Question

What are nucleic acids/nucleotides? o Overall structure (what are the 3 subunits of nucleotides?) o What types of nucleic acids are there?

· How do nucleotides/bases pair up in DNA (complementary base pairs)?

· What is genome, chromosome, gene, mutation, exon, intron, and locus?

· What is gene expression? What is made during transcription? What is made during translation? What does RNA polymerase do? What does a ribosome do?

· How are DNA and RNA similar? How are they different?

· How do nucleotides/bases pair up in RNA (complementary base pairs)?

· What are mutations? Point mutations vs. frameshift mutations?

· What is biotechnology? What are the four steps of biotechnology? What do restriction enzymes do? What does Polymerase Chain Reaction (PCR) do? What is a plasmid?

· What is genetic engineering? · What is gene therapy?

· What is DNA Fingerprinting?

· How do prokaryotic cells divide? What is binary fission?

· How do somatic eukaryotic cells divide?

· How do gametes (sperm/egg cells) divide?

· What are the stages of mitosis? What happens in each stage?

· What are the stages of meiosis? What happens in each stage?

· What are the stages of interphase? What happens in each stage?

· How is DNA replicated?

· What are checkpoints? Where are they located in the cell cycle? Why are they important?

· Know the difference between sister chromatids and homologous chromosomes.

· What is cancer? What is contact inhibition?

· Know the difference between haploid and diploid.

· What is crossing over and when in the cell cycle does it occur?

· What is nondisjunction?

Answer 1

Nucleic acids are the biopolymers, or small biomolecules, essential to all known forms of life. The term nucleic acid is the overall name for DNA and RNA.

They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base.

The two main types of nucleic acids are DNA and RNA. Deoxyribonucleic acid (DNA) is a nucleic acid containing the genetic instructions used in the development and functioning of all known living organisms. The DNA segments carrying this genetic information are called genes. Ribonucleic acid (RNA) functions in converting genetic information from genes into the amino acid sequences of proteins. The three universal types of RNA include transfer RNA (tRNA), messenger RNA (mRNA), and ribosomal RNA (rRNA).

Only certain types of base pairing are allowed. This means Adenine pairs with Thymine, and Guanine pairs with Cytosine. This is known as the base complementary rule because the DNA strands are complementary to each other.

A genome is an organism’s complete set of DNA, including all of its genes. Each genome contains all of the information needed to build and maintain that organism.

Chromosome: a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.

Gene: a distinct sequence of nucleotides forming part of a chromosome, the order of which determines the order of monomers in a polypeptide or nucleic acid molecule which a cell (or virus) may synthesize.

Mutation: the changing of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations, caused by the alteration of single base units in DNA, or the deletion, insertion, or rearrangement of larger sections of genes or chromosomes.

exon: a segment of a DNA or RNA molecule containing information coding for a protein or peptide sequence.

Intron: a segment of a DNA or RNA molecule which does not code for proteins and interrupts the sequence of genes.

In genetics, a locus (plural loci) is a specific, fixed position on a chromosome where a particular gene or genetic marker is located.

Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein-coding genes such as transfer RNA (tRNA) or small nuclear RNA (snRNA) genes, the product is a functional RNA.

mRNA is made during transcription and protein is made during translation.

RNA polymerase is an enzyme that is responsible for copying a DNA sequence into an RNA sequence, during the process of transcription.

Ribosomes are a cell structure that makes protein. Protein is needed for many cell functions such as repairing damage or directing chemical processes.

DNA and RNA are similar in that both are ribonucleic acids that are found in cells and formed from nitrogenous bases. DNA and RNA are different in function: DNA stores the genetic material of an organism, while RNA conveys messages. Some of their nitrogenous bases are also different, as RNA contains uracil in place of DNA's thymine.

So in RNA the important base pairs are: adenine (A) pairs with uracil (U); guanine (G) pairs with cytosine (C).

Mutation are the  the changes of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations, caused by the alteration of single base units in DNA, or the deletion, insertion, or rearrangement of larger sections of genes or chromosomes.

Given below are the critical differences between the two types of mutations occurring in the base pairs of the DNA structure of a gene:

1. Point mutations happen when there is a replacement of one base pair from another, while Frameshift mutations occur when there is an insertion or deletion of the base pairs from the DNA structure.
2. Point mutations occur due to alterations in the single nucleotide, whereas frameshift occurs due to alterations in numerous nucleotides.
3. Point mutation brings changes in the structure of a gene because of the substitutions with another base pair, on the contrary, frameshift mutations change the number of nucleotides due to either insertions or deletions of the nucleotides.
4. Transitions and Transversions are the types of point mutations while Insertions and Deletions are the types of frameshift mutations.
5. Point mutations cause Sickle Cell Anemia as it brings changes in the structure of the gene, whereas frameshift mutations cause Tay-Sachs disease as it results in the changes in the number of base pairs in the DNA structure of a gene.

Biotechnology is a broad area of biology, involving the use of living systems and organisms to develop or make products.

The five steps are:

• Locating an organism with a specific trait and extracting its DNA.
• Isolating the desired gene that controls the trait.
• Designing a gene to express in a specific way.
• Transformation, inserting the gene into the cells of a crop plant.
• Plant breeding to create transgenic plants.

Restriction enzymes are used to cleave the vector in which the DNA fragment has to be inserted. This vector is further cloned into the host cells.

Amplification of DNA is done by PCR

Plasmid is a genetic structure in a cell that can replicate independently of the chromosomes, typically a small circular DNA strand in the cytoplasm of a bacterium or protozoan. Plasmids are much used in the laboratory manipulation of genes and can serve as a vector.

Genetic engineering, the artificial manipulation, modification, and recombination of DNA or other nucleic acid molecules in order to modify an organism or population of organisms. Gene therapy is a medical field which focuses on the utilization of the therapeutic delivery of nucleic acid into a patient's cells as a drug to treat disease.

DNA fingerprinting is a technique used especially for identification (as for forensic purposes) by extracting and identifying the base-pair pattern of an individual's DNA.