Test Assessing Secondary Completion (TASC) Science Syllabus

Write the overall chemical equation for photosynthesis.

$\ce{6CO2 + 6H2O ->[\text{light}] C6H12O6 + 6O2}$

Write the overall chemical equation for cellular respiration.

$\ce{C6H12O6 + 6O2 -> 6CO2 + 6H2O + energy(ATP)}$

What molecule is the primary energy currency of the cell?

ATP (adenosine triphosphate); energy is released when its phosphate bond is broken to form ADP.

What is the difference between autotrophs and heterotrophs?

Autotrophs (producers) make their own food, usually via photosynthesis; heterotrophs (consumers) must obtain energy by consuming other organisms.

What molecule carries genetic information, and what are its four nitrogenous bases?

DNA carries genetic information. Its four bases are adenine (A), thymine (T), guanine (G), and cytosine (C); A pairs with T, and G pairs with C.

What is the difference between a genotype and a phenotype?

Genotype is the genetic makeup (the alleles an organism carries); phenotype is the observable physical trait that results from the genotype and environment.

In a monohybrid cross between two heterozygous parents ($Aa \times Aa$), what is the expected phenotypic ratio?

3:1 (three dominant phenotype to one recessive phenotype); the genotypic ratio is $1\ AA : 2\ Aa : 1\ aa$.

What is the difference between a dominant allele and a recessive allele?

A dominant allele is expressed in the phenotype whenever it is present; a recessive allele is only expressed when two copies are present (homozygous recessive).

What is the theory of evolution by natural selection, as proposed by Charles Darwin?

Organisms with heritable traits better suited to their environment are more likely to survive and reproduce, passing those advantageous traits to offspring, so the population changes over generations.

What four conditions are required for natural selection to occur?

Variation in traits, heritability of those traits, overproduction of offspring (competition), and differential survival/reproduction (selection).

What is the difference between an adaptation and a vestigial structure?

An adaptation is an inherited trait that improves survival/reproduction in a given environment; a vestigial structure is a reduced, functionless remnant of a structure that was useful in an ancestor.

What is the difference between a food chain and a food web?

A food chain is a single linear path of energy from producer to consumers; a food web is a network of many interconnected food chains in an ecosystem.

In an energy pyramid, approximately what percentage of energy is transferred from one trophic level to the next?

About $10\%$; the remaining $\sim 90\%$ is lost as heat, used for life processes, or undigested.

Arrange these ecological levels from smallest to largest: ecosystem, population, organism, community.

Organism, population, community, ecosystem.

What is the difference between a parasitic relationship and a mutualistic relationship?

In parasitism, one organism benefits while the host is harmed; in mutualism, both organisms benefit from the relationship.

What is homeostasis, and give one example in the human body.

Homeostasis is the maintenance of a stable internal environment despite external changes; an example is regulating body temperature near $37^{\circ}\text{C}$ through sweating or shivering.

Which human body system is responsible for transporting oxygen, nutrients, and wastes, and what are its main components?

The circulatory (cardiovascular) system; its main components are the heart, blood vessels (arteries, veins, capillaries), and blood.

What is the difference between the three subatomic particles in terms of charge and location?

Protons are positive and in the nucleus; neutrons are neutral and in the nucleus; electrons are negative and orbit the nucleus in electron clouds/shells.

What do the atomic number and the mass number of an atom tell you?

The atomic number equals the number of protons (and identifies the element); the mass number equals the number of protons plus neutrons.

What are isotopes?

Isotopes are atoms of the same element (same number of protons) that have different numbers of neutrons, and therefore different mass numbers.

How are elements arranged in the periodic table, and what do groups and periods represent?

Elements are arranged by increasing atomic number. Groups (columns) share similar chemical properties and the same number of valence electrons; periods (rows) indicate the number of electron shells.

What is the difference between an ionic bond and a covalent bond?

An ionic bond forms by the transfer of electrons between a metal and a nonmetal, creating charged ions; a covalent bond forms by the sharing of electrons between nonmetals.

What does the law of conservation of mass state about chemical reactions?

Matter is neither created nor destroyed in a chemical reaction, so the total mass of the reactants equals the total mass of the products (equations must be balanced).

What is the difference between an exothermic and an endothermic reaction?

An exothermic reaction releases energy (usually heat) to the surroundings; an endothermic reaction absorbs energy from the surroundings.

On the pH scale, what values indicate an acid, a base, and a neutral solution?

A pH below $7$ is acidic, a pH of $7$ is neutral, and a pH above $7$ is basic (alkaline). The scale runs from $0$ to $14$.

Name the four common states of matter and describe particle arrangement in solids versus gases.

Solid, liquid, gas, and plasma. In a solid, particles are tightly packed in fixed positions; in a gas, particles are far apart and move freely to fill their container.

What is the difference between a physical change and a chemical change?

A physical change alters form or appearance without creating a new substance (e.g., melting); a chemical change produces one or more new substances with different properties (e.g., burning).

State Newton's three laws of motion.

1) An object stays at rest or in uniform motion unless acted on by a net force (inertia). 2) $F = ma$. 3) For every action there is an equal and opposite reaction.

What is the formula for the net force on an object, and what are the SI units of force?

$F = ma$ (force equals mass times acceleration); the SI unit of force is the newton (N), where $1\ \text{N} = 1\ \text{kg·m/s}^{2}$.

What is the difference between speed and velocity?

Speed is a scalar quantity measuring how fast an object moves; velocity is a vector quantity that includes both speed and direction.

What is the formula for work, and what is the SI unit of work?

$W = F \times d$ (force times distance in the direction of the force); the SI unit is the joule (J).

What is the formula for power, and what is its SI unit?

$P = \frac{W}{t}$ (work divided by time); the SI unit is the watt (W), where $1\ \text{W} = 1\ \text{J/s}$.

What is the difference between kinetic energy and potential energy, and give the formula for kinetic energy.

Kinetic energy is the energy of motion, $KE = \frac{1}{2}mv^{2}$; potential energy is stored energy due to position or condition (e.g., gravitational $PE = mgh$).

For a wave, what is the relationship among wave speed, frequency, and wavelength?

$v = f \lambda$ (speed equals frequency times wavelength).

What is the difference between a transverse wave and a longitudinal wave?

In a transverse wave, particles vibrate perpendicular to the direction of wave travel (e.g., light); in a longitudinal wave, particles vibrate parallel to the direction of travel (e.g., sound).

What are the three methods of heat transfer?

Conduction (transfer through direct contact), convection (transfer through fluid movement), and radiation (transfer through electromagnetic waves).

State Ohm's law and define each variable.

$V = IR$, where $V$ is voltage (volts), $I$ is current (amperes), and $R$ is resistance (ohms).

What are the four main layers of the Earth from outside to inside?

Crust, mantle, outer core (liquid), and inner core (solid).

What is the theory of plate tectonics?

Earth's lithosphere is divided into rigid plates that float on the semi-fluid asthenosphere and slowly move, causing earthquakes, volcanoes, and mountain building at their boundaries.

Name and describe the three types of plate boundaries.

Convergent (plates move together, causing collisions/subduction), divergent (plates move apart, creating new crust), and transform (plates slide past each other, causing earthquakes).

What are the three main types of rock in the rock cycle, and how does each form?

Igneous rock forms from cooled magma/lava; sedimentary rock forms from compacted and cemented sediments; metamorphic rock forms from existing rock changed by heat and pressure.