General Science and Technology Fundamentals

The HTC HD7 was a Windows Phone 7 device running Windows Mobile 7 (not the older Windows Mobile 6.x). It did not use Symbian, Android, or Java.

The Samsung Galaxy S (i9000) ran on Android 2.1 Eclair (upgradable to later versions). It did not use Windows Mobile, Bada (Samsung's proprietary OS was used on Wave series), or any other OS.

The Samsung Galaxy 3 (i5800) was launched with Android 2.1 Eclair out of the box in 2010. It later received an upgrade to Android 2.2 Froyo, but the initial version was v2.1.

The Samsung Wave 2 ran Samsung's Bada operating system, not Android. Bada was Samsung's proprietary smartphone platform before they fully committed to Android for their Galaxy line.

The Sony Ericsson Vivaz ran on Symbian OS v9.4, not Android. Symbian was the dominant smartphone operating system before Android and iOS became popular.

Android was developed by Android Inc. and acquired by Google in 2005. IBM has never been involved in Android's development or ownership; it has always been a Google product.

Common table salt is sodium chloride (NaCl). Baking soda is sodium bicarbonate (NaHCO3), also known as sodium hydrogen carbonate. Option D is correct.

The ozone hole refers to the thinning of the ozone layer in the stratosphere, particularly over Antarctica. It is not an actual hole but a decrease in thickness of the ozone layer in the stratosphere. Option C is correct.

Pollination is the transfer of pollen grains from the anther (male part) to the stigma (female part) of a flower. This is the first step in plant fertilization. Option B describes pollen germination, which occurs after pollination. Option C describes fertilization itself. Option D describes pollinator behavior, not the pollination process.

Plants absorb water and dissolved minerals (nitrogen, phosphorus, potassium, etc.) from soil through their roots. While atmospheric CO2 provides carbon and light provides energy for photosynthesis, soil is the primary source of essential nutrients required for growth and development.

Active transport is the movement of molecules across a cell membrane from a region of lower concentration to a region of higher concentration, requiring energy (ATP). This is the opposite of passive processes like osmosis and diffusion, which move substances down their concentration gradient without energy input.

Photosynthesis occurs primarily in leaves and other chloroplast-containing parts of plants because chloroplasts contain chlorophyll, which captures light energy. Options B and C contain stems/roots which lack chloroplasts or have minimal photosynthetic capacity. Option D includes bark which does not photosynthesize.

Plants synthesize proteins by linking amino acids together through peptide bonds. Amino acids are the building blocks of all proteins. Starch is a carbohydrate storage molecule, sugar provides energy, and fatty acids are used for lipid synthesis - none are direct protein precursors.

Plants absorb nitrates (NO3-) from soil through their roots and reduce them to form free nitrogen (N2) as part of their metabolic processes. They do not convert nitrates to urea (animal waste), ammonia (intermediate form), or directly to proteins (which are built from amino acids).

Bones provide attachment points for muscles (A), protect vital organs like the brain and heart (B), and produce blood cells in bone marrow (D). However, hormone secretion for calcium regulation is done by the parathyroid gland and calcitonin from the thyroid gland, not by bones themselves - though bone tissue responds to these hormones.

The decibel (dB) is the standard unit for measuring sound intensity and amplitude. Coulomb measures electric charge. 'Hum' is not a standard unit. 'Cycles' refers to frequency (Hz), not amplitude. Sound amplitude determines loudness and is measured logarithmically in decibels.

A falling barometer indicates decreasing atmospheric pressure, which typically signals approaching rain or stormy weather. Low pressure systems are associated with cloud formation and precipitation. High pressure (rising barometer) usually brings fair weather. Snow (A) requires cold plus low pressure, but the pressure drop alone predicts rain/storm conditions.

The decibel (dB) measures the intensity or loudness of sound. Speed of light is measured in m/s. Radio wave frequency is measured in Hertz. Heat intensity can be measured in temperature units or calories/watts, not decibels. Decibels can also measure other logarithmic ratios (like signal power), but sound intensity is the most common educational context.

One fathom equals exactly 6 feet (approximately 1.83 meters). It is a nautical unit used to measure water depth. Option B is wrong because 6 meters is much larger (about 19.7 feet). Option C (60 feet) is 10 fathoms. Option D (100 cm) is only about 3.28 feet.