Selective Breeding: Advantages, Disadvantages

• Selective breeding is the intentional breeding of organisms to pass on selected genetic traits and produce desirable traits.

Plant Selective Breeding

• Crop advantages include higher yields, disease resistance, insect pest damage resistance, hardiness, and better nutrient balance.

Animal Selective Breeding

• Since the 1950s, artificial insemination has become widely available for livestock
• Semen from prized bulls can fertilize thousands of cows via artificial insemination.
• Advantages include increased meat, milk, egg production, better fur, more offspring, increased disease resistance, and hardiness.
• Reasons to limit/stop selective breeding: loss of species variety, no control over mutations, animal discomfort, offspring with different traits, genetic depression, and environmental risks.

Genetic Modification

• Recombinant DNA is DNA formed by combining genetic material from different sources.
• Recombinant refers to containing genetic material from different sources.
• Cloning is the process of producing genetically identical copies of organisms or cells.
• Foreign DNA is from a different source than the organism.
• Vector DNA is a DNA molecule carrying foreign genetic material into a cell.
• Bacteria have chromosomal DNA and smaller circular DNA called plasmids.
• Plasmids are used in GM because they contain the same genetic material as chromosomal DNA and are self-replicating.
• Restriction endonucleases (enzymes) cut DNA molecules at specific points.
• Ligases (DNA ligases) join the cut ends of DNA molecules.
• Sticky ends are more useful because they ensure the DNA fragment is inserted correctly.
• A vector transfers a gene from any cell into a bacterium by inserting the gene into a plasmid.
• Bacteriophage: A virus that attacks a bacterium and injects its own DNA causing the bacterium to produce many virus particles.

Uses of GM Animals

• GM can improve animals for making human proteins, increased production of milk and meat, increased resistance to disease and harsh temperatures and production of organs for transplantation

Uses of GM Plants

• GM improves plants through extended shelf life, herbicide/freezing/pest/pathogen resistance, increased vitamin production, heat/drought/salt resistance, and better nutrient balance.

Genetic Modification Uses

• Genetic modification is used for human insulin production (previously from animals).
• Enzymes made by GM can work at higher temperatures for washing powders.
• The food industry uses GM in reactions converting sugars (glucose to fructose).
• GM bacteria produce human growth hormone for children lacking it.
• Bovine Somatotropin (growth hormone in cattle) increases milk and meat production from cattle from hormones made by GM.
• Human vaccines use GM to create antigens in bacteria that are injected, resulting in antibody production

Osmosis, Diffusion & Active Transport

• In biology, transport refers to the act or the means by which a molecule or ion is moved across the cell membrane or via the bloodstream.
• Passive transport does not require energy.
• Active transport requires energy.

Diffusion

• Diffusion is the movement of a substance from an area of high concentration to an area of low concentration
• Diffusion rate increases with a steeper concentration gradient and larger surface area to volume ratio.
• Diffusion rate decreases with greater distance.
• Diffusion rate increases at higher temps. This is because increased temperature will cause increased kinetic energy.

Osmosis

• Osmosis involves the diffusion of water.
• Semipermeable/selectively permeable/partially permeable membranes allow liquids or gases to pass through.
• Water moves from high to low concentration to balance concentrations in osmosis.
• Plasmolysed: Shrunken or reduced, caused by decreased pressure.
• Flaccid: Soft or loose, caused by equal pressure.
• Turgid: Swollen, packed, or condensed, caused by increased pressure.

Active Transport

• Active transport occurs when a cell intakes a substance against the concentration gradient.
• Active transport is often explained as a pumping action.
• Pumps are large proteins located in the cell membrane and are driven by ATP.
• Glucose and amino acids are often transported into cells against their concentration gradient, using active transport.
• Active transport uses transporter proteins (pumps) in the cell membrane.
• The protein pump needs energy in order to change shape.

Explore selective breeding in plants and animals, including artificial insemination for livestock. Understand the advantages like higher yields and disease resistance, as well as the limitations, such as loss of species variety and environmental risks. Definition of Recombinant DNA.