What is the name of the hormone that regulates blood sugar levels in the human body?

• Frontal Plane (Coronal Plane) → Divides the body into front (anterior) and back (posterior) halves. ❌
• Transverse Plane → A horizontal plane that divides the body into upper (superior) and lower (inferior) halves. ✅
• Sagittal Plane → Divides the body into left and right halves. ❌
• Coronal Plane → Another name for the Frontal Plane, which divides the body into front and back. ❌

Chemical properties are characteristics of a substance that describe its ability to undergo a chemical change or reaction with another substance. Reactivity with acid is a chemical property because it describes how a substance will react with an acid to produce a new substance.

Density, melting point, and boiling point are physical properties that describe how a substance behaves under certain conditions but do not involve a chemical change or reaction.

Carbohydrates are one of the main types of biomolecules and are composed of monomers called monosaccharides. Monosaccharides are simple sugars that cannot be further broken down into simpler sugars. They are usually composed of 3 to 7 carbon atoms and have a general formula of (CH2O)n, where n is a number between 3 and 7. Examples of monosaccharides include glucose, fructose, and galactose.

When two monosaccharides are joined together by a glycosidic bond, they form a disaccharide. Disaccharides are composed of two simple sugars and can be broken down into their constituent monosaccharides by hydrolysis. Examples of disaccharides include sucrose, lactose, and maltose.

Option a) is incorrect because it describes the composition of a disaccharide, not a monosaccharide. Option

c) is incorrect because both monosaccharides and disaccharides can be found in both plants and animals.

Option d) is incorrect because both monosaccharides and disaccharides can be used for energy storage and

structural purposes, depending on their specific structure and function in the organism.

• A. Sarcoplasmic Reticulum → A specialized endoplasmic reticulum in muscle cells that stores and releases calcium for muscle contraction. ❌
• B. Muscle Fiber → Another name for a muscle cell, which is a long, cylindrical, multinucleated cell that makes up muscle tissue. ✅
• C. Sarcolemma → The cell membrane of a muscle fiber, which surrounds the muscle cell. ❌
• D. Myofilament → Protein structures (actin and myosin) within a muscle fiber that are responsible for contraction. ❌

The vertebral column, also known as the spine or spinal column, is a series of bones called vertebrae that extend from the skull to the pelvis. It provides support for the body and protects the spinal cord. The five regions of the vertebral column, starting from the top and moving downwards, are:

1. Cervical: This region is made up of seven vertebrae and is located in the neck. The first two cervical vertebrae, the atlas and the axis, are specialized to allow for head movement.

2. Thoracic: This region is made up of twelve vertebrae and is located in the upper and middle back. The thoracic vertebrae are larger than the cervical vertebrae and articulate with the ribs.

3. Lumbar: This region is made up of five vertebrae and is located in the lower back. The lumbar vertebrae are the largest and strongest of the vertebrae.

4. Sacral: This region is made up of five fused vertebrae and is located in the pelvis. The sacrum forms the posterior wall of the pelvis and articulates with the hip bones.

5. Coccygeal: This region is made up of four fused vertebrae and is located at the base of the vertebral column. The coccyx, or tailbone, provides atachment points for muscles and ligaments.

The three major pairs of salivary glands are the parod glands, sublingual glands, and submandibular glands. The parotid glands are located just in front of your ears. The sublingual glands are below either side of your tongue, under the floor of your mouth. The submandibular glands are located below your jaw ¹.

A physical change is a change that affects the physical properties of a substance, but does not change its chemical identity. Physical changes include changes in state, such as melting or boiling, changes in shape or size, and changes in phase, such as the dissolution of a solid in a liquid.

A chemical change, on the other hand, is a change that results in the formation of new substances with different chemical properties. Chemical changes involve the breaking of chemical bonds between atoms and the formation of new bonds to create new compounds. Chemical changes are usually accompanied by a change in color, the formation of a gas or a solid, or the release or absorption of energy.

Overall, the main difference between a physical change and a chemical change is that a physical change only affects the physical properties of a substance while a chemical change results in the formation of new substances with different chemical properties.

Note:Choice B is partially cirrect since physical changes can involve changes in the state of matter (e.g., ice melting into water), but it's not the main characteristic. A chemical change typically involves the change of one substance into another with different chemical properties.

The main difference between a solid and a liquid is their physical state and the way their particles are arranged. In a solid, the particles are tightly packed together and have a fixed position, which gives the solid a definite shape and volume. Solids are also characterized by their high density, low compressibility, and high thermal conductivity.

In contrast, the particles in a liquid are more loosely packed and can move around each other, which allows the liquid to take the shape of its container. Liquids have a definite volume but no fixed shape, which means they can be poured or spilled. Liquids also have a lower density than solids, are more compressible than solids, and have lower thermal conductivity than solids.

Option b) is incorrect because it describes the properties of a gas, not a liquid. Option c) is incorrect because solids and liquids have different physical properties. Option d) is incorrect because it describes the properties of a gas, not a liquid or a solid.

Muscle contraction is a complex process that involves the interaction between actin and myosin filaments in the muscle fibers. The sliding of these filaments is initiated by the release of calcium ions from the sarcoplasmic reticulum, a specialized organelle in muscle cells. The calcium ions bind to the protein troponin, which causes a conformational change in the troponin-tropomyosin complex, exposing the myosin-binding sites on actin. This allows the myosin heads to bind to actin, forming cross-bridges that pull the actin filaments towards the center of the sarcomere, resulting in muscle contraction.

Option a) is incorrect because calcium does not bind to tropomyosin directly, but rather binds to the protein troponin, causing a conformational change in the troponin-tropomyosin complex. Option c) is incorrect because calcium does not activate motor neurons, but rather is released from the sarcoplasmic reticulum in response to an action potential that travels down the motor neuron to the neuromuscular junction. Option d) is incorrect because calcium is required for muscle contraction, not relaxation. The relaxation of muscles after contraction is due to the active transport of calcium ions back into the sarcoplasmic reticulum, which allows the troponin-tropomyosin complex to return to its resting conformation, blocking the myosin-binding sites on actin and ending the cross-bridge cycle.

• The number of protons in an atom is equal to its atomic number.
• The periodic table shows that phosphorus (P) has an atomic number of 15.
• This means every phosphorus atom has 15 protons in its nucleus.

Analysis of Other Options:

• A. 30 → This is close to the atomic mass (30.97), but the atomic mass is not the same as the number of protons. ❌
• B. 16 → This is incorrect; sulfur (S) has an atomic number of 16, not phosphorus. ❌
• D. 31 → This is rounded from the atomic mass (30.97), but atomic mass ≠ number of protons. ❌