Science Biology College Admission Test (CAT) Review

Comprehensive vocabulary flashcards covering biology topics ranging from microscopy and cellular biology to genetics, anatomy, and evolutionary theories for college admission test preparation.

Eyepiece (Ocular Lens)

The part of the microscope where you look through, which magnifies the image of the specimen.

Total Magnification

The value calculated by multiplying the ocular lens power by the objective lens power: $Total Magnification = Ocular Lens \times Objective Lens$.

Homeostasis

The maintenance of a stable, relatively constant internal environment within a living organism.

Metabolism

The total of all biochemical reactions occurring inside an organism's body.

Anabolic

A metabolic process where small molecules are assembled into large ones, requiring an input of energy.

Catabolic

A metabolic process where large molecules are broken down into small ones, resulting in the release of energy.

Natural Selection

Darwin's theory that individuals with helpful traits will leave more offspring in the next generation than their peers.

Theory of Use and Disuse

Lamarck's theory stating that organs used frequently develop while characteristics used seldom are lost in succeeding generations.

Prokaryotic Cells

Cells characterized by the absence of a true nucleus, no membrane-bound organelles, and DNA located in a nucleoid region.

Eukaryotic Cells

Cells with DNA confined in a double-membrane nucleus and containing membrane-bound organelles like mitochondria and the Golgi apparatus.

Nucleus

The control center of cellular activities that stores DNA, synthesizes RNA, and produces ribosomes in the nucleolus.

Plasma Membrane

A selectively permeable phospholipid bilayer with embedded proteins that regulates the movement of substances in and out of the cell.

Mitochondria

The powerhouse of the cell responsible for extracting energy from food through cellular respiration to create $ATP$; it contains its own DNA and inner folds called cristae.

Lysosomes

Single membrane-bound organelles filled with digestive enzymes used to remove waste and digest dead cells; also called 'suicidal bags'.

Cell Theory

The theory stating all living organisms are composed of one or more cells, the cell is the basic unit of life, and all cells arise from pre-existing cells.

Cell Cycle

A series of events involving growth ($G1$), DNA replication ($S$), preparation for division ($G2$), and mitosis ($M$).

Mitosis

A type of cell division resulting in two genetically identical diploid daughter cells, used primarily for body cell production.

Meiosis

A two-round cell division process that produces four non-identical haploid gametes (sex cells) and involves crossing-over.

Crossing Over

A process during meiosis where homologous chromosomes exchange segments of genetic material to increase genetic diversity.

Fluid Mosaic Model

The concept that the cell membrane is a liquid where lipids, proteins, and carbohydrates can diffuse freely across its surface.

Isotonic Solution

A solution where the concentration of solutes is the same inside and outside the cell, resulting in no net movement of water.

Hypotonic Solution

A solution with a lower solute concentration outside the cell than inside, causing solvent to enter the cell.

Hypertonic Solution

A solution with a higher solute concentration outside the cell than inside, causing solvent to exit the cell.

DNA Replication

The semiconservative biological process of producing two identical replicas of DNA from one original DNA molecule.

Helicase

The enzyme responsible for unwinding and unzipping the parental double helix during DNA replication.

DNA Polymerase

The enzyme that adds new complementary nucleotide bases to form new DNA strands and proofreads the synthesized strand.

Ligase

The enzyme that joins and seals newly synthesized strands of DNA together.

Transcription

The process where information stored in a DNA strand is copied into a new molecule of $mRNA$.

Translation

The process of converting the information in $mRNA$ into a sequence of amino acids linked by peptide bonds to form a protein.

Glycolysis

The first step of cellular respiration where a sugar molecule like glucose is split in half, generating two molecules of $ATP$.

Aerobic Respiration

An oxygen-dependent process represented by the equation: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + 36ATP$.

Taxonomy

The branch of biology developed by Carolus Linnaeus that classifies all living things into a specific hierarchy.

Archaea

A domain of prokaryotic organisms without peptidoglycan in their cell walls that often thrive in extreme environments.

Heterotrophs

Organisms that cannot manufacture their own food and must oxidize organic materials for nutrition; also known as consumers.

Autotrophs

Organisms that produce their own food from inorganic sources using light (photoautotrophs) or chemicals (chemoautotrophs).

Phytohormones

Chemical compounds found in plants that control growth, development, reproductive processes, and environmental responses.

Auxins

A class of plant hormones responsible for cell enlargement, elongation, and responses to sunlight and gravity.

Phototropism

The directional growth of an organism, such as a plant stem, in response to light.

Alveoli

Tiny balloon-like structures in the lungs surrounded by capillaries where gas exchange between oxygen and carbon dioxide occurs.

Brainstem

The part of the brain connecting the cerebrum to the spinal cord, responsible for vital autonomic functions like heartbeat and breathing.

Pituitary Gland

A pea-sized endocrine gland located at the base of the brain known as the 'Master gland' for its role in controlling other glands.

Uniformitarianism

The geological theory stating that Earth's crust changes result from uniform, continuous processes that are still occurring today.

Law of Independent Assortment

Mendel's law stating that genes for different traits are inherited independently of each other if they are on different chromosomes.

Codominance

A non-Mendelian inheritance pattern where both alleles in a heterozygote are fully expressed, such as in $AB$ blood type.