Generally, what is DNA?
DNA is what makes people who they are. DNA tells what color hair, eyes etc. Belong to you.
What makes up a nucleotide?
A sugar, phosphate, and nitrogenous base
What are the nitrogenous bases?
A basic compound that contains nitrogen, such as a purine or pyrimidine.
What is one of Chargaff's rules?
A=T and G=C
What did Franklin do?
Invented prototype X-ray
What did Watson & Crick contribute?
Wrote double helix and created a 3D model of DNA with cardboard and wire
The Double-Helix Model:
What does this model explain?
Chargaff's rule of base pairing and how two strands of DNA stay together.
What role do hydrogen bonds play in DNA?
They make up nitrogen bases, which hold together strands of DNA.
Define base pairing.
Principle that bonds in DNA can from only between A & T or between G & C.
Cells must be able to transport?
oxygen, water, waste product, glucose
What process moves these materials?
Through what does this process occur?
1 parent,offspring are genetically identical to 1 parent
Advantages? Fast, No sharing of genetic inheritance
Disadvantages? All offspring have same susceptibility to disease
Examples: Bacteria, Hydra Budding
Sexual: Two parents, Genetically distinct offspring
Advantages: Increase in diversity means population is able to resist disease and disturbance, New combinations may result in new species over time
Disadvantages: Sharing of genetic inheritance, have to find a mate.
Contain genetic information, the "recipe" for the body in the form of DNA
o Every cell in your body (except sex cells) contain the same genetic information
o Humans have 46 chromosomes
Discuss 1 way cells stop growing and dividing.
Cells will stop growing and dividing if mitosis stops. Mitosis allows cells to grow and divide through out the body, but without mitosis, cells won't be able to grow and divide.
What is cyclin?
Any of a number of proteins associated with the cycle of cell division that is thought to initiate certain processes of mitosis.
What controls all of the cell cycle?
Growth and division controls all of the cell cycle
Describe 2 functions of internal regulators.
They respond to events inside a cell and they allow the cell cycle to proceed only once certain processes have happened inside the cell.
Describe 2 functions of external regulators.
They respond to events outside the cell and they direct cells too speed up or slow down the cell cycle.
What are growth factors?
A substance that affects the growth of a cell or an organism.
List the 2 ways a cell can die.
Cell stops going through mitosis and or becomes tumorous.
Disintegration of cells into membrane-bound particles that are then eliminated by phagocytosis or by shedding.
The disease caused by an uncontrolled division of abnormal cells in a part of the body.
An abnormal mass of tissue
What are the 2 types of tumors?
Malignant tumors and benign tumors.
What are the effects of cancerous tumors?
It can cause metastasis or the spreading of cancer cells.
What causes cancer?
The sun/UV exposure, poor diet, genetics, tobacco, and other carcinogens are all examples of causes of cancer.
List some treatments for cancer.
Chemo therapy, radiation
People to remember
• Griffith (1928)
• Avery & colleagues (1944)
• Rosalind Franklin & M. Wilkins (1950)
• Chargaff (1951
• James Watson & Francis Crick (1953)
What did we know about DNA?
• We knew that it was composed of chains of four nucleotides - containing four different nitrogenous bases.
What is a nucleotide?
• Nucleotides are composed of 3 parts:
o Nitrogenous Base
o 5-carbon sugar
o Phosphate group
Rule of complementary
• The "functional unit" of DNA is the gene.
• A gene is the sequence of DNA that contains the information required to make one protein.
Prokaryotic DNA Replication
• Prokaryotic DNA Replication
o DNA is circular
o Replication begins at a single location an proceeds in both directions until fully copied
Eukaryotic DNA Replication
• Eukaryotic DNA Replication
o Begins at several origins of replication
o Advantage: Faster copying of the DNA
Where is DNA found in the cell?
Is single stranded
o Uses ribose sugar instead of deoxyribose sugar
o has four different nitrogenous bases
Carries instructions for polypeptide to the ribose
Factory where polypeptides are assembled
• Monomers of a protein
Carries amino acids and matches them to the corresponding code on the mRNA
One set of three RNA letters is called a codon.
o Sickle Cell Anemia
• Red blood cells have a crescent moon shape and are not efficient at transporting oxygen in the body
• Results from a single point mutation which changes a single amino acid in the hemoglobin protein
• Helpful (although maybe not for humans)
o Chemical resistance in insects
o Antibiotic resistant bacteria
• Extra sets of chromosomes
• Tend to be stronger more productive plants
What is the role of chromosomes in cell division?
Chromosomes make it possible to separate DNA precisely during cell division
Genetics' bundled into packages of DNA
Explain prokaryote's genetic info.
lack nuclei and many of the other organelles found in eukaryote's. Their DNA is found in the cytoplasm along with most of the contents of the cell. Most prokaryote's contain a single, circular DNA chromosome that contains all, or nearly all, of all the cell's genetic information.
