GED Science Test flashcards

A type of natural selection that favors individuals at both extremes of the phenotypic range over intermediate phenotypes.

• Favors extreme phenotypes
• Acts against intermediate phenotypes
• Can lead to speciation if extremes become reproductively isolated

Memory trick: SSD: Stabilize, Shift, Divide

Proactive public health measures aimed at containing a rapidly spreading infectious disease before it becomes widespread, often involving rapid identification and isolation.

• Focuses on breaking chains of transmission.
• Requires rapid response due to short incubation and high transmissibility.
• Key tools include testing, contact tracing, and isolation.

Memory trick: Early Epidemic Evasion requires Early Detection and Isolation.

A genetic inheritance pattern where the heterozygous phenotype is intermediate between the two homozygous phenotypes, appearing as a blend rather than one allele completely masking the other.

• Neither allele is fully dominant
• Heterozygotes show a blended phenotype
• Example: red + white = pink flowers
• Genotypic and phenotypic ratios are often identical

Memory trick: Dominance can be Complete, Incomplete, Co-dependent, or Sex-linked.

A warning signal, often vivid coloration, given by an animal to advertise its unpalatability, toxicity, or danger to potential predators.

• Serves as an antipredator defense mechanism.
• Often involves bright, contrasting colors (e.g., red, yellow, black).
• Predators learn to avoid such signals after negative experiences.

Memory trick: Aposematism is like a 'Danger! Keep Out!' sign.

A steroid hormone produced by the adrenal glands, often called the 'stress hormone' due to its role in the body's response to stress.

• Released by the adrenal cortex.
• Increases blood sugar, suppresses the immune system.
• Part of the 'fight or flight' response.
• Chronic elevation can be detrimental to health.

Memory trick: Endocrine's ACES: Adrenals, Cortisol, Energy, Stress.

An essential macronutrient for plants, crucial for the synthesis of amino acids, proteins, nucleic acids (DNA/RNA), and chlorophyll.

• Component of all amino acids and proteins.
• Required for chlorophyll, essential for photosynthesis.
• Deficiency leads to stunted growth and yellowing (chlorosis) of leaves.

Memory trick: Carnivorous plants eat bugs for 'N'itrogen, for 'N'ew growth.

Biconcave, anucleated cells in the blood that contain hemoglobin and are primarily responsible for oxygen transport throughout the body.

• Contain hemoglobin
• Transport oxygen and some carbon dioxide
• Lack a nucleus in mature form
• Produced in bone marrow

Memory trick: Red for Oxygen, White for Fight, Plates for Clot, Plasma for All Else.

Photoperiodism is the physiological response of plants and animals to the length of day or night. In plants, it often regulates flowering, dormancy, and leaf drop.

• Response to relative lengths of light and dark periods.
• Crucial for timing biological events like flowering.
• Plants are classified as short-day, long-day, or day-neutral.
• The length of the uninterrupted dark period is often critical.

Memory trick: Photo-period for plants, light for life's patterns!

The pancreas is an endocrine gland that produces hormones, primarily insulin and glucagon, which are essential for regulating blood glucose (sugar) levels in the body.

• Insulin lowers blood glucose.
• Glucagon raises blood glucose.
• Dysfunction leads to diabetes.

Memory trick: Pancreas: The body's Sugar Police.

A monohybrid cross involves two parents that are heterozygous for a single trait (e.g., Tt x Tt), where one allele is dominant over the other. The resulting phenotypic ratio is typically 3:1 for dominant to recessive traits.

• Parents are both heterozygous (e.g., Tt).
• Dominant allele masks the recessive allele's expression.
• Punnett square is used to predict offspring genotypes and phenotypes.

Memory trick: Three tall, one short, that's the heterozygous lot!

Bacterial meningitis is an infection of the meninges (membranes surrounding the brain and spinal cord). Cerebrospinal fluid (CSF) analysis is crucial for diagnosis.

• High white blood cell count (predominantly neutrophils)
• Low glucose levels (bacteria consume glucose)
• Elevated protein levels (inflammation and bacterial byproducts)

Memory trick: CSF clues: High WBC, Low Glucose, High Protein = Bad Bug!

Intrinsic factor is a protein secreted by the parietal cells of the stomach, vital for the absorption of Vitamin B12 in the ileum (the final section of the small intestine).

• Produced by parietal cells in the stomach.
• Binds to Vitamin B12, protecting it from digestion.
• Facilitates B12 absorption in the ileum.
• Deficiency leads to pernicious anemia.

Memory trick: Intrinsic factor's missing, B12's fleeing, anemia's appearing!

T-lymphocytes (T cells) are key components of the adaptive immune system, responsible for cell-mediated immunity. In autoimmune diseases, they mistakenly target and attack healthy self-tissues. Medications suppressing T-cell activity aim to reduce this self-destructive response.

