Hkdse Biology Connecting Concepts 1a Answers Jun 2026

~80–120 words per 6‑mark question, ~120–150 words per 8‑mark question.

Below is a comprehensive breakdown of the core concepts, answering strategies, and structural solutions for the chapters covered in Book 1A. Core Topics Covered in Book 1A hkdse biology connecting concepts 1a answers

| Topic | Key Fact | Link to Another Topic | |-------|----------|-----------------------| | | Stacked grana increase surface area. | Enables high‑rate ATP synthesis → fuels Calvin cycle. | | Mitochondrial cristae | Folded inner membrane. | Provides space for electron‑transport chain → oxidative phosphorylation. | | DNA → RNA → Protein | Central Dogma. | Gene mutations affect protein function → phenotype (e.g., sickle‑cell disease). | | Homeostasis (temperature) | Hypothalamus ↔ autonomic nerves ↔ effectors (shivering, vasoconstriction). | Maintains core temperature despite environmental change. | | Enzyme inhibition | Competitive: substrate competes; Non‑competitive: changes Vmax. | Regulation of metabolic pathways (e.g., glycolysis). | | Food webs | Energy loss ~10 % per trophic level. | Explains why apex predators are few and vulnerable to bio‑accumulation. | | Antibiotic resistance | Selective pressure + gene transfer. | Public health impact → need for stewardship programs. | | Hormonal feedback | Negative feedback loops (e.g., thyroid axis). | Keeps physiological variables within narrow limits. | ~80–120 words per 6‑mark question, ~120–150 words per

Protein synthesis involves the nucleus (transcription), rough endoplasmic reticulum (translation), and Golgi apparatus (modification and packaging). 2. Movement of Substances Across Membrane Mechanisms | Enables high‑rate ATP synthesis → fuels Calvin cycle