Genetics: DNA Structure, Protein Synthesis, and Meiosis

Vocabulary-style flashcards covering DNA structure, replication, protein synthesis, and the stages/significance of meiosis as outlined in the lecture notes.

Nucleic acid

The macromolecule that holds our genetic material (DNA) and is made up of nucleotides.

Nucleotide

The monomer of nucleic acids consisting of three parts: a sugar (Deoxyribose or Ribose), a phosphate, and a nitrogen base.

Chromosome

Tightly coiled strands of DNA; humans have 23 pairs for a total of 46.

Gene

A section of DNA that has instructions to code for a protein.

Complementary base pairing rules

The principle that nitrogen bases bond only to their specific partner: Adenine (A) with Thymine (T) in DNA, and Cytosine (C) with Guanine (G).

Double helix

The structure of DNA described as a twisted ladder where sugar and phosphate form the backbone and nitrogen bases bond in the middle.

DNA Replication

The process occurring during the S Phase of Interphase that ensures each new cell has the same DNA as the original cell.

Semi-Conservative Replication

The replication process where each newly synthesized double helix is a combination of one "old" original strand and one "new" strand.

Central dogma

The concept that genetic information flows from DNA to RNA to protein.

Transcription

The process of carrying the code/instructions out of the nucleus by copying DNA into a complementary strand of mRNA.

Translation

The process of interpreting the RNA message into a polypeptide to make a protein, occurring at the ribosomes.

mRNA (messenger RNA)

The type of RNA that copies instructions in DNA and carries them to the ribosomes in the cytoplasm.

tRNA (transfer RNA)

The type of RNA that binds and carries specific amino acids to the ribosome.

rRNA (ribosomal RNA)

The type of RNA that, along with proteins, makes up the ribosome and helps catalyze the formation of peptide bonds.

Codon

A set of 3 nucleotides on the mRNA.

Anticodon

A set of 3 "complementary" nucleotides on tRNA.

Epigenetics

The study of heritable changes in gene expression that do not affect the actual DNA sequence.

Somatic cells

Body cells that are diploid ($2n$), such as blood cells or muscle cells.

Gametes

Sex cells (egg and sperm) that are haploid ($n$).

Autosomes

Chromosomes that carry traits making you who you are, specifically the 1st 22 pairs in humans.

Sex chromosomes

The 23rd pair of chromosomes (X or Y) that determine biological sex.

Karyotype

A diagram that shows the number and visual appearance of the chromosomes in a cell.

Meiosis

The process of cell division that makes haploid gametes in the gonads.

Homologous chromosomes

Chromosome pairs that have the same types of genes, with one coming from the mother and one from the father.

Sister chromatids

Two identical copies of the same chromosome.

Crossing over

A process occurring during Prophase I where homologous chromosomes swap pieces of DNA, creating new combinations of genes.