Substance found in eukaryotic chromosomes that consists of DNA tightly coiled around histones, a type of protein
A structural unit of a eukaryotic chromosome, consisting of a length of DNA coiled around a core of histones
What happens during the cell cycle?
During the cell cycle, a cell grows, prepares for division, and divides to form two daughter cells
Define binary fission
The process of cell division in prokaryotes is a form of asexual reproduction known as binary fission
List the 4 phases of the cell cycle.
G1 Phase: Cell Growth
S Phase: DNA Replication
G2 Phase: Preparing for Cell Division
M Phase: Cell Division
Period of the cell cycle between cell divisions
Explain the G1 phase
In this phase, cells increase in size and synthesize new proteins and organelles
Explain the S phase
In this phase, new DNA is synthesized when the chromosomes are replicated
Explain the G2 phase
In this phase, many of the organelles and molecules required for cell division are produced
Explain the M phase
In this phase, two daughter cells are produced
What is Mitosis?
Part of eukaryotic cell division during which the nucleus divides
What is Cytokinesis?
Division of the cytoplasm to form two separate daughter cells
An unborn or un-hatched offspring in the process of development.
The process by which cells become progressively more specialized; a normal process through which cells mature.
(Of an immature or stem cell) Capable of giving rise to any cell type or (of a blastomeric) a complete embryo
Blastocyst - One layered developing embryo with cavity of blastula
(Of an immature or stem cell) Capable of giving rise to several different cell types.
What are stem cells?
Stem cells are a class of undifferentiated cells that are able to differentiate into specialized cell types. Commonly, stem cells come from two main sources:
Where are stem cells found?
Most tissues in the body have their own stem cells, which have the ability to produce mature cells of that specific tissue. Their job is to replenish cells of that tissue when old cells die. Muscles, skin, nerves, and the liver are just a few examples of tissues and organs where stem cells can be found. The type of stem cell that produces blood cells (also called "hematopoietic stem cells") is mostly found in the bone marrow. A small number of hematopoietic stem cells can also be found in the bloodstream.
Ability of a single stem cell to develop into more than one cell type of the body.
Explain some potential benefits
Being able to duplicate parts of the body if not a whole knew body known as cloning. (Not positive)?
What are the issues behind using embryonic cells?
There limited in number and don't have a long storage life. They are also very difficult to control.
What are polypeptides?
A linear organic polymer consisting of a large number of amino-acid residues bonded together in a chain, forming part of (or the whole of) a protein molecule
List the 4 RNA bases.
Adenine, guanine, thymine, and cytosine
How many different amino acids are there?
Why are 3 bases needed to code for 1 amino acid?
3 bases are needed to fulfill the code
A sequence of three nucleotides, which together form a unit of genetic code in a DNA or RNA molecule.
What are stop codons?
A STOP codon marks the end of a segment of DNA that is to be transcribed
What role do ribosomes play?
Ribosomes travel along strands of mRNA and provide sites for tRNA to attach according to the codon sequence.
Translation is the process by which messenger RNA used as a template to make the corresponding protein.
List the general steps to translation.
Initiation, elongation, and termination
What is an 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
At what point do all RNAs come together?
They all come together in the cytoplasm.
State 1 fact about proteins
Protein is what makes up your ligaments, tendons, muscles, hair, nails, skin, teeth, tissue, organs, and bones. About half of the non-water mass of your body is made up of protein.
What is the central dogma of molecular biology
States that such information cannot be transferred back from protein to either protein or nucleic acid.
The passing on of physical or mental characteristics genetically from one generation to another.
The study of heredity and the variation of inherited characteristics.
Who founded the science of genetics?
When sperm meets up with a woman's egg the sperm is fertilizing the woman's egg
A distinguishing quality or characteristic, typically one belonging to a person.
What are "true" breeding plants?
A plant, that when self-fertilized, only produces offspring with the same traits. The alleles for these type of plants are homozygous.
Explain Mendel's cross pollination
Mendel's cross-breeding of common pea Mendels cross breeding of common pea plants showed certain traits show up in offspring without blending parent characteristics.
Explain P and F1 generations
P generation is the parental generation in the cross pollination between two true-breeding plants that differ in a particular trait.
F1 is (first filial) generation the hybrid offspring produced in the cross pollination of P generation plants.
A unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the...: "proteins coded directly by genes"
One of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.
Explain principle of dominance.
The Principle Of Dominance states that some alleles are dominant and some alleles are recessive.
Describe how Mendel made F2 plants.
Because the possible combinations are DD, Dr, rD, and rr. When a dominant gene is present (D), then that gene is selected. The plants only have a one in four chance of getting a rr combo (r being recessive). It must inherit two recessive genes to display that trait.
Define and explain segregation
States that allele pairs separate or segregate during gamete formation, and randomly unite at fertilization.