ATI TEAS 7 Science Exam Comprehensive Study Guide

Atomic Structure and Chemical Principles

• Isotopic Characteristics of Carbon-12:     - Carbon possesses an atomic number of $6$.     - The isotope $C-12$ is characterized by having exactly $6$ protons and $6$ neutrons within its nucleus.     - In a neutral atom of $C-12$, there are also $6$ electrons to balance the $6$ protons.

• Atomic Radius Trends:     - Among the elements Germanium ($Ge$), Carbon ($C$), Tin ($Sn$), and Silicon ($Si$), Carbon ($C$) possesses the smallest atomic radius.

• Chemical Periodicity and Formulas:     - When an ionic salt dissolves in water to form the ions Carbonate ($CO_3$) and Potassium ($K^+$), the resulting chemical formula for the salt is $K_2CO_3$.

• States of Matter and Phase Changes:     - Sublimation: This is the specific process by which a solid, such as solid carbon dioxide (dry ice), turns directly into carbon dioxide gas without passing through a liquid phase.     - Gas Dynamics: An equal mass of gas can completely fill containers of varying sizes, such as a $100\,dm^3$ or $500\,dm^3$ container, due to its ability to expand and occupy the available volume.

• Properties and Behavior of Water:     - Solubility: A primary property of water is its ability to dissolve polar ionic compounds.     - Meniscus Formation: Water forms a concave (downward-curving) meniscus in a glass beaker because the adhesive forces between the water molecules and the glass are greater than the cohesive forces between the water molecules themselves.     - Density: Solid water (ice) is notably less dense than liquid water, which is why ice floats.

• Measurement Units:     - The unit used to indicate mass among common laboratory measurements is the milligram ($mg$).     - Units such as $cm^3$ and $ml$ are used for volume, while $Irm$ is not a standard unit for mass.

Cell Biology and Molecular Genetics

• Cellular Structures and Comparison:     - The cell membrane is a structure present in both prokaryotic and eukaryotic cells.     - Structures such as the Endoplasmic Reticulum, Chloroplasts, and the Golgi Apparatus are membrane-bound organelles exclusive to eukaryotic cells.

• Genetic Material and Proteins:     - Histones: These are specific proteins that are intimately associated with DNA, aiding in the packaging and structural organization of chromatin.     - DNA Complementary Base Pairing: If a segment of DNA reads $5'\text{-AGCTAGCGT-}3'$, the complementary strand will read $3'\text{-TCGATCGCA-}5'$ (following the rule that Adenine pairs with Thymine and Cytosine pairs with Guanine).

• Biomolecules:     - Carbohydrates are complex molecules composed of simpler subunits known as monosaccharides.

• Cellular Transport Mechanisms:     - Active Transport: This involves the movement of substances across a cell membrane against their concentration gradient, requiring energy. An example includes the sodium-potassium pump or specific movements of sodium and potassium.     - Passive Transport (Osmosis): When a cell is placed in a hypertonic solution, there is a net flow of water out of the cell toward the higher solute concentration.     - Aquaporins: These are specialized channels in kidney cells that facilitate the movement of water to help concentrate urine.

• Inheritance and Phenotypes:     - Mutations that occur in ovarian cells (germline cells) can be inherited by offspring, whereas mutations in somatic cells (endocrine, neural, muscle) cannot.     - The seasonal change in the coat color of an arctic fox from brown in summer to white in winter represents a change in the fox's phenotype (physical expression), while the genotype (genetic makeup) remains unchanged.

Human Anatomy and Physiology

• Body Cavities:     - The ventral cavity is a major body cavity that is further subdivided into the thoracic cavity and the abdominopelvic cavity.

• The Cardiovascular System:     - Vessels: The superior vena cava is the vessel responsible for carrying deoxygenated blood from the upper body to the right atrium of the heart.     - Pulmonary Circuit: The pulmonary vein is a critical component of the pulmonary circuit, carrying oxygenated blood from the lungs back to the heart.     - Path of Blood Flow: Starting from the superior vena cava, blood flows through the Right Atrium → Right Ventricle → Pulmonary Valve → Pulmonary Artery → Lungs.

