Answer: D) All of the above Explanation: A computer system consists of a computer case, a power supply unit, a motherboard, a central processing unit (CPU), main memory, and a hard disk drive. Input devices include a keyboard, mouse, microphone, video camera, and image scanner. Output devices include a monitor, speakers, and a printer.

Answer: B) FALSE Explanation: The given statement that all cells divide at the same rate is FALSE.   No, all cells do not divide at the same rate. Cells that require frequent replenishing, such as skin or intestinal cells, may only take roughly twelve hours to complete a cell cycle. Other cells, such as liver cells, remain in a resting state (interphase) for up to a year before undergoing division.

Adolf Hitler was involved in the Holocaust. The Holocaust, also referred to as the Shoah, was a genocide during World War II in which Nazi Germany, aided by its collaborators, systematically murdered approximately 6 million European Jews, around two-thirds of the Jewish population of Europe, between 1941 and 1945.

Answer: C) iron Explanation: A magnetic domain is a region within a magnetic material in which the magnetization is in a uniform direction. This means that the individual magnetic moments of the atoms are aligned with one another and they point in the same direction.

Answer: B) the horizontal sum of individual demand curves Explanation:

Answer: A) 15 min Explanation: Beavers Can Hold Their Breath for 15 Minutes Underwater. The behavior of beavers means that they need to be able to remain underwater for several minutes at a time.

Answer: B) Metaphase Explanation: A chromatid is one copy of a newly copied chromosome which is still joined to the original chromosome by a single centromere. The two identical copies—each forming one half of the replicated chromosome are called chromatids. Chromonema is the fibre-like structure in prophase in the primary stage of DNA condensation. In metaphase, they are called chromatids.

Answer: C) Synaptic cleft Explanation: A neuron or nerve cell is a cell that carries electrical impulses. Neurons are the basic units of the nervous system and its most important part is the brain. Every neuron is made of a cell body (also called a soma), dendrites and an axon. Dendrites and axons are nerve fibres.   The gap between two communicating neurons is termed Synaptic cleft.