A botanist observes that the leaves of tomato plant A are beginning to wrinkle and mottle. Plant B, which sits directly next to plant A, appears healthy. What experiment might help determine whether virus X is causing plant A’s leaves to wrinkle and mottle?

If heat is added to a liquid which of the following occurs?

What is the number of electrons present in H+?

Blood types are differentiated according to which of two antigen types (A or B) the blood contains. When blood of one type is introduced into blood of a different type, antibodies (either anti-A anti-B) that are present in the one type but not the other will react with the foreign antigens, resulting in dangerous clumping of the blood.

Which would probably be a dangerous blood transfusion?

A 4.5-volt battery sends an electrical current through a wire to a resistor. Resistance is measured in ohms (Ω). From the resistor, the current travels through another wire to an ammeter that measures the current in ampere units. The relationship among voltage (V), current (A), and resistance (Ω) is as follows:
Ω = V/A
If the ammeter measures the current at 0.3 amperes, what is the amount of the resistance?

Below are some terms associated with the functioning of neurons, which are the nerve cells that transmit information throughout the body.

Interneurons: Neurons of the peripheral nervous system; send signals back and forth between the brain or spinal cord and the limbs and sense organs
Sensory neurons: Neurons that transmit messages to the brain and the spinal cord from the sense organs
Motor neurons: Neurons that carry commands from the brain and spinal cord to the muscles and glands
Chemical exchange: the means by which neurons send and receive electrical signals associated with smell and taste
Mechanical stimulus: the means by which neurons send and receive electrical signals associated with sight, sound, and touch

What best explains why someone might feel no heat when poking a hot coal with an extended finger?

An atom with just one electron in its outer shell will seek to shed that electron so that its outer shell is complete. An atom whose outer shell is missing just one electron will seek to complete that shell by acquiring an electron from another atom.
An ion is an atom that has become either negatively or positively charged. How can an atom become a negative ion?

Three different systems for measuring temperature are shown. The Kelvin scale was developed more recently than the other two, mainly for use in science laboratories. Why was the Kelvin scale probably adopted? The Kelvin scale was probably adopted because the Celsius and Fahrenheit scales

All light waves travel at the same speed (rate of motion). Why can’t we see gamma rays?

How does the Earth stay the same while these tectonic plates are continuously moving into and out of each other?

An object accelerates (changes its speed) only if the forces acting on it in one direction are greater than the forces in the opposite direction, All of the following objects will accelerate EXCEPT

Different colors of light correspond to different wavelengths.Wavelengths are often quoted in nanometers (nm). The wavelengths of the visible part of the spectrum are shown in the diagram below.
According to the diagram, blue-green light would most likely have a wavelength of

If heat is added to a liquid which of the following occurs?

The mechanical advantage of using the type of machine shown can be demonstrated by the use of which of the following tools?

When a person faces sudden stress, he or she may experience an “adrenaline rush,” during which the adrenal glands secrete hormones that work to increase blood-sugar levels and increase oxygen consumption and blood flow in skeletal muscles, while decreasing oxygen consumption and blood flow in smooth muscles.

Why do these internal bodily responses make sense?
They help a person to

Genetically modified crops and livestock offer the possibility of greater yield and food quality, reductions in pesticide use, and higher profits for agricultural businesses. They are viewed by some as a way to help reduce world hunger by increasing food production and reducing losses to pests and varying environmental conditions. Each year, industrial agriculture relies more heavily on genetically modified crops. There are some concerns about our increasing use of genetically modified crops and livestock, including their safety for human consumption and their effects on the environment.

Based on the passage above, if genetically modified crops were to be banned, what could be the largest negative impact to humans?

Battery companies make impressive claims about how long their batteries will last. A student decided to test the running time of different batteries to determine which battery lasts the longest. The student tested 6 different batteries, 4 brand name and 2 generic, using flashlights. The results show that the battery referred to as Name Brand A lasted the longest, with 101 hours of runtime:

Flashlight	Battery	Runtime in hours
Gearlight Super Light	Name Brand A	101
SureFire	Name Brand B	99
Maglight	Name Brand C	80
Bright Star	Name Brand D	75
SureFire	Generic A	30
Bright Star	Generic B	29

It could be argued that this experiment was not set up using proper experimental protocol. What would need to change in the experiment for the results to be valid?

The Ionic Product of Water, \({K_{\rm{w}}}\), is the equilibrium constant for the reaction in which water undergoes an acid-base reaction with itself.
\({K_{\rm{w}}} = \left[ {{H_3}{O^ + }_{(aq)}} \right]\left[ {O{H^ - }_{(aq)}} \right] = {10^{ - 14}}at25{}^oC\)
The value of K_w increases almost 75 times when temperature is increased from 0°C to 100°C .
According to the above equation, what type of behavior is shown by water?

If heat is added to a liquid which of the following occurs?

What is the correct order?

Enzymes are proteins, and their functions are determined by their complex structure. The way enzymes work can also be shown by considering the energy changes that take place during a chemical reaction. We shall consider a reaction where the product has a lower energy than the substrate, so the substrate naturally turns into product (in other words the equilibrium lies in the direction of the product). Before it can change into product, the substrate must overcome an ‘energy barrier’ called the activation energy (EA). The larger the activation energy, the slower the reaction will be because only a few substrate molecules will by chance have sufficient energy to overcome the activation energy barrier.
How do enzymes affect the activation energy of the reactants?

As temperature rises, solids generally become more soluble in water, but gases become less soluble. If a soft drink contains high concentrations of sugar and carbon dioxide, which of the following may be expected to happen if it is cooled down?
A .Sugar may precipitate out.
B .Gas bubbles may form and produce foam.
C .Water may evaporate rapidly.

The Florida panther once roamed widely in the southeastern United States. The number of Florida panthers was drastically reduced due to loss of habitat, hunting, and even collisions with automobiles. By the 1970s, the estimated number of Florida panthers had shrunk to only six.
Which of the following describes the most likely next stage in this situation?

Which of the following is the most common result of prolonged excessive alcohol consumption?

Cyclooxygenase-2 (COX-2) is an enzyme vital to the production of the prostaglandins, but also contributes to the inflammation of joints in medical conditions such as arthritis. New medications that block the production of prostaglandins by COX-2 enzymes and thereby relieve the symptoms of arthritis are a type of