Biology Photosynthesis vs. Cellular Respiration

Interrelation of Photosynthesis and Cellular Respiration

• Photosynthesis reduces atmospheric carbon dioxide, while cellular respiration emits carbon dioxide back into the atmosphere.
• Both processes are essential for maintaining the carbon cycle in ecosystems.

Substances Used by Green Plants

• Green plants continuously utilize carbon dioxide and oxygen throughout a 24-hour period.
• These gases are critical for their metabolic processes and growth.

Differences Between Photosynthesis and Cellular Respiration

• Photosynthesis captures and releases energy, facilitating the creation of glucose.
• Cellular respiration processes stored energy from glucose, producing ATP for cellular activities.

Description of Cancer

• Cancer is characterized by uncontrolled cell growth.
• It is caused by mutations in genes that regulate the cell cycle, leading to abnormal cell division.

Homologous Chromosomes in Meiosis

• During prophase 1 of meiosis, homologous chromosomes undergo crossing-over.
• This process allows for the exchange of alleles, increasing genetic diversity in gametes.

Events from Mitosis vs. Meiosis

• Mitosis produces daughter cells that are genetically identical to the parent cell.
• Meiosis, in contrast, results in genetically diverse gametes due to crossing-over and independent assortment.

Determinants of Individuality in Organisms

• An organism's individuality is biologically determined by the sequence of nitrogenous bases in its DNA.
• This genetic code dictates all aspects of development and functioning.

DNA Sample Composition

• If a DNA sample contains 20% thymine (T), it logically contains 30% cytosine (C).
• This is a reflection of Chargaff's rules regarding base pairing in DNA.

Products of DNA Replication

• DNA replication results in two molecules, each consisting of one original strand and one newly synthesized strand.
• This semi-conservative mechanism ensures genetic fidelity.

Timing of DNA Replication

• DNA replication occurs before cell division.
• This timing guarantees that each daughter cell receives a complete set of DNA instructions.

Cloning Human Genes in Bacteria

• Bacteria can produce human proteins because the basic components of DNA are conserved across species.
• This capability facilitates significant advances in medical and biotechnological applications.

Amino Acids Coded by DNA Segments

• A specific DNA segment can code for 4 amino acids.
• The sequence of nucleotides within the gene ultimately determines the amino acid sequence of the resulting protein.

Caution with New Synthetic Chemicals

• The introduction of a new synthetic chemical necessitates careful societal scrutiny due to potential harmful effects.
• Risks may include health issues for individuals and adverse environmental impacts.