Biology content

• Axon = the long thin section of a neurone where the nerve impulses travel
• Homeostasis = the maintenance of a constant internal environment despite changes in the external environment
• Protein synthesis = the process of making proteins from amino acids
• Cytokinesis = the division of the cytoplasm into two daughter cells
• Mitosis = the stage of cell division that produces two genetically identical daughter cells
• Gamete = sex cell produced during meiosis
• Meiosis = the type of cell division that reduces chromosome number by half, producing four haploid gametes (eggs or sperm)
• Meiosis = the type of cell division that reduces chromosome number by half, producing four haploid gametes (sex cells)
• Hormones are chemical messengers secreted directly into the bloodstream to regulate metabolic processes throughout the body.
• Zygote = fertilised egg formed when an ovum is fertilised by a sperm
• Chromatid = one of the two strands formed when DNA replicates
• Sister chromatids = two identical copies of a chromosome joined together at the centromere
• The endocrine system is made up of glands that secrete hormones into the bloodstream which then travels around the body to target organs or tissues.
• Centrioles = structures made up of microtubules found near the nucleus which organise spindle fibres during mitotic cell division
• Prophase = first phase of mitotic cell cycle where nuclear envelope breaks down, spindle fibres form and chromatin condenses to become visible as chromosomes.
• The endocrine system is made up of glands that secrete hormones directly into the bloodstream.
• Metaphase = second phase of mitotic cell cycle where chromosomes line up along equatorial plane of cell
• Ovary = female reproductive organ where eggs develop
• Testes = male reproductive organs where sperm develop
• Endocrine glands include the pituitary gland, thyroid gland, adrenal glands, pancreas, ovaries/testes, and pineal gland.
• Examples of hormones include insulin, glucagon, growth hormone, cortisol, testosterone, estrogen, progesterone, melatonin, and thyroxine.
• Synapses = junctions between neurons where neurotransmitters pass from one neuron to another
• Anaphase = third phase of mitotic cell cycle where sister chromatids separate at centromere and move towards opposite poles of cell
• Spermatogenesis = process of sperm production
• Neurotransmitter = chemicals released at synapses which transmit signals across gaps called synaptic clefts
• Homologous pair = two chromosomes with similar genes but different alleles
• Axon = long projection of a nerve cell along which impulses travel away from the cell body
• Mitosis = process whereby a eukaryotic cell divides to produce two genetically identical daughter cells
• Amino acids are organic molecules containing amino (-NH2) and carboxyl (-COOH) groups attached to an asymmetric carbon atom.
• Cytokinesis = the final stage of mitosis where the cytoplasm divides to form two new cells
• Mitosis = process where cells divide to produce genetically identical daughter cells, occurs in somatic (body) cells
• Proteins have many functions including structural support, enzymes, transporting substances across membranes, signalling between cells, immune response, storage of nutrients, and movement.
• Meiosis = process where sex cells divide to produce haploid gametes with half the number of chromosomes as normal body cells
• Metaphase = second stage of mitosis where sister chromatids line up along metaphase plate (equator) ready for separation
• Enzyme-substrate complex forms when substrate binds with active site on enzyme.
• Anaphase = third stage of mitosis where sister chromatids are pulled apart by contraction of spindle fibres towards opposite poles of the cell
• Cytokinesis = stage of mitosis/meiosis where cytoplasm divides to form new cells
• Metaphase = second stage of mitosis where sister chromatids line up along the metaphase plate (equator) ready for separation.
• Anabolic pathways are those involved in building molecules from smaller units such as glucose synthesis from carbon dioxide and water.
• Anabolic reactions are those that require energy (ATP) and result in larger molecules being formed from smaller ones.