• T cells are central to cell-mediated immunity.
• In autoimmune diseases, T cells attack self-antigens.
• Suppression of T-cell activity reduces inflammation and tissue damage.
• Often used in transplant patients to prevent rejection and in autoimmune conditions.

Memory trick: T-cells are attackers; suppress them to stop the self-attack!

Prokaryotic cells are the simplest and most ancient forms of life. They are characterized by the absence of a membrane-bound nucleus and other membrane-bound organelles.

• Lack a true nucleus; genetic material in nucleoid region.
• Do not have membrane-bound organelles (e.g., mitochondria, ER).
• Typically single-celled organisms (bacteria, archaea).
• Smaller and simpler in structure than eukaryotic cells.

Memory trick: Pro-no nucleus, Eu-do nucleus!

B-lymphocytes are a type of white blood cell (lymphocyte) that plays a central role in humoral immunity by differentiating into plasma cells and producing antibodies.

• Originate and mature in bone marrow.
• Recognize specific antigens through B cell receptors.
• Differentiate into plasma cells upon activation.
• Plasma cells produce and secrete antibodies.

Memory trick: B for B-cell, B for Bodyguards (antibodies)!

An ecological niche describes the role and position a species has in its environment, including how it meets its needs for food and shelter. Disruption of a key food source profoundly impacts species with specialized diets.

• Specialized feeders are vulnerable to changes in their primary food source.
• Food webs illustrate feeding relationships; removal of one component affects others.
• Population dynamics are directly linked to resource availability.

Memory trick: No jellyfish, no turtles, ecosystem in crisis!

T lymphocytes (T cells) are a type of white blood cell that plays a central role in cell-mediated immunity, including recognizing and differentiating between self and non-self cells to protect against pathogens and prevent autoimmunity.

• Mature in the thymus.
• Recognize specific antigens presented by MHC molecules.
• Crucial for both adaptive immunity and preventing autoimmune diseases.

Memory trick: Immunity's T-team: Targeting Trouble, Trusting 'Self'.

Vector-borne diseases are transmitted by vectors (e.g., mosquitoes, ticks). Control strategies focus on breaking the chain of transmission, often by targeting the vector or protecting humans from bites.

• Focus on vector control (e.g., reducing breeding sites).
• Personal protection (e.g., repellents, nets) is crucial.
• Vaccination, if available, is a long-term preventive measure.
• Early detection and treatment of cases also reduce spread.

Memory trick: Stop the bite, ditch the water, then maybe vaccinate later!

Directional selection is a mode of natural selection in which an extreme phenotype is favored over other phenotypes, causing the allele frequency to shift over time in the direction of that phenotype.

• Favors one extreme of the phenotypic range.
• Leads to a shift in the population's average trait value.
• Common in environments undergoing change.
• Example: increasing beak size in finches during drought.

Memory trick: Directional goes one way, Stabilizing stays the same, Disruptive splits apart!

The parathyroid glands are small endocrine glands located in the neck that produce parathyroid hormone (PTH), which plays a crucial role in regulating calcium and phosphate homeostasis in the blood and bones.

• Located behind the thyroid gland.
• PTH increases blood calcium by acting on bones, kidneys, and intestines.
• PTH decreases blood phosphate levels.

Memory trick: Para-Calcium's Partner: PTH's Power Play.

Acquired Immunodeficiency Syndrome (AIDS) is the most advanced stage of HIV infection, characterized by a severely compromised immune system, leading to a high susceptibility to opportunistic infections and certain cancers.

• Caused by the Human Immunodeficiency Virus (HIV).
• Defined by a CD4+ T cell count below 200 cells/µL or presence of AIDS-defining conditions.
• Opportunistic infections (e.g., Pneumocystis pneumonia, Kaposi's sarcoma) are common.
• Results in profound immunodeficiency and increased mortality if untreated.

Memory trick: HIV attacks CD4s, AIDS brings opportunists and fatigue!

Nuclear fission is a nuclear reaction in which the nucleus of an atom splits into two or more smaller, lighter nuclei, often producing gamma photons and releasing a very large amount of energy.

• Used in nuclear power plants.
• Involves heavy elements like Uranium-235.
• Initiated by neutron bombardment.

Memory trick: Nuclear energy is either 'Splitting' or 'Sticking'.

Noble gases are a group of chemical elements with similar properties; under standard conditions, they are all odorless, colorless, monatomic gases with very low chemical reactivity.

• Located in Group 18 of the periodic table.
• Have a full valence electron shell (octet rule satisfied, except for helium with a duet).
• This electron configuration makes them highly stable and chemically inert.

Memory trick: Noble gases are naturally 'full' and don't need to 'share' their electron 'shelter'.

Immiscibility is the property of two liquids that are not capable of being mixed to form a homogeneous solution; they will separate into distinct layers.

• Often due to differences in polarity (like dissolves like).
• Results in heterogeneous mixtures.
• Examples include oil and water.

Memory trick: Liquids are either 'Mix-able' or 'No-Mix-able'.

The strength of an electromagnet is determined by several factors, including the number of turns in the coil, the current flowing through the coil, and the nature of the core material.

• More turns = stronger field.
• Higher current = stronger field.
• Ferromagnetic core (like iron) = stronger field.

Memory trick: Electromagnet strength is built by 'Current, Coils, and Core'.

The speed of sound varies depending on the medium it travels through, generally being faster in denser and more rigid materials.

• Sound travels fastest in solids.
• Sound travels slower in liquids than in solids.
• Sound travels slowest in gases.

Memory trick: Sound loves to zoom through the 'Solid, Liquid, Gas' highway.

Fluorescence is a type of luminescence where a substance absorbs electromagnetic radiation (typically UV light) and then re-emits light at a longer wavelength (visible light) almost instantaneously.

• Emission stops almost immediately when excitation source is removed.
• Used in fluorescent lights, security features, and biological imaging.
• Different from phosphorescence, which has a delayed emission.

Memory trick: Light can be 'Flashing, Lingering, or Chemical'.

The Inverse Square Law states that the intensity of a physical quantity (such as light, sound, or gravity) is inversely proportional to the square of the distance from the source.

• As distance doubles, intensity becomes one-fourth.
• Applies to phenomena radiating uniformly in all directions.
• Fundamental concept in physics, astronomy, and engineering.

Memory trick: Light is 'Inversely Squared' for distance, like a faint star.

The mechanical advantage of a lever is the ratio of the output force (load) to the input force (effort), or the ratio of the effort arm length to the load arm length. It indicates how much a lever multiplies force.

• MA = Effort Arm Length / Load Arm Length.
• Higher MA means less effort force needed.
• Fulcrum position is key to determining MA.

Memory trick: Levers give an 'Advantage' by balancing arms.

Chemical inertness is the property of a substance that describes its lack of reactivity with other chemical substances.

• Inert substances do not readily undergo chemical reactions.
• Noble gases are well-known for their chemical inertness.
• This property is useful in applications requiring protection from chemical change.

Memory trick: Shielding gas must be the 'Silent Guardian' of the weld.

A pH indicator made of a solution of several compounds that exhibits several color changes over a wide range of pH values to indicate the acidity or alkalinity of solutions.

• Changes color based on pH (potential of hydrogen).
• Red/Orange = Acidic (low pH)
• Green = Neutral (pH 7)
• Blue/Purple = Basic (high pH)

Memory trick: Remember 'Red for Acid, Green for Clean (Neutral), Blue for Base' with Universal Indicator.

For an object in a circular orbit, the centripetal force, which causes the object to continuously accelerate towards the center of its path, is provided by the gravitational attraction between the orbiting body and the central body.

• Centripetal force is always directed towards the center of the circular path.
• It causes a change in direction of velocity, not necessarily speed.
• For satellites, gravity is the centripetal force.

Memory trick: Satellites 'Gravitate' to the center, constantly turning.

Energy dissipation is the process by which energy is transformed from more useful forms (like mechanical energy) into less useful or unusable forms (like heat or sound) due to non-conservative forces such as friction and air resistance.

• Reduces the total mechanical energy of a system.
• Always occurs in real-world physical systems.
• Often results in energy being converted to heat.

Memory trick: Real systems 'Dissipate' energy, like a fading echo.

Specialized immune cells that directly recognize and kill host cells infected with intracellular pathogens (like viruses) or cancerous cells by identifying specific antigens presented on their surface.

• Part of adaptive immune system.
• Recognize specific antigens presented by MHC Class I molecules.
• Induce apoptosis (programmed cell death) in target cells.

Memory trick: T-cells Target Trouble, B-cells Block Badness.

Methods used to reduce or eliminate populations of disease-carrying organisms (vectors), such as insects or rodents, to prevent the transmission of vector-borne diseases.

• Targets the disease transmitter, not the pathogen or host.
• Examples: insecticide spraying, habitat modification, sterile insect technique.
• Crucial for diseases like malaria, dengue, Zika.

Memory trick: Host, Pathogen, Vector, Environment – Break the Chain.

S-waves (shear waves) are a type of seismic wave that can only propagate through solid materials, providing evidence for the state of matter of Earth's interior layers.

• Cannot travel through liquids or gases
• Used to determine the liquid nature of the outer core
• Travel slower than P-waves

Memory trick: S-waves: Solids only, no swimming in the core!

An insulating layer, primarily composed of lipids and proteins, that forms around nerves, including those in the brain and spinal cord, allowing electrical impulses to transmit quickly and efficiently along the nerve cells.

• Increases nerve impulse conduction speed.
• Protects axons.
• Formed by Schwann cells (PNS) and oligodendrocytes (CNS).

Memory trick: My Fast Nerves Relay Signals.