Biology Questions Quiz

Changes in detected frequency (ν2) of a whistle emitted by a train moving towards a stationary observer due to the relative motion of the emitting source.

Power dissipated (P1) in a cable is related to the initial length and cross-sectional area and the current (I). Cutting the cable in half (with no change in area or current), results in a different power dissipation (P2) in each half.

The force between two charged particles (A and B) is equal in magnitude and opposite in direction (Newton's Third Law).

The maximum induced electromotive force (emf) is reached in a coil with changing magnetic flux. It happens when the rate of change is the largest.

Doping a semiconductor with impurities alters the electron (ne) and hole (nh) concentrations. Doping with trivalent impurities changes these concentrations relative to the intrinsic concentrations.

The ratio of the speed of the moving train "v" to the speed of sound in air "vsound" when the Doppler effect is taken into account

If a cable with original power dissipation P1 is cut into two equal halves the power dissipation in each half P2 becomes 1/4 of P1.

The forces on two charged particles due to each other are equal in magnitude and opposite in direction.

The speed of object C changes depending on its distance from the center of object A. The provided equations (a, b, c, d) are possible mathematical models for that relationship.

If the nucleus' charge doubles, the electron's orbit radius changes. The radius is half the previous value if the principal quantum number stays the same.

0.00230 has 3 significant figures. Significant figures indicate the precision in a measurement.

A combined Carnot engine and refrigerator system, operating between specific temperatures and extracting/releasing heat; the total heat released into the atmosphere in one cycle is 2000 kJ.

Significant figures indicate the degree of accuracy in a measurement.

It represents an energy level in the atomic model. Its value is maintained across different scenarios (within the context of the provided model).

A fundamental characteristic of an electron's motion around an atom's nucleus.

A Carnot engine's efficiency is determined by the temperatures of its heat reservoirs, with maximum efficiency at higher temperatures (for a given temperature difference).

A machine extracting heat from lower temperature source and expelling into higher temperature atmosphere.

A function is increasing if its value increases as the input increases, and decreasing if its value decreases as the input increases.

A function is differentiable at a point if its derivative exists at that point. This means the function has a smooth, continuous slope at that point.

The total distance traveled divided by the total time taken.

The ratio of an object's density to the density of the fluid it's in determines whether it floats or sinks. A floating object displaces a volume of fluid equal to its own weight.

The ratio of the image size to the object size. A positive magnification means an upright image, while a negative magnification means an inverted image.

The apparent change in frequency of a wave (e.g., sound) when the source of the wave and the observer are moving relative to each other.

A converging lens that can form both real and virtual images depending on the object's position.

A real image can be projected onto a screen, while a virtual image cannot. Real images are formed by the actual intersection of light rays, while virtual images are formed by the apparent intersection of the extensions of light rays.

A state where allele and genotype frequencies in a population remain constant over generations, assuming no evolutionary influences.

A genetic disorder caused by a recessive allele located on an autosome (non-sex chromosome), where two copies of the recessive allele are needed for the disease to manifest.

Having two different alleles for a particular gene.

The process of inserting a specific DNA fragment into a vector (e.g., plasmid) for replication and amplification.

Enzymes that recognize specific DNA sequences and cut them at those sites, allowing for manipulation and cloning of DNA fragments.

A technique used to separate DNA fragments based on size by applying an electric field to a gel matrix.

A pattern of inheritance where a single copy of a dominant allele is sufficient for the trait to be expressed.

A pattern of inheritance where a recessive allele located on the X chromosome is expressed in males who inherit it, but females need two copies for expression.

The process where atmospheric nitrogen gas (N2) is converted into a usable form by certain bacteria, primarily in the roots of legumes. This conversion involves the enzyme nitrogenase, which uses energy from ATP to break the strong triple bond in N2 and form ammonia (NH3).

Nitrogenase, the enzyme responsible for nitrogen fixation, requires a specific environment to function optimally. It is highly sensitive to oxygen, which can actually inhibit its activity. Therefore, nitrogen fixation typically occurs in anaerobic conditions, often within specialized structures called nodules on legume roots.

Plants produce amides, like asparagine and glutamine, as a result of nitrogen fixation and metabolism. These amides are transported through the phloem throughout the plant body, providing nitrogen to various tissues and organs for growth and development.

Genetic diversity refers to the variety of genes within a species or population. This variation in genes can lead to differences in traits and characteristics, making a species more resilient to environmental changes and diseases.

An example of genetic diversity is the variation in the potency and concentration of reserpine, a medicinal compound produced by the plant Rauwolfia vomitoria. This variation is due to differences in the genes responsible for producing reserpine.

During translation, when the ribosome encounters a stop codon in the mRNA, it signals the termination of protein synthesis. A special protein called a release factor binds to the stop codon, causing the ribosome to detach from the mRNA and release the newly synthesized polypeptide chain.

Before a messenger RNA (mRNA) molecule can be translated into a protein, it needs to undergo splicing. This process involves removing non-coding regions (introns) from the pre-mRNA (hnRNA) and joining the coding regions (exons) together. This splicing is essential for generating a functional mRNA that can be read by the ribosome.

Competitive inhibitors are molecules that bind to the active site of an enzyme, blocking the substrate from binding. They compete with the substrate for the same binding site, slowing down the enzyme's catalytic activity.

The set of all possible points where the centers of circles can be located if they pass through the origin with a fixed radius.

The number of times a parabola intersects a pair of lines determined by the equation y² = 1. The answer depends on the value of α in the parabola's equation, which affects the parabola's position and orientation.

The cosines of the angles that a line makes with the positive x, y, and z axes. They represent the direction of the line in 3D space.

Finding the total number of whole numbers that divide evenly into a given number. This relies on factoring the number into its prime factors.

The standard deviation of a data set after incorporating an additional data point that keeps the mean unchanged. The new standard deviation is affected by the original standard deviation and the number of data points.

The probability of an event happening given that another event has already occurred. It's calculated by dividing the probability of both events occurring by the probability of the second event occurring.

Adding a data point to a set can maintain the original mean. This means the new data point must balance the existing data.

The standard deviation measures how much data points deviate from the mean. Adding data points can influence this deviation.