What is a primer in DNA sequencing?

Bacteria can perform photosynthesis while archaea cannot. Many types of bacteria can generate oxygen from sunlight through photosynthesis, while archaea cannot perform this process.

Choice A is incorrect because neither bacteria nor archaea have a true nucleus. Both are prokaryotic organisms. Choice B is incorrect because archaea reproduce by fission, fragmentation, or budding, while bacteria can produce spores and divide sexually or asexually. Choice D is incorrect because archaeal and bacterial flagella are constructed differently.

Ionization is the process in which an atom loses or gains electrons to form an ion.

An ion is an atom or molecule that has a net electrical charge due to the loss or gain of one or more electrons.

Choice B is not the best answer because oxidation refers to the loss of electrons from an atom or molecule.

Choice C is not the best answer because reduction refers to the gain of electrons by an atom or molecule.

Choice D is not the best answer because isotopic decay refers to the process in which an unstable atomic nucleus loses energy by emitting radiation

The correct answer is choice A.

Increased respiration rate to remove excess CO2.

The body regulates blood pH through several mechanisms, including chemical buffers, the respiratory system, and the urinary system.

The respiratory system can adjust blood pH by changing the rate of respiration to remove or retain CO2.

When there is excess acid in the blood, the respiratory rate increases to remove more CO2, which helps to raise blood pH.

Choice B is incorrect because decreasing the respiration rate would retain CO2, which would lower blood pH.

Choice C is incorrect because increased water intake would not directly affect blood pH levels.

Choice D is incorrect because decreased water intake would not directly affect blood pH levels.

A primer is a short single-stranded DNA fragment used in certain laboratory techniques, such as the polymerase chain reaction (PCR).

In the PCR method, a pair of primers hybridizes with the sample DNA and defines the region that will be amplified.

Choice A) A short piece of double-stranded DNA that binds to the template DNA and acts as a “starter” for the polymerase is incorrect because primers are single-stranded, not double-stranded.

Choice B) A short piece of double-stranded DNA that binds to the primer and acts as a “starter” for the template is incorrect because it does not make sense for a primer to bind to itself.

Choice D) A short piece of single-stranded DNA that binds to the polymerase and acts as a “starter” for the template is incorrect because primers bind to the template DNA, not to the polymerase.

Note:DNA primers are used instead of RNA primers in DNA sequencing and PCR because DNA is more stable, specific, and compatible with the enzymes and processes involved in these techniques.

The correct answer is choice A. Keratin.

Keratin is a fibrous protein that provides strength and protection to the body, particularly in the skin, hair, and nails.

It is found in epithelial tissue, which covers the body’s surface and lines its internal organs and cavities.

Choice B.

Collagen is incorrect because collagen is a fibrous protein that provides strength and support to connective tissues such as tendons, ligaments, and cartilage.

Choice C.

Elastin is incorrect because elastin is a protein that provides elasticity to tissues such as skin and blood vessels.

Choice D.

Actin is incorrect because actin is a protein that plays a role in muscle contraction and cell movement.

The correct answer is choice A.

An increase in viscosity of a fluid results in a decrease in mobility of particles.

Viscosity is the resistance of a fluid to a change in shape or movement of neighboring portions relative to one another.

It denotes opposition to flow and may be thought of as internal friction between the molecules.

Choice B is incorrect because an increase in viscosity does not affect the density of a fluid.

Choice C is incorrect because an increase in viscosity results in a decrease, not an increase, in flow rate.

Choice D is incorrect because an increase in viscosity does not affect the pressure of a fluid.

Protons contribute to the positive charge of an atom.

Protons are subatomic particles with a positive charge found in the nucleus of an atom.

Choice B is incorrect because neutrons are neutral and do not have a charge. Choice C is incorrect because electrons have a negative charge.

Choice D is incorrect because nucleons refer to both protons and neutrons, but only protons contribute to the positive charge of an atom.

Glycogen is the storage form of glucose in the human body.

It is a polysaccharide that is stored primarily in the liver and muscle tissue and can be broken down into glucose when the body needs energy.

Choice A is incorrect because starch is a storage form of glucose in plants, not in the human body.

Choice C is incorrect because fructose is a simple sugar, not a storage form of glucose.

Choice D is incorrect because cellulose is a structural carbohydrate found in plant cell walls, not a storage form of glucose in the human body.

The correct answer is choice A. Hydrogen bonds.

Hydrogen bonds are responsible for the unique properties of water and play a crucial role in the structure of DNA and proteins.

Hydrogen bonds are weak electrostatic attractions between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom.

Choice B.

Covalent bonds is incorrect because covalent bonds are strong chemical bonds formed by the sharing of electrons between two atoms.

Choice C.

Ionic bonds is incorrect because ionic bonds are chemical bonds formed by the transfer of electrons from one atom to another, resulting in the formation of ions.

Choice D.

Van der Waals forces is incorrect because Van der Waals forces are weak intermolecular forces that arise from temporary dipoles induced in atoms or molecules.

The correct answer is choice C. Substitution.

A substitution mutation is a type of point mutation where one base in the DNA sequence is replaced by another base.

Choice A is incorrect because a deletion mutation occurs when one or more bases are removed from the DNA sequence.

Choice B is incorrect because an insertion mutation occurs when one or more bases are added to the DNA sequence.

Choice D is incorrect because an inversion mutation occurs when a segment of DNA is reversed within the chromosome.