1STQ SCI 8 Periodical Examination (PDF)

A set of vocabulary flashcards covering key terms from digestion, excretion, genetics inheritance patterns, and classification systems.

Digestive System

Series of organs that break down food into absorbable nutrients and eliminate waste.

Mechanical processing

Physical breakdown of food by chewing (mouth) and stomach churning.

Secretion

Release of substances like saliva and gastric juice that aid digestion.

Absorption

Uptake of digested nutrients into blood or lymph.

Elimination

Removal of undigested waste from the body through the digestive tract.

Mastication

Chewing; mechanical processing of food in the mouth.

Amylase

Enzyme in saliva that starts starch digestion.

Bolus

Chewed food mass formed for swallowing.

Peristalsis

Wave-like muscle contractions moving food through the GI tract.

Mouth (Oral Cavity)

Opening where food enters; site of mechanical processing and initial secretion.

Pharynx

Throat region where swallowing begins to move food toward the esophagus.

Esophagus

Muscular tube that transports bolus to the stomach via peristalsis.

Stomach

Organ where churning and chemical digestion (HCl, pepsin) occur to form chyme.

Gastric glands

Glands that produce HCl, pepsinogen, and mucus in the stomach.

Hydrochloric acid (HCl)

Acid in gastric juice that activates pepsin and helps digest proteins.

Pepsinogen

Inactivated enzyme converted to pepsin by HCl to digest proteins.

Pepsin

Protein-digesting enzyme in the stomach.

Mucus

Protects stomach lining and lubricates contents.

Chyme

Thick liquid formed after stomach digestion.

Duodenum

First part of the small intestine where chemical digestion completes.

Bile

Digestive fluid produced by liver and stored in gallbladder; emulsifies fats.

Pancreatic enzymes

Amylase, lipase, and proteases released into the duodenum to digest carbs, fats, proteins.

Jejunum

Midsection of the small intestine where most nutrient absorption occurs.

Ileum

Final section of the small intestine; absorption continues.

Villi

Finger-like projections in the small intestine that increase surface area for absorption.

Microvilli

Tiny projections on villi increasing surface area for absorption.

Lacteals

Lymphatic vessels in the villi that absorb fats.

Nutrient absorption

Process of moving digested nutrients into blood or lymph.

Large Intestine

Absorbs water and electrolytes; forms feces.

Cecum

First section of the large intestine.

Rectum

Final section of the large intestine where feces are stored before elimination.

Anus

Opening through which feces exit the body.

Feces

Solid waste excreted via the rectum and anus.

Kidneys

Organs that filter blood to remove wastes and regulate water and electrolytes.

Ureters

Tubules that transport urine from kidneys to the bladder.

Urinary bladder

Stores urine before elimination.

Urethra

Tube that carries urine out of the body.

Urine

Liquid waste excreted by the kidneys.

Six-Kingdom System

Classification system dividing life into six kingdoms: Archaebacteria, Eubacteria, Protista, Fungi, Plantae, Animalia.

Archaebacteria

Prokaryotic, unicellular organisms living in extreme environments; ancient origins.

Eubacteria

Prokaryotic, unicellular organisms found everywhere; some beneficial, some harmful.

Protista

Mostly unicellular eukaryotes with varied nutrition.

Fungi

Eukaryotic, mostly multicellular organisms that absorb nutrients; decomposers.

Plantae

Eukaryotic, multicellular autotrophs (photosynthesis).

Animalia

Eukaryotic, multicellular heterotrophs.

Three-Domain System

Classification into Bacteria, Archaea, and Eukarya based on genetic differences.

Bacteria

Corresponds to Kingdom Eubacteria; prokaryotic organisms.

Archaea

Corresponds to Kingdom Archaebacteria; prokaryotic organisms often in extreme environments.

Eukarya

Domain containing Protista, Fungi, Plantae, Animalia; eukaryotes.

rRNA

Ribosomal RNA; used to distinguish domains in the Three-Domain System.

Trait

A characteristic determined by genes.

Gene

A DNA segment that controls a trait.

Allele

Different forms of a gene; dominant or recessive.

Dominant

An allele expressed when present; typically shown with a capital letter.

Recessive

An allele expressed only when both alleles are recessive; typically lowercase.

Homozygous

Having identical alleles (AA or aa).

Heterozygous

Having different alleles (Aa).

Genotype

Genetic makeup of an individual.

Phenotype

Physical expression of the genotype.

Monohybrid cross

Cross examining one trait; yields 3:1 phenotypic ratio and 1:2:1 genotypic ratio.

Cross

Breeding between individuals to study inheritance.

Punnett Square

Grid used to predict offspring genotypes and phenotypes.

Genotypic ratio

Proportions of genotypes among offspring (e.g., 1:2:1).

Phenotypic ratio

Proportions of phenotypes among offspring (e.g., 3:1).

Test cross

Cross with a homozygous recessive to determine unknown genotype.

Dihybrid cross

Cross examining two traits; yields 9:3:3:1 phenotypic ratio.

FOIL

First-Outer-Inner-Last method to determine gamete combinations in dihybrid crosses.

9:3:3:1

Classic dihybrid phenotypic ratio.