear too-tight shoes, causing sharp burning pan in the ball of your foot and a stinging numbness in your toes.

The list goes on and on. In fact, thanks to high heels, the American Orthopaedic Foot & Ankle Society estimates that women account for 90% of surgeries performed each year for common foot ailments. That's about $3.5 billion annually in the US alone, according to a May 2007 article in the Washington Post.

source for picture: https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgrsQkrKuvQKWpYqq1iCz1blfi5ZyP7LAGEh4O5GkkcBDJBITU8FKGMixBetnXLOLvpDr32U8SzNxJHXyI6sLEzAG3W5-yg1K4gbHceb21F_UoerWEGoXDebyqEc8A2O9hbG8Mcrp6Blkc/s400/Stilettos2%5B1%5D.jpg

source for info: http://www.blogher.com/what-heel-why-i-hate-stilettos

http://en.wikipedia.org/wiki/Stiletto_heel

&the beauty of time is that once it starts ticking, it'll never stop.

i left what i needed to say here @9:29 PM

The word "tides" is a generic term used to define the alternating rise and fall in sea level with respect to the land, produced by the gravitational attraction of the moon and the sun. To a much smaller extent, tides also occur in large lakes, the atmosphere, and within the solid crust of the earth, acted upon by these same gravitational forces of the moon and sun. What are Lunar Tides? Tides are created because the Earth and the moon are attracted to each other, just like magnets are attracted to each other. The moon tries to pull at anything on the Earth to bring it closer. But, the Earth is able to hold onto everything except the water. Since the water is always moving, the Earth cannot hold onto it, and the moon is able to pull at it. Each day, there are two high tides and two low tides. The ocean is constantly moving from high tide to low tide, and then back to high tide. There is about 12 hours and 25 minutes between the two high tides.

Tides are the periodic rise and falling of large bodies of water. Winds and currents move the surface water causing waves. The gravitational attraction of the moon causes the oceans to bulge out in the direction of the moon. Another bulge occurs on the opposite side, since the Earth is also being pulled toward the moon (and away from the water on the far side). Ocean levels fluctuate daily as the sun, moon and earth interact. As the moon travels around the earth and as they, together, travel around the sun, the combined gravitational forces cause the world's oceans to rise and fall. Since the earth is rotating while this is happening, two tides occur each day. What are the different types of Tides When the sun and moon are aligned, there are exceptionally strong gravitational forces, causing very high and very low tides which are called spring tides, though they have nothing to do with the season. When the sun and moon are not aligned, the gravitational forces cancel each other out, and the tides are not as dramatically high and low. These are called neap tides. Spring Tides When the moon is full or new, the gravitational pull of the moon and sun are combined. At these times, the high tides are very high and the low tides are very low. This is known as a spring high tide. Spring tides are especially strong tides (they do not have anything to do with the season Spring). They occur when the Earth, the Sun, and the Moon are in a line. The gravitational forces of the Moon and the Sun both contribute to the tides. Spring tides occur during the full moon and the new moon. Neap Tides During the moon's quarter phases the sun and moon work at right angles, causing the bulges to cancel each other. The result is a smaller difference between high and low tides and is known as a neap tide. Neap tides are especially weak tides. They occur when the gravitational forces of the Moon and the Sun are perpendicular to one another (with respect to the Earth). Neap tides occur during quarter moons. The Proxigean Spring Tide It is a rare, unusually high tide. This very high tide occurs when the moon is both unusually close to the Earth (at its closest perigee, called the proxigee) and in the New Moon phase (when the Moon is between the Sun and the Earth). The proxigean spring tide occurs at most once every 1.5 years.


source: http://home.hiwaay.net/~krcool/Astro/moon/moontides/

&the beauty of time is that once it starts ticking, it'll never stop.