Biology - Ch 12 and 13 Review

Frederick Griffith

Discovered transformation during an experiment that involved injecting mice with smooth S cells, rough R cells, heat-killed S cells, and heat-killed S cells with living R cells.

The Hershey-Chase experiment

confirmed that DNA is the genetic material because only radiolabeled DNA could be found in bacteriophage-infected bacteria

Rosalind Franklin

Woman who used a technique called X-Ray diffraction to study DNA, she provided Watson and Crick with key data about DNA; demonstrated that DNA is in the form of a helix

Watson and Crick

discovered the structure of DNA; published their 3D model of the DNA double helix

Nucleotide

structure of DNA

DNA is like a ladder or spiral staircase. The outside is made of a sugar-phosphate backbone with alternating sugars and phosphates and the inside "steps" are the nitrogenous bases.

Process of DNA replication

the DNA molecule separates into two strands, then produces two new complementary strands following the rules of base pairing. Each strand of the double helix of DNA serves as a template, or model, for the new strand.

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

Genes

DNA segments that serve as the key functional units in hereditary transmission.

mRNA

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome

tRNA

transfer RNA; type of RNA that carries amino acids to the ribosome

rRNA

ribosomal RNA; type of RNA that makes up part of the ribosome

Transcription

process in which part several segments of DNA serve as templates to produce complementary RNA molecules; process requires an enzyme called RNA polymerase

RNA polymerase

enzyme that binds to DNA during transcription and separates DNA strands, then uses one DNA strand as a template fro which to assemble nucleotides into a complementary strand of RNA

complimentary bases

A-T and G-C
Two strands that make up the double-helix

Erwin Chargaff

Discovered that DNA composition varies, but the amount of adenine is always the same as thymine and the amount of cytosine is always the same as guanine.

Ribosome

organelle that makes proteins

Nucleus

A part of the cell containing DNA and RNA and responsible for growth and reproduction

Introns

sequence of DNA that is not involved in coding for a protein

Exons

Coding segments of eukaryotic DNA.

What are the differences between DNA and RNA?

DNA: double stranded, has deoxyribose sugar, bases: A, T, G, C
RNA: single stranded, has ribose sugar, bases: A, U, G, C

Importance of DNA

stores info for traits, development and cell activities

Importance of RNA

the flow of genetic information in a cell is from DNA through RNA to proteins

What does mRNA do?

messenger, contains the information from DNA to make protein by translation

What does tRNA do?

It transfers amino acids to a growing protein chain on the ribosome.

what does rRNA do?

makes up ribosomes

Process of Transcription

RNA polymerase uses ATP to read the DNA strand and form an mRNA strand in the nucleus

Importance of transpiration

carries water to all the cells of the plant

Polypeptide

A polymer (chain) of many amino acids linked together by peptide bonds.

Genetic code

the ordering of nucleotides in DNA molecules that carries the genetic information in living cells

codon

A specific sequence of three adjacent bases on a strand of DNA or RNA that provides genetic code information for a particular amino acid

anticodon

a sequence of three nucleotides forming a unit of genetic code in a transfer RNA molecule, corresponding to a complementary codon in messenger RNA.

Translation

Process by which mRNA is decoded and a protein is produced

gene expression

process by which a gene produces its product and the product carries out its function

Mutation

a random error in gene replication that leads to a change

point mutaion

a mutation in which one nucleotide is substituted for another

Substitution

A mutation in which a nucleotide or a codon in DNA is replaced with a different nucleotide

Insertions

A mutation involving the addition of one or more nucleotide pairs to a gene.

Deletion

A change to a chromosome in which a fragment of the chromosome is removed.

Frameshift mutations

mutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide

Chromosome mutations

variations in the number and structure of chromosomes

Deletion

A mutational loss of one or more nucleotide pairs from a gene.

Duplication

repeats a segment

Inversion

inverted order of words in a sentence (variation of the subject-verb-object order)

Translocation

Change to a chromosome in which a fragment of one chromosome attaches to a nonhomologous chromosome.

Mutagens

A chemical or physical agent that interacts with DNA and causes a mutation.

polyploidy

condition in which an organism has extra sets of chromosomes

How can mutations be beneficial?

Mutations lead to genetic diversity. Genetic diversity provides variations in organisms that could lead to better fitness in an environment.

How can mutations be harmful?

Can cause diseases or abnormal changes physically like cancer

Can a mutations have no affect?

A mutation can have no effect on a person for example sample eye color. Eye color does not drastically affect a person.

Why is having mutations important for all life?

Mutations lead to genetic diversity. Genetic diversity provides variations in organisms that could lead to better fitness in an environment.

Gene regulation

ability of an organism to control which genes are transcribed in response to the environment

Operon

group of genes operating together

Repressor

A protein that binds to an operator and physically blocks RNA polymerase from binding to a promoter site

Promoter

specific region of a gene where RNA polymerase can bind and begin transcription

Transcription factors

Collection of proteins that mediate the binding of RNA polymerase and the initiation of transcription.

TATA Box

A promoter DNA sequence crucial in forming the transcription initiation complex.

Cell specialization

the process in which cells develop in different ways to perform different tasks

RNA interference

Blocking gene expression by means of an miRNA silencing complex.

Homeotic genes

Genes that determine basic features of where a body part is.

Homeobox genes

genes that code for transcription factors that activate other genes that are important in cell development and differentiation

Hox genes

series of genes that controls the differentiation of cells and tissues in an embryo

Environmental influences.

Factors such as air, water, soil, mineral, plant and animal resources

What is gene regulation?

the ability to turn genes on and off

How is prokaryotic and eukaryotic gene regulation different?

Prokaryotic transcription and translation occur simultaneously in the cytoplasm, and regulation occurs at the transcriptional level. Eukaryotic gene expression is regulated during transcription and RNA processing, which take place in the nucleus, and duri

Why is the environment important in gene regulation?

Changes in gene expression are themselves governed by changes in underlying gene regulatory mechanisms, which hold important clues to how social environmental effects arise and/or are maintained over time.