GCSE Biology Paper 1 (Part 1) 2024 Questions and Answers REVISION

Recent questions

• What is cell biology?

  Cell biology is a branch of biology that focuses on the structure, function, and behavior of cells, which are the basic units of life. It encompasses various aspects such as the organization of cells, their interactions, and the processes that occur within them. Understanding cell biology is crucial for comprehending how organisms grow, develop, and respond to their environment. This field also explores the differences between various cell types, such as prokaryotic cells, which lack a nucleus, and eukaryotic cells, which have a defined nucleus and organelles. By studying cell biology, scientists can gain insights into health, disease, and the underlying mechanisms of life.

• How do you calculate magnification?

  Magnification is calculated using a simple formula that relates the size of the image to the size of the real object. The formula is: magnification = size of image / size of real object. For example, if an image measures 40 mm and the actual object measures 0.1 mm, the magnification would be 400 times. This means that the image appears 400 times larger than the actual object. Understanding magnification is essential in fields such as microscopy, where it allows scientists to observe and analyze small structures