• The Respiratory System:     - Inhalation Mechanics: During inhalation, the diaphragm moves downwards to increase thoracic volume, and air moves from areas of high pressure (atmosphere) to lower pressure (lungs).     - Gas Exchange: Carbon dioxide moves from the blood into the alveoli primarily through diffusion down a concentration gradient.     - Anatomical Protection: The epiglottis is a flap of cartilage that prevents food from entering the trachea during swallowing.     - Tissue Origin: The lungs develop from the same origin tissue as the gastrointestinal system.

• The Nervous and Endocrine Systems:     - Hypothalamus: This part of the central nervous system releases chemicals (releasing hormones) that regulate the activity of the pituitary gland.     - Paralysis: Permanent damage to the nervous tissue within the spinal cord is the direct cause of paralysis.     - Hormone Action: Hydrophilic hormones activate target cells by binding to cell-surface receptors, as they cannot pass through the lipid bilayer of the plasma membrane.

• The Musculoskeletal System:     - Tendons: These structures function to attach skeletal muscles to bones.     - Ligaments: These structures typically connect bone to bone.     - Muscle Contraction: The shortening of a sarcomere in skeletal muscle is directly due to the interaction between myosin and actin filaments. Specifically, myosin is responsible for forming cross-bridges with actin molecules.

• The Digestive and Integumentary Systems:     - Enzymatic Action: Pancreatic amylase is the secretion responsible for digesting starch into disaccharides.     - Skin Layers: The dermis is the layer of skin containing functional structures such as glands and hair follicles.     - Excretion: Sweat glands excrete substances including water and urea, the latter being a byproduct of protein breakdown and ammonia formation.     - Metabolic Waste: The term "excretion" refers specifically to the removal of metabolic waste from the body.

• Reproductive Physiology:     - A vasectomy causes infertility because it blocks the movement of sperm from the epididymis into the urethra by cutting the vas deferens.

Immunology and Microbiology

• Innate and Adaptive Immunity:     - Adaptive Immunity: This is defined as a highly specific response to the unique traits of specific pathogens.     - Active Immunity: This refers to the lifelong protection gained after exposure to a virus, such as chickenpox, where the body produces its own antibodies and memory cells.     - Barriers: Mucous membranes and secretions represent the body's initial barrier defenses.

• Virology (HIV/AIDS):     - The AIDS virus (HIV) is an RNA virus. It uses the enzyme reverse transcriptase to convert its viral RNA into DNA, which can then be inserted into the host T-cell's DNA.

Scientific Method and Research

• Experimental Design and Analysis:     - Hypothesis: A scientist's prediction (e.g., that germinating beans use more oxygen than non-germinating beans) is formally termed a hypothesis.     - Correlational Study Weakness: A significant limitation of a correlational study is its inability to determine causation between variables.     - Variables in Photosynthesis Experiment: In an experiment testing Arabidopsis plants under UV, IR, and white light:         - IR-treated plants were scorched.         - UV-treated plants wilted.         - White light plants grew normally.         - A potential critique of this specific setup is that three plants per group do not provide sufficient replications to draw a definitive conclusion.

• Buffer Systems:     - The carbonic acid-bicarbonate ion buffer system maintains blood pH via the following equilibrium: $CO_2 + H_2O \rightleftharpoons H_2CO_3 \rightleftharpoons HCO_3^- + H^+$.     - When there are excessive $H^+$ ions (acidosis), the reaction that takes place to buffer the acidity is $HCO_3^- + H^+ \rightarrow H_2CO_3$.

• Mathematics and Data Representation:     - Volume Calculation: To find how many times larger the volume of a $4\,mm$ cube is compared to a $2\,mm$ cube:         - Volume of $4\,mm$ cube: $4^3 = 64\,mm^3$         - Volume of $2\,mm$ cube: $2^3 = 8\,mm^3$         - Ratio: $\frac{64}{8} = 8$         - The larger cube is $8$ times the volume of the smaller cube.     - Graphs:         - A bar graph is ideal for comparing the effectiveness of various medications against a placebo across large amounts of patient data.         - High-resolution annual photographs of Earth from space are most useful for analyzing long-term environmental changes like deforestation in the rainforest.