Biology Vocabulary Flashcards: Digestive, Excretory, Genetics, Taxonomy

Vocabulary flashcards covering key terms from the digestive system, excretory system, Mendelian genetics, and taxonomy topics in the lecture notes.

Digestive system

The body system that processes food and liquids to absorb nutrients and eliminate waste.

Mouth

Entry point of food; site of ingestion, mechanical digestion (teeth) and chemical digestion (saliva).

Ingestion

Entry of food into the digestive tract.

Mechanical digestion

Physical breakdown of food into smaller pieces (e.g., chewing, churning).

Chemical digestion

Breakdown of food by chemicals/enzymes (e.g., saliva starts starch digestion).

Esophagus

Muscular tube that transports food to the stomach via peristalsis; no digestion occurs here.

Peristalsis

Wave-like muscular contractions that move food through the digestive tract.

Stomach

Hollow, muscular organ that stores food, churns it mechanically, and begins chemical digestion.

Small intestine

Long tube where most digestion completes and nutrients are absorbed.

Large intestine (Colon)

Absorbs water/electrolytes, forms/stores stool, supports gut bacteria.

Rectum

Stores stool until it is released.

Anus

Exit point for solid waste from the body.

Pancreas

Gland that produces digestive enzymes; also has hormonal roles in regulating blood sugar.

Liver

Largest internal organ; detoxifies substances, produces bile, helps regulate blood sugar.

Gallbladder

Stores and concentrates bile; releases bile into the small intestine to digest fats.

Bile

Digestive fluid that emulsifies fats to aid digestion.

Detoxification

Process of removing toxins from the body (liver primarily).

Excretory system

System that removes waste to maintain homeostasis.

Kidneys

Bean-shaped organs that filter blood to produce urine and balance fluids/electrolytes.

Nephron

Functional unit of the kidney; filters blood and forms urine.

Glomerulus

Tiny capillary network where filtration begins in the nephron.

Bowman’s capsule

Capsule that collects filtrate from the glomerulus.

Loop of Henle

Part of the nephron that concentrates filtrate by reabsorbing water and ions.

Distal Convoluted Tubule (DCT)

Nephron segment that reabsorbs ions and secretes wastes.

Collecting Duct

Final tube that collects urine and directs it toward the renal pelvis.

Ureters

Thin muscular tubes that move urine from kidneys to the bladder by peristalsis.

Urinary bladder

Hollow muscular sac that stores urine and signals when to urinate.

Urethra

Tube that carries urine from the bladder to the outside; in males also transports semen.

Lungs

Organs where gas exchange occurs; removes CO2 and supplies O2 via alveoli.

Skin

Excretory organ that releases water, salts, and small amounts of urea through sweat; helps regulate temperature.

Liver (excretory role)

Detoxifies harmful substances, converts ammonia to urea, and produces bile."

Mendelian genetics

Branch of genetics studying heredity and variation through simple inheritance.

Traits

Characteristics of an organism (e.g., eye color, height).

Heredity

Passing of traits from parents to offspring.

Genetics

Science that studies heredity and variation in organisms.

Genes

DNA segments that carry instructions for traits.

Alleles

Different versions of a gene.

Dominant allele

Allele that is expressed when present (masking others).

Recessive allele

Allele expressed only when two copies are present.

Genotype

Genetic makeup of an organism (e.g., TT, Tt, tt).

Phenotype

Physical traits or characteristics expressed by an organism.

Homozygous

Two identical alleles for a trait (e.g., TT or tt).

Heterozygous

Two different alleles for a trait (e.g., Tt).

Punnett Square

A chart used to predict possible offspring genotypes and phenotypes.

Law of Segregation

Each parent contributes one of two alleles for a trait to offspring.

Law of Independent Assortment

Genes for different traits are inherited independently of each other.

Law of Dominance

Dominant allele masks the expression of recessive allele.

Monohybrid Cross

Cross examining one trait (e.g., height) across generations.

Dihybrid Cross

Cross examining two traits simultaneously (e.g., color and shape).

Genotype vs Phenotype

Genotype is genetic makeup; phenotype is the observable trait.

Genome

Complete set of genetic material in an organism.

Chromosome

Structure made of DNA that carries genes.

DNA

Double-helix molecule that carries genetic information.

Gene

A DNA segment that codes for a specific trait.

Binomial nomenclature

Two-name naming system for species: Genus + species; italicized.

Genus

First name in binomial nomenclature; capitalized.

Species

Second name in binomial nomenclature; lowercase.

Homo sapiens

Scientific name for humans; example of binomial nomenclature.

Zea mays

Scientific name for corn; example of binomial nomenclature.

Taxonomy

Science of classifying and naming living organisms.

Hierarchical

Arranged in a rank-based order (from broad to specific).

Linnaeus

Father of taxonomy; developed the Linnaean system and Systema Naturae.

Systema Naturae

Carl Linnaeus' foundational work introducing a classification system.

Linnaean System

Classification system organized by nested ranks (Domain to Species).

Three-Domain System

Classification into Bacteria, Archaea, and Eukarya domains.

Domain

Highest taxonomic level (Domain → Kingdom → … → Species).

Kingdom

Second-highest rank in the Linnaean system (below Domain).

Phylum

Taxonomic rank below Kingdom; groups organisms by major body plan.

Genus

Taxonomic rank used in binomial nomenclature; group of related species.

Species

Group of organisms capable of interbreeding; basic unit of classification.

Bacteria

Prokaryotic domain; organisms found everywhere, some helpful, some harmful.

Archaea

Prokaryotic domain; live in extreme environments.

Eukarya

Domain of eukaryotic organisms (plants, animals, fungi, protists).