Honors Biology Summative Flashcards: Central Dogma & Meiosis

A comprehensive vocabulary set covering DNA/RNA structure, replication enzymes, protein synthesis, gene expression, and meiosis-related genetic diversity based on the Honors Biology study guide.

$DNA$ (Deoxyribonucleic Acid)

A double-stranded helix structure that stores genetic information using deoxyribose sugar and phosphate groups.

Nucleotide

The building block of nucleic acids, consisting of a deoxyribose or ribose sugar, a phosphate group, and a nitrogen base.

$DNA$ Bases

Adenine ($A$), Thymine ($T$), Cytosine ($C$), and Guanine ($G$).

Base Pairing Rules ($DNA$)

$A$ pairs with $T$, and $C$ pairs with $G$ via hydrogen bonds.

$RNA$ (Ribonucleic Acid)

A single-stranded nucleic acid that contains ribose sugar and uses Uracil ($U$) instead of Thymine ($T$).

$mRNA$ (Messenger RNA)

The type of $RNA$ that carries instructions from $DNA$ in the nucleus to the ribosome.

$tRNA$ (Transfer RNA)

The type of $RNA$ that brings specific amino acids to the ribosome for protein assembly.

$rRNA$ (Ribosomal RNA)

The type of $RNA$ that physically makes up the structure of ribosomes.

Sugar-phosphate backbone

The structural 'sides' of the $DNA$ ladder, composed of alternating sugars and phosphate groups.

Hydrogen bonds

The chemical bonds that hold nitrogenous base pairs together in the middle of a $DNA$ molecule.

Semi-Conservative Replication

The process where each new $DNA$ molecule consists of one original parent strand and one newly synthesized strand.

Helicase

An enzyme that 'unzips' $DNA$ by breaking hydrogen bonds, creating a replication fork.

Primase

An enzyme that builds short $RNA$ primers to provide a starting point for $DNA$ Polymerase.

DNA Polymerase

An enzyme that builds the new $DNA$ strand by adding nucleotides, working only in the $5' \rightarrow 3'$ direction.

Okazaki Fragments

Small sections of $DNA$ synthesized on the lagging strand.

DNA Ligase

An enzyme that 'glues' Okazaki fragments together on the lagging strand.

Histones

Proteins that $DNA$ wraps around to begin the packaging process inside eukaryotes.

Nucleosomes

Structures formed by $DNA$ and histones, often described as 'beads on a string'.

Chromatin

Coiled nucleosomes that further condense to form chromosomes.

Gene

A specific segment of $DNA$ that contains the instructions required to build a protein.

Gene Expression

The process by which different genes are turned on or off to create specialized cell types like skin or muscle cells.

Transcription

The process of making $mRNA$ from a $DNA$ template, occurring in the nucleus using $RNA$ Polymerase.

Codon

A sequence of three bases on $mRNA$ that specifies a single amino acid.

AUG

The specific start codon on $mRNA$ that initiates translation.

Anticodon

A three-base sequence on $tRNA$ that is complementary to an $mRNA$ codon.

Translation

The process of building proteins at the ribosome using $mRNA$, $tRNA$, and amino acids.

Introns

Noncoding regions of pre-$mRNA$ that are removed during $RNA$ processing.

Exons

Coding regions of $mRNA$ that remain and are spliced together to leave the nucleus.

Central Dogma

The fundamental concept describing the flow of genetic information: $DNA \rightarrow RNA \rightarrow Protein$.

Meiosis

A type of cell division that results in four genetically unique haploid ($n$) gametes.

Diploid ($2n$)

A cell containing two complete sets of chromosomes; in humans, this number is $46$.

Haploid ($n$)

A cell containing a single set of chromosomes; the state of gametes after meiosis.

Crossing Over

The exchange of genetic material between homologous chromosomes during Prophase I, creating new gene combinations.

Independent Assortment

The random alignment of homologous chromosomes during Metaphase I, contributing to genetic diversity.

Random Fertilization

The concept that any sperm can fertilize any egg, resulting in millions of possible genetic combinations.