Biology: Intro to Biology and Genetics - Vocabulary Flashcards

Vocabulary flashcards covering key concepts from the lecture notes.

Cell

The basic unit of structure and function in all living things; life is made of one or more cells.

Prokaryotic cell

A simple cell type without a true nucleus; DNA is not enclosed in a nucleus.

Eukaryotic cell

A cell with a nucleus and membrane-bound organelles; DNA is located in the nucleus.

Organization (of living things)

Living things are arranged in an orderly way: cells, tissues, organs, organ systems.

Gene

A hereditary unit that passes from parent to offspring and is located on DNA.

DNA (deoxyribonucleic acid)

The information molecule that stores instructions for making proteins.

RNA (ribonucleic acid)

A nucleic acid that carries genetic information; uses ribose and contains uracil instead of thymine.

mRNA

Messenger RNA that carries genetic information from DNA to ribosomes for protein synthesis.

Ribosome

Cell structure where proteins are assembled during translation.

Codon

A three-base sequence on mRNA that codes for one amino acid.

Anticodon

Three-base sequence on tRNA that pairs with a codon during translation.

Transcription

The process of copying DNA into a complementary RNA sequence.

Translation

The process of assembling amino acids into a protein using mRNA as a template.

Amino acid

The building block of proteins.

Protein

A molecule that determines the structure and function of cells; made of amino acids.

Nucleus

Membrane-bound organelle that houses DNA in eukaryotic cells.

Chromosome

A DNA–protein structure that carries genes; visible during cell division.

Double helix

Shape of DNA consisting of two strands twisted like a spiral ladder.

Nucleotide

A building block of DNA consisting of a sugar, a phosphate group, and a base.

Sugar-phosphate backbone

The alternating sugar and phosphate groups that form the DNA/RNA backbone.

Adenine (A)

A nucleotide base that pairs with thymine in DNA (A–T).

Thymine (T)

A nucleotide base that pairs with adenine in DNA (A–T).

Cytosine (C)

A nucleotide base that pairs with guanine in DNA (C–G).

Guanine (G)

A nucleotide base that pairs with cytosine in DNA (C–G).

Chargaff's rule

In DNA, the amounts of A pair with T and G pair with C; varies among species.

Mutation

A change in the DNA sequence; can affect the protein produced.

Substitution

A mutation where one base is replaced by another.

Insertion

A mutation where one or more bases are added.

Deletion

A mutation where one or more bases are removed.

Frameshift

A mutation where insertions or deletions alter the reading frame.

Trisomy

A chromosomal condition with an extra chromosome (47 total).

Down syndrome

Trisomy 21; a common chromosomal disorder.

Edwards syndrome

Trisomy 18; a chromosomal disorder.

Mitosis

Cell division producing two genetically identical diploid daughter cells.

Interphase

Phase of the cell cycle when the cell grows and DNA is replicated.

Prophase

Chromosomes condense and the nuclear envelope breaks down; spindle forms.

Metaphase

Chromosomes line up at the cell's equator with spindle fibers attached.

Anaphase

Sister chromatids separate and move to opposite poles.

Telophase

Chromosomes reach the poles; nuclei re-form.

Cytokinesis

Cytoplasm divides, forming two separate daughter cells.

Diploid

Two complete sets of chromosomes (2n).

Haploid

One complete set of chromosomes (n).

Meiosis

Cell division that produces gametes (four haploid cells) through two divisions.

Gamete

Sex cells (sperm and egg) produced by meiosis.

Crossing over

Exchange of genetic material between homologous chromosomes during meiosis I.

Meiosis I

First meiotic division; homologous chromosomes separate.

Meiosis II

Second meiotic division; sister chromatids separate.

Punnett square

Diagram to predict genotype and phenotype ratios in a cross.

Genotype

The genetic makeup of an organism (the alleles it carries).

Phenotype

The observable characteristics of an organism.

Allele

A variant form of a gene at a specific locus.

Dominant

An allele that is expressed in the phenotype even if only one copy is present.

Recessive

An allele that is expressed only when two copies are present.

Homozygous

Having two identical alleles for a gene.

Heterozygous

Having two different alleles for a gene.

Independent assortment

Alleles on different chromosomes assort independently during gamete formation.

Law of segregation

During gamete formation, two alleles for a gene separate so each gamete receives one.

Law of dominance

A dominant allele masks the effect of a recessive allele in a heterozygote.

Inheritance

The passing of genetic information from parents to offspring.

Inherited characteristics

Traits determined by genes passed from parent to offspring.

Acquired characteristics

Traits acquired due to environment or experience, not genetic inheritance.

Karyotype

A chart showing an individual's complete set of chromosomes arranged in pairs.

Mendelian genetics

Study of how traits are inherited via dominant and recessive alleles (Mendel's laws).