Unit 7 Bio

Transformation

When a cell takes in external DNA, causing its traits to change.

Okazaki Fragments

Short pieces of DNA that are made on the lagging strand during DNA replication.

Leading Strand

The strand that is synthesized continuously as the DNA polymerase moves in that same direction.

Lagging Strand

The strand that is synthesized discontinuously, and DNA is built in short segments.

Nucleotides

Monomer of DNA and RNA.

Amino Acids

Monomer of proteins.

Antiparallel

How two strands of DNA run in opposite directions.

Purine

Single ringed nitrogenous base.

Pyrimidine

Double ringed nitrogenous bases.

Telomere Erosion

The gradual shortening of the telomere, which are protective caps at the end of each chromosome.

Transcription

The synthesis of RNA using a DNA template.

Translation

The synthesis of a polypeptide using the genetic info encoded in a mRNA molecule.

Central Dogma of Genetics

The flow of genetic information from DNA to RNA to proteins.

Template strand

The strand used to produce an mRNA transcript.

Start Codon

The three nucleotides that signal the beginning of translation (typically AUG).

5’ cap

Modified form of a guanine nucleotide that protects the mRNA and helps ribosomes attach.

Poly-A-Tail

About 50-250 adenine nucleotides are added to protect the mRNA and help it leave the nucleus.

Mitosis

The process of nucleus division essential for growth and repair.

Interphase

The phase where the cell grows and prepares for mitosis, including stages G1, S, G2, and G0.

Prophase

The phase in mitosis where chromosomes begin to condense and the nuclear envelope disappears.

Metaphase

The phase where chromosomes line up at the middle of the cell.

Anaphase

The phase in which sister chromatids are pulled apart at the centromere.

Telophase

The phase where chromosomes are at opposite ends of the cell and the nuclear envelope forms around them.

Cytokinesis

The process of dividing the cytoplasm to form two separate cells.

Meiosis

The process that produces sex cells (gametes) with half the chromosomes.

Law of Segregation

Every organism has two alleles for a trait, which separate during meiosis.

Law of Dominance

One allele is dominant over the other recessive allele.

Law of Independent Assortment

States that different traits are passed independently from parent to offspring.

Dominant Alleles

Alleles that mask the expression of recessive alleles.

Recessive Alleles

Alleles that must have a homozygous combination to be expressed.

Punnett Squares

A tool to predict the genotype and phenotype of offspring based on Mendelian genetics.

Genetic Disorders

Conditions resulting from abnormalities in the genetic material.

Gene Therapy

A technique aimed at correcting defective genes responsible for diseases.

Genetic Engineering

Manipulation of a cell’s genetic material through recombinant DNA technologies.

Human Genome Project

Initiative aimed at mapping the entire gene sequence.