ch 16 DNA Replication and Genetics

This set of flashcards includes key vocabulary terms and definitions related to DNA replication and genetics, helping reinforce understanding of the concepts covered in lectures.

DNA

The genetic material that carries information necessary for the growth, development, and reproduction of organisms.

Transformation

_______ is the change in genotype and phenotype working with two strains of bacterium one pathogenic and one harmless

Fredrick Griffith

_______ discovered genetic role of DNA working with two bacterium strains and mixing heat

R strain bacterium

______ is the “Rough” strain that is harmless and nonpathogenic

S strain bacterium

______ is the “smooth” strain that is pathogenic and causes illness, kills the mice

DNA

Based on Griffith’s experiment, what enzyme was the cause for killing the mouse?

How did DNA kill the mouse in the transformation experiment?

Transformed the R strain to the S strain when DNA injected

S^ 35

______ identifies proteins that is located on the outside, cystine

^32P

_______ found in the backbone of DNA to identify DNA

Erwin Chargoff

_______ reported the nitrogenous bases Adenine and Thymine bind and Guanine and Cytosine bind

Wilkins and Franklin

__________ used X ray crystallography to study molecular structure, producing a picture of DNA molecule suggesting double helix

Purines

A or G

Pyrimidine

C or T

Semiconservative model

Watson and crick’s model: ____________ that predicts when a double helix replicates there is an old strand and a new strand

The Most Beautiful Model

Experiment: __________ by Matthew measles on and Franklin Stahl that supported the semiconservative model

Replication

The process of copying DNA before cell division.

Transformation

A change in genotype and phenotype due to the assimilation of foreign DNA.

Bacteriophage

A virus that infects bacteria, consisting of DNA enclosed by a protein coat.

Chargaff’s Rules

In any species, the number of adenine (A) and thymine (T) bases is equal, and the number of guanine (G) and cytosine (C) bases is equal.

X-ray Crystallography

A technique used to determine the atomic structure of a crystal, used by Rosalind Franklin to study DNA.

Watson-Crick Model

The model of DNA structure proposing that DNA consists of two antiparallel strands forming a double helix.

Semiconservative Replication

The method of DNA replication where each daughter molecule retains one original strand.

Origins of Replication

Specific sites where DNA replication begins, creating a replication bubble.

Replication Fork

Y-shaped region at the ends of replication bubbles where DNA strands are unwound.

Helicase

An enzyme that unwinds the DNA double helix at the replication fork.

DNA Polymerase

The enzyme responsible for synthesizing new strands of DNA by adding nucleotides.

Okazaki Fragments

Short segments of DNA synthesized on the lagging strand during DNA replication.

Leading Strand

The strand of DNA that is synthesized continuously in the direction of the replication fork.

Lagging Strand

The strand of DNA that is synthesized in short segments away from the replication fork.

Telomeres

Special nucleotide sequences at the ends of linear DNA that protect genes from erosion.

Telomerase

An enzyme that extends telomeres in germ cells, preventing the loss of important genes.

Nucleosome

The basic unit of DNA packing, consisting of a segment of DNA wound around a core of histone proteins.

Euchromatin

Loosely packed chromatin that is accessible for transcription.

Heterochromatin

Tightly packed chromatin that is generally inactive in transcription.

Single-Strand Binding Proteins

Proteins that stabilize unwound single strands of DNA during replication.

Topoisomerase

Enzymes that relieve the strain of twisting DNA ahead of the replication fork.

Primase

An enzyme that synthesizes a short RNA primer needed for DNA polymerase to initiate synthesis.

Deoxyribonucleoside Triphosphates (dNTPs)

The building blocks of DNA, released as two phosphate groups when added to a growing DNA strand.

Nucleotide Excision Repair

A DNA repair mechanism that removes damaged sections of DNA.

Mismatch Repair

A process in which enzymes correct incorrect base pairing in DNA.

Gene Expression

The process by which information from a gene is used to synthesize a functional gene product.

Mutations

Permanent changes in the DNA sequence that may lead to variations in traits.

Polymerase Chain Reaction (PCR)

A technique used to amplify small segments of DNA for study.

Spontaneous Mutations

Changes in DNA that occur without external influence, often during DNA replication.

Proteins

Molecules composed of amino acids that perform a variety of functions in a cell.

Gene Regulation

The mechanisms that act to increase or decrease the production of specific gene products.

Inheritance

The process by which genetic information is passed from parents to offspring.

Cell Cycle

The series of phases that a cell goes through in order to grow and divide.

Zygote

The initial cell formed when two gametes fuse during fertilization.

Genetic Variation

The diversity in gene frequencies within a population, often caused by mutations.

Biological Evolution

The change in the heritable traits of biological populations over successive generations.

Phenotype

The observable physical and physiological traits of an organism determined by its genotype.