Which of the following is NOT one of the four primary tissue types found in the human body?

A. tRNA

B. mRNA

C. rRNA

D. DNA

Transfer RNA (tRNA) is responsible for carrying amino acids to ribosomes during protein synthesis. Each tRNA molecule has a specific anticodon that matches a codon on the messenger RNA (mRNA) molecule. The tRNA molecule binds to the mRNA codon and brings the corresponding amino acid to the ribosome, where it is added to the growing polypeptide chain.

A. kg

B. L

C. s

D. m

The unit used to indicate length is the meter (m). It is the base unit of length in the International System of Units (SI).

A. Insulin

B. Glucagon

C. Estrogen

D. Testosterone

Insulin is a hormone produced by the pancreas that plays a crucial role in regulating the levels of glucose (sugar) in the blood. After a person eats a meal, the levels of glucose in the blood rise, which stimulates the pancreas to release insulin into the bloodstream. Insulin acts on various cells in the body, particularly those in the liver, muscles, and adipose tissue, to promote the uptake, use, and storage of glucose.

Insulin helps to lower the levels of glucose in the blood by increasing the uptake of glucose by cells, stimulating the liver and muscle cells to store glucose in the form of glycogen, and inhibiting the production and release of glucose by the liver. This process is known as glucose homeostasis, and it helps to keep the levels of glucose in the blood within a normal range.

Deficiencies or abnormalities in insulin production or function can lead to a range of metabolic disorders, including type 1 and type 2 diabetes. In type 1 diabetes, the body does not produce enough insulin, while in type 2 diabetes, the body becomes resistant to the effects of insulin, leading to elevated levels of glucose in the blood.

A. renin

B. erythropoietin

C. calcitriol

D. urobilinogen

Renin is an enzyme that is produced by the kidneys and it acts to elevate blood pressure. When blood pressure falls, the kidneys secrete renin into the bloodstream ³.

A. Silent mutation

B. Nonsense mutation

C. Frameshift mutation

D. Missense mutation

A frameshift mutation is a type of genetic mutation that involves the insertion or deletion of one or more nucleotides in a DNA sequence. This can cause a shift in the reading frame of the genetic code, resulting in a change in the amino acid sequence of the resulting protein. Frameshift mutations can have significant effects on the function of the protein and can lead to genetic disorders or diseases.

A. Epithelial

B. Nervous

C. Connective

D. Exocrine glandular

Exocrine glandular is not one of the four primary tissue types found in the human body. The four primary tissue types are epithelial, nervous, connective, and muscle.

A. Linear

B. Trigonal planar

C. Bent

D. Tetrahedral

The molecular geometry of a molecule of sulphur dioxide (SO2) is bent or V-shaped. This is because of the presence of two lone pairs on the sulfur atom, which cause repulsion and distort the bond angles in the molecule.

SO2 has a central sulfur atom bonded to two oxygen atoms by double bonds. The two double bonds and the two lone pairs of electrons on sulfur result in a trigonal planar arrangement of electron pairs around the sulfur atom. However, the repulsion between the lone pairs causes the two oxygen atoms to be pulled closer together, resulting in a bent or V-shaped molecular geometry.

The bent molecular geometry of SO2 affects its properties, such as its polarity and reactivity. SO2 is a polar molecule due to the asymmetric distribution of electrons, which results in a partial positive charge on the sulfur atom and partial negative charges on the oxygen atoms. This polarity makes SO2 a good solvent and reactant in chemical reactions, as well as a contributor to air pollution and acid rain.

A. Ligaments attach skeletal muscles to bone

B. Ligaments attach two bones

C. Ligaments attach bones to tendons

D. Ligaments attach skeletal muscles to tendons

Ligaments are tough bands of fibrous tissue that connect two bones together in a joint. They provide stability and support to the joint, preventing excessive movement and helping to maintain proper alignment of the bones.

A. To produce energy for the cell

B. To store genetic information

C. To transport molecules within the cell

D. To synthesize proteins in the cell

Ribosomes are small, spherical structures found in all living cells, including bacteria, archaea, and eukaryotes. Their primary function is to synthesize proteins using the genetic information stored in the cell's DNA. Ribosomes are composed of two subunits, one large and one small, that come together during protein synthesis.

Ribosomes read the genetic information stored in mRNA (messenger RNA) and use this information to assemble amino acids in the correct order to form a protein. The ribosome moves along the mRNA, adding one amino acid at a time to the growing protein chain until it reaches the end of the mRNA and the protein is complete.

Proteins are essential for a wide variety of cellular functions, including catalyzing chemical reactions, providing structural support, and transporting molecules across cell membranes. Therefore, ribosomes play a critical role in the overall function and survival of a cell.

A. Isotonic contractions produce no movement while isometric contractions produce movement.

B. Isotonic contractions produce movement while isometric contractions produce no movement.

C. Isotonic contractions generate tension in the muscle while isometric contractions involve shortening of the muscle fibers.

D. Isotonic contractions involve contraction of individual muscle fibers while isometric contractions involve the entire muscle.

Isotonic and isometric contractions are two types of muscle contractions that differ in the amount of force produced and the movement of the muscle. In isotonic contractions, the muscle changes length and produces movement, such as lifting a weight. The force generated by the muscle remains constant throughout the movement. Isotonic contractions can be further classified as concentric contractions, in which the muscle shortens as it contracts, and eccentric contractions, in which the muscle lengthens as it contracts.

In contrast, isometric contractions occur when the muscle generates force without changing its length or producing movement. For example, holding a weight in a fixed position without moving it requires an isometric contraction. In an isometric contraction, the force generated by the muscle increases up to a maximum and then remains constant. Isometric contractions can be used to build strength and endurance in the muscle, but they do not produce movement.