Cell Growth and Division Process

The process of cell division involves several carefully coordinated stages, beginning with DNA replication in the non-dividing cell. During this phase, the cell's genetic material is duplicated to ensure each daughter cell will receive a complete set of chromosomes.

Before division occurs, cells must grow and increase their cellular components, including mitochondria and ribosomes. This preparation ensures that each daughter cell will have adequate resources to function independently after division.

The actual division process involves precise chromosome alignment and separation, followed by the formation of new nuclear membranes and cell membranes. This results in two identical daughter cells, each containing the same genetic information as the parent cell.

Vocabulary: Mitosis - The process of nuclear division resulting in two nuclei with the same number and kind of chromosomes as the parent nucleus.

Plant Specialized Cells and Their Adaptations

Plants have evolved various specialised cells in plants to perform essential functions. Photosynthetic cells, found in leaves and stems, contain chloroplasts with chlorophyll for light absorption and food production. Their strategic positioning maximizes light exposure for efficient photosynthesis.

Root hair cells demonstrate specialized adaptations for water and mineral absorption. Their extended structure increases surface area for uptake, while large permanent vacuoles facilitate water movement through osmosis. Xylem cells, modified with lignin deposits, form hollow tubes for efficient water and mineral transport throughout the plant.

Vocabulary: Lignin - A complex organic polymer that provides structural support and creates water-impermeable walls in specialized plant cells.

Understanding Coronary Heart Disease and Treatment Methods

Coronary Heart Disease (CHD) is a serious cardiovascular condition that affects millions worldwide. The condition develops when the specialised cells in coronary arteries become compromised due to fatty deposit buildup. These arteries play a crucial role in delivering oxygen-rich blood to the heart muscle, and their blockage can lead to severe complications.

When fatty materials accumulate along the arterial walls, they create plaque that gradually narrows the blood vessels. This narrowing restricts blood flow to the heart muscle, leading to oxygen deprivation of cardiac tissue. Without proper oxygen supply, the heart muscle can become damaged, potentially resulting in a heart attack. Understanding these mechanisms is essential for biology paper 1 topics covering cardiovascular health.

Modern medical science has developed several interventional treatments for CHD, with stent placement being one of the most effective solutions. Stents are small, tube-shaped devices inserted into blocked arteries to maintain proper blood flow. During the procedure, these specialized medical devices push against the arterial walls, compressing the fatty deposits and creating a wider channel for blood flow. This intervention has revolutionized CHD treatment, offering a less invasive alternative to traditional bypass surgery.

Definition: Coronary Heart Disease occurs when the arteries supplying blood to the heart muscle become narrowed or blocked by fatty deposits, potentially leading to heart attacks and other cardiovascular complications.

Highlight: Stent placement is a modern medical intervention that helps maintain blood flow through blocked arteries by creating a wider channel and compressing fatty deposits against the arterial walls.