ASVAB General Science Practice Test 271369

Questions 5
Topics Acidity, Blood Cells, Cell Membrane, Fermentation, Work

Study Guide

Acidity

An acid is a substance that gives up positively charged hydrogen ions (H+) when dissolved in water. A base (alkaline) gives up negatively charged hydroxide ions (OH-) when dissolved in water. pH is a scale that measures of how basic or acidic a solution is. Numbered from 0 to 14, solutions with a pH of 7 are neutral, less than 7 are acidic, more than 7 are alkaline.

Blood Cells

Blood is created in bone marrow and is made up of cells suspended in liquid plasma. Red blood cells carry oxygen, white blood cells fight infection, and platelets are cell fragments that allow blood to clot.

Cell Membrane

Animal cells are surrounded by a semipermeable membrane which allows for the transfer of water and oxygen to and from the cell. In plant cells, the cell membrane is surrounded by a somewhat rigid cell wall which provides the cell structure and support.

Fermentation

If no oxygen is present, cellular respiration is anaerobic and will result in fermentation where either lactic acid or alcohol is used instead of oxygen.

Work

Work is performed on an object when an applied force causes displacement along the same vector. Measured in joules (J) or newton-meters (Nm), work is calculated by multiplying force times displacement: \(W = \vec{F}\vec{d}\)