Unit 2 & 3: Central Dogma, Cell Cycle, & Heredity

Mitosis

The process where a single cell divides into two identical daughter cells for growth and repair.

Cell Differentiation

The process by which a general, unspecialized cell becomes a specialized cell with a specific function.

Gene Expression

The process by which information from a gene is used to synthesize proteins, dictating cell traits.Certain genes are turned on while others are still turned off.

Cancer (Uncontrolled Cell Growth)

A disruption in the cell cycle where cells divide continuously without stopping, often caused by unregulated proteins.

Interphase

The longest part of the cell cycle -- all the checkpoints and growth needed for cell division.

S Phase

Part of interphase where DNA replicates or copies itself.

Central Dogma

The universal flow of genetic information in a cell

Transcription

The process where a segment of DNA is copied into a complementary strand of mRNA inside the nucleus.

mRNA (Messenger RNA)

The temporary RNA molecule that carries the genetic recipe from the DNA out to the ribosome.

Translation

The process where the ribosome reads the mRNA code to string amino acids together into a functional protein.

tRNA (Transfer RNA)

The delivery truck molecule that brings specific amino acids to the ribosome by matching its anti-codon to the mRNA codon.

Codon

A specific sequence of three bases on mRNA that codes for one single amino acid.

Amino Acid

The basic building block monomer that chains together to build a protein.

Asexual reproduction

One an organism/cell can reproduce on its own. Ex

Sexual Reproduction

DNA from two individuals needed to reproduce.

Meiosis

A specialized type of cell division that creates four unique gametes (sex cells) with half the original DNA.

Fertilization

The joining of an egg and a sperm cell to restore the full set of DNA in offspring.

Gamete

A reproductive sex cell (sperm or egg).

Mutation

A permanent change in the DNA sequence, which can happen during replication or due to environmental factors (like radiation).

Genetic Recombination (Crossing Over)

The swapping of genetic material between matching chromosomes during meiosis, creating new trait combinations.

Mendelian Inheritance (Monohybrid)

Simple dominance where one allele completely hides another.

Co-dominance

An inheritance pattern where both traits show up clearly at the same time. (Ex

Incomplete Dominance

An inheritance pattern where traits blend together into a new, middle phenotype. (Ex

Multiple Alleles

When a gene has more than two possible variations (e.g., ABO Blood types).

Sex-linked Inheritance

Traits carried specifically on the X or Y sex chromosomes. (we focus on X)

Polygenic Trait

A trait controlled by the interaction of multiple genes, resulting in a wide range of outcomes (like skin color or height).

Phenotype

The physical, observable appearance of a trait.

Genotype

The actual genetic code or allele combination (e.g., Bb)

Dominant

The allele/trait that is "stronger" or will show even if there is only one. The big letter (B).

Recessive

The allele/trait that can hide if there is only one. There must be two for the trait to be observable. The little letter (b).

Heterozygous

When there is one dominant allele and one recessive allele. (Bb)

Homozygous

When both alleles look the same. Both big or both little. (BB or bb)

Mutation in DNA

A permanent change in the DNA sequence that can affect genetic information inherited by the next generation.

Mutation in RNA

A change in the RNA sequence that can affect the produced protein but is not inherited, as RNA is transitory and synthesized from DNA.

Autosomal Chromosomes

Chromosomes that do not determine the sex of an individual and are present in pairs in both males and females (e.g., chromosomes 1-22 in humans).

Sex Chromosomes

Chromosomes that determine the sex of an individual, typically referred to as the X and Y chromosomes in humans; females have two X chromosomes (XX), and males have one X and one Y chromosome (XY).

Specialized Cells

Cells that have differentiated to perform a specific function, such as nerve cells for signal transmission or muscle cells for contraction.

Gene Cells

Cells that carry the genetic information and are involved in gene expression, leading to the synthesis of proteins that dictate cell traits.

DNA

Double-stranded, stores genetic information. Nitrogenous base pairs A&T, C&G.

RNA

Single-stranded, transmits genetic information. Nitrogenous Base Pairs A&T, C&G.