Model Textbook of Biology Grade 9 (Pakistan NC 2022-23) Vocabulary Flashcards

500 vocabulary-style flashcards covering core topics from the Model Textbook of Biology Grade 9, including biology basics, biodiversity, cell biology, cell cycle, tissues, leaves, and related sciences.

Biology

The science that studies living organisms and their interactions with their environment.

Biodiversity

The variety and variability of life on Earth.

Classification

Grouping of related organisms into classes based on similarities.

Taxonomy

The science of naming, describing, and classifying organisms.

Systematics

The scientific study of evolutionary relationships among organisms.

Domain

The highest traditional taxonomic rank; domains are Archaea, Bacteria, and Eukarya.

Archaea

A domain of prokaryotic organisms often inhabiting extreme environments.

Bacteria

A domain of prokaryotic microorganisms with peptidoglycan in their cell walls.

Eukarya

Domain of organisms with eukaryotic cells (nuclei and organelles).

Protista

Kingdom of mostly unicellular eukaryotes; diverse group.

Fungi

Kingdom of eukaryotic, mostly saprotrophic organisms with chitin in cell walls.

Plantae

Kingdom of autotrophic, photosynthetic eukaryotes with cellulose cell walls.

Animalia

Kingdom of multicellular, heterotrophic eukaryotes lacking cell walls.

Monera

Historic kingdom covering prokaryotes (bacteria and archaea) in older systems.

Virus

An acellular infectious agent that hijacks a host cell to replicate.

Prion

Misfolded protein causing infectious neurodegenerative diseases.

Viroid

Small infectious RNA lacking a protein coat.

Cell

The basic unit of life; structure and function unit of organisms.

Cell membrane

Semipermeable boundary that regulates substance exchange with the environment.

Cytoplasm

Jelly-like interior of the cell where metabolic activities occur.

Nucleus

Control center of the cell containing genetic material (DNA).

Nucleolus

Site of ribosomal RNA (rRNA) synthesis and ribosome assembly.

Chromatin

DNA-protein complex in the nucleus during interphase.

Chromosome

Condensed DNA structures visible during cell division carrying genes.

Endoplasmic reticulum (ER)

Membrane network; rough ER has ribosomes; smooth ER lacks ribosomes.

Rough ER

ER surface studded with ribosomes; synthesizes proteins.

Smooth ER

ER lacking ribosomes; synthesizes lipids and detoxifies.

Ribosome

Ribonucleoprotein particles where protein synthesis occurs.

Golgi apparatus

Organelle that modifies, sorts, and packages proteins for transport.

Lysosome

Digestive enzyme–containing vesicle for intracellular digestion.

Mitochondrion

Powerhouse of the cell; produces ATP via respiration.

Chloroplast

Plastid containing chlorophyll; site of photosynthesis.

Plastids

Double-membrane bound organelles in plants/algae (chloroplasts, chromoplasts, leucoplasts).

Chlorophyll

Green pigment responsible for capturing light in photosynthesis.

Granum

Stack of thylakoids within a chloroplast.

Thylakoid

Membranous sacs inside chloroplasts where light reactions occur.

Stroma

Fluid matrix inside chloroplasts where the Calvin cycle occurs.

Stomata

Pores in leaf epidermis regulated by guard cells for gas exchange.

Guard cells

Specialized cells that regulate stomatal opening and closing.

Vacuole

Membrane-bound sac for storage; large central vacuole in plant cells.

Tonoplast

Membrane surrounding the central vacuole in plant cells.

Cell wall

Rigid layer outside the plant cell membrane; composed of cellulose.

Cellulose

Polysaccharide forming the primary component of plant cell walls.

Plasmodesmata

Cytoplasmic channels through plant cell walls connecting adjacent cells.

Prokaryote

Organism whose cells lack a nucleus and membrane-bound organelles.

Eukaryote

Organism whose cells contain a nucleus and membrane-bound organelles.

Peptidoglycan

Polymeric compound forming bacterial cell walls.

Archaea extremophiles

Archaea adapted to extreme environments (temperature, salinity, pH).

Methanogens

Archaea that produce methane as a metabolic byproduct.

Halophiles

Archaea that thrive in high-salt environments.

Thermoacidophiles

Archaea that survive high temperature and acidic conditions.

rRNA

Ribosomal RNA; component of ribosomes used in protein synthesis.

DNA

Deoxyribonucleic acid; genetic material carrying hereditary information.

RNA

Ribonucleic acid; involved in protein synthesis and gene regulation.

Binomial nomenclature

Two-term Latin naming system: Genus + species.

Genus

Taxonomic rank above species; capitalized in binomial names.

Species

Basic unit of classification; group of organisms capable of interbreeding.

Homo sapiens

Scientific name for humans.

Solanum tuberosum

Scientific name for potato.

Solanum melongena

Scientific name for eggplant.

Oryza sativa

Scientific name for rice.

Phylogeny

Evolutionary relationships among organisms.

Taxonomic ranks

Levels of classification: Domain, Kingdom, Phylum/Division, Class, Order, Family, Genus, Species.

Phylum

Major group within a kingdom (plants/fungi: division).

Division

Plant/Fungi equivalent of phylum in some systems.

Class

Taxonomic rank below phylum/division and above order.

Order

Taxonomic rank below class and above family.

Family

Taxonomic rank below order and above genus.

Genus

Taxonomic rank above species; includes related species.

Species epithet

Second part of binomial name; species identifier.

Domain Archaea

Archaea domain with prokaryotic cells; often extremophiles.

Domain Bacteria

Bacteria domain with prokaryotic cells; peptidoglycan in walls.

Domain Eukarya

Eukaryotic domain: Protista, Fungi, Plantae, Animalia.

Viruses

Acellular infectious agents; require host cells to replicate.

Prions

Protein particles causing transmissible diseases.

Viroids

Small infectious RNA molecules; lack protein coat.

Malaria

Disease caused by Plasmodium parasites, transmitted by mosquitoes.

Plasmodium

Malaria parasite; causative agent of malaria.

Mosquito vector

Organism that transmits a parasite or pathogen (vector).

Anopheles

Mosquito genus that transmits human malaria.

Culex

Mosquito genus associated with avian malaria and other diseases.

Aedes

Mosquito genus that transmits dengue and other viruses.

Dengue fever

Viral disease transmitted by Aedes mosquitoes.

Ross

Ronald Ross; demonstrated malaria transmission by mosquitoes.

Laveran

Charles Louis Alphonse Laveran; discovered malaria parasite.

King (A.F.A King)

Early observer of malaria transmission factors.

Incubation period

Time between infection and appearance of symptoms.

Vector transmission

Spread of pathogens by a living carrier.

Meiosis

Cell division producing four haploid gametes; genetic variation occurs.

Mitosis

Cell division producing two diploid daughter cells with identical chromosomes.

Cytokinesis

Division of cytoplasm following mitosis/meiosis.

Prophase

First stage of mitosis; chromosomes condense.

Metaphase

Chromosomes align at the cell equator.

Anaphase

Sister chromatids separate and move to opposite poles.

Telophase

Nuclei re-form around separated chromatids.

Spindle apparatus

Microtubule structure that separates chromosomes during division.

Centrioles

Paired organelles in animal cells that organize spindle fibers.

Phragmoplast

Plant cell structure guiding cell plate formation during cytokinesis.

Cytokinesis (animal vs plant)

Animal cells form a cleavage furrow; plant cells form a cell plate.

G1 phase

First gap phase of the cell cycle; growth and preparation.