General Biology 2 Finals Review

Flashcards covering animal and plant defense responses, hormones, sensory systems, nutrition, reproduction, and development.

1st Line of Defense

Physical and chemical barriers, which are non-specific.

2nd Line of Defense

Non-specific immunity, including inflammatory response and phagocytes.

3rd Line of Defense

Specific immunity involving antibodies and lymphocytes.

Skin

Made of keratinized cells; acts as an impenetrable barrier.

Mucous Membrane

Line body cavities; trap pathogens but are more vulnerable than skin.

Nasal Hair

Filters large particles and microbes from the air.

Sweat

Washes away microbes; acidic, slowing bacterial growth.

Mucus

Sticky, traps pathogens.

Saliva & Tears

Contain lysozyme, an enzyme that breaks bacterial cell walls.

Cerumen (Earwax)

Traps dust and microbes; inhibits bacterial growth.

Stomach Acid

Hydrochloric acid that kills ingested pathogens.

Urine

Flow flushes out bacteria from the urethra.

Vaginal Secretions

Acidic pH inhibits pathogenic growth.

Phagocytes

White blood cells that “eat” or engulf pathogens, damaged cells, and debris.

Neutrophils

First to arrive at infection sites; fast-acting phagocytes.

Macrophages

Larger, long-lasting phagocytes that engulf and digest more pathogens.

Eosinophils

Target large invaders like parasitic worms by releasing toxic enzymes.

Natural Killer (NK) Cells

Patrol the body, looking for abnormal or infected cells and destroying them.

Interferons

Proteins released by virus-infected cells that warn nearby cells and help block virus replication.

Complement System

A group of proteins that mark pathogens for destruction, punch holes in their membranes, and trigger inflammation.

Redness

More blood flow to the area during inflammation.

Swelling

Fluid and immune cells moving into tissue during inflammation.

Inborn (Innate) Immunity

Passed down genetically from parents/ancestors; present at birth; general protection.

Acquired (Adaptive) Immunity

Develops after exposure to specific antigens; can be natural or artificial.

Antibodies or Immunoglobulins (Ig)

Proteins made by B lymphocytes that bind to specific antigens and help destroy them.

IgG

Most abundant in blood; provides long-term immunity after infection or vaccination; can cross the placenta.

IgA

Found in mucosal areas; protects mucous membranes.

IgM

First antibody produced in response to infection; found in blood and lymph.

IgE

Involved in allergic reactions; protects against parasitic infections.

IgD

Found on immature B cells; helps initiate early B cell activation.

Vaccination

Process of introducing an attenuated or weakened antigen in a susceptible host.

Detection (Plant Defense)

Special receptors in plant cells detect molecules from invading pathogens and damage-related chemicals.

Signal Activation (Plant Defense)

Detection triggers the release of signaling molecules, which activate genes in the nucleus.

Response Activation (Plant Defense)

Activated genes lead to defensive responses, including making defensive chemicals, sending alarm signals, and strengthening cell walls.

Cuticle

Waxy layer secreted by the epidermis; reduces water loss and blocks microbes.

Cell Wall

Tough outer layer of plant cells; resists invasion.

Stomata

Can close to prevent pathogen entry.

Callose

Sugar-based substance deposited in cell walls during attack; blocks pathogen movement.

Trichomes

Hair-like structures that trap or injure invaders.

Bark

Protective outer covering of plants.

Thorns/Spines

Deter herbivores.

Cyanogenic Glycosides

Release cyanide when eaten; blocks cellular respiration.

Neurotoxins

Extremely poisonous; can kill in under 3 hours.

Ricin

Found in castor beans; 6x more lethal than cyanide.

Alkaloids (Secondary Metabolites)

Affect nervous system of pests (e.g., caffeine, cocaine, nicotine, morphine).

Allelopathy

Some plants release chemicals into the soil that inhibit the growth of nearby plants.

Rhizobium

Nitrogen-fixing bacteria that convert nitrogen in the soil into nitrates for plant use.

Rhizobacteria

Live around plant roots, feed on root secretions, and produce helpful substances like hormones.

Hormone

A chemical messenger made in special glands, released into the bloodstream to signal target organs or cells.

Endocrine Glands

Release hormones directly into the blood; no ducts.

Exocrine Glands

Release substances through ducts (e.g., saliva, sweat).

Pheromones

Chemicals released into the environment for communication.

PTTH (Prothoracicotropic Hormone)

Stimulates release of ecdysone, controls molting and metamorphosis in insects.

Parathyroid Hormone

Controls calcium levels in blood.

Adrenaline, Noradrenaline

Produces adrenaline for “fight or flight.”

Cortisol, Aldosterone

Regulates metabolism and stress response.

Insulin, Glucagon

Controls blood sugar levels.

Estrogen

Stimulates development of female secondary sex characteristics.

Progesterone

Stimulates development of mammary glands; completes prep for pregnancy.

Testosterone

Stimulates male sex secondary characteristics.

Melatonin

Regulates sleep cycle.

Follicle-Stimulating Hormone (FSH)

Stimulates egg/sperm production.

Luteinizing Hormone (LH)

Triggers ovulation/testosterone production.

Growth Hormone (GH)

Stimulates growth and cell division, regulates metabolism.

Thyroid-Stimulating Hormone (TSH)

Stimulates thyroid activity.

Adrenocorticotropic Hormone (ACTH)

Stimulates adrenal cortex.

Prolactin

Stimulates milk production.

Oxytocin

Stimulates contractions during childbirth and milk release.

Antidiuretic Hormone (ADH)

Regulates water balance by controlling urine output.

Auxin

Stimulates cell elongation, controls apical dominance, promotes root growth, regulates tropisms.

Cytokinin

Promotes cell division and differentiation; balances shoot and root growth; delays aging.

Gibberellic Acid (GA)

Stimulates stem elongation, seed germination, flowering; helps fruit grow.

Abscisic Acid (ABA)

Inhibits growth; triggers seed dormancy; causes stomatal closure during stress.

Ethylene

Promotes fruit ripening, leaf drop; speeds up aging; helps plants respond to stress.

Brassinosteroids

Encourage cell elongation and division; aid flowering, seed germination, and stress responses.

Oligosaccharins

Help plants defend against pathogens and herbivores.

Photomorphogenesis

Light-triggered development affecting germination, stem growth, leaf expansion, flowering.

Phototropism

Growth in response to light direction.

Thigmotropism

Directional growth from physical contact.

Thigmonasty

Non-directional response to touch.

Seed Dormancy

Seeds stay inactive until conditions are right, preventing germination during harsh conditions.

Abscission

Natural shedding of leaves, flowers, or fruit.

Digestion

Breaking down food into smaller particles.

Absorption

Nutrients enter the bloodstream or lymph after digestion.

Herbivores

Plant-eaters with digestive systems capable of handling large amounts of plant material.

Carnivores

Meat-eaters.

Omnivores

Eat both plant and animal-derived food.

Vitamins

Organic compounds that function as co-enzymes and co-factors of enzymes.

Minerals

Inorganic molecules that provide ions essential for the functioning of many enzymes or proteins.

Macronutrients (Principal Elements)

Needed in large amounts (>100 mg/day).

Micronutrients (Trace Elements)

Needed in small amounts (<100 mg/day).

Gastrovascular Cavity

One opening acts as both mouth and anus; a blind cavity where digestion happens.

Alimentary Canal

Separate mouth and anus.

Peristalsis

Wave-like smooth muscle movement pushing bolus to the stomach.

Pepsin

Breaks proteins into peptides (short chains of amino acids) in the stomach.

Micelles

Tiny fat droplets surrounded by bile salts, aiding lipid absorption.

Elimination

Final step: removing undigested food as waste (feces).

Photosynthesis

Process that turns solar energy into chemical energy.

Chlorophyll

Green pigment inside chloroplasts that absorbs light energy.

Thylakoids

Connected sacs in the chloroplasts where chlorophyll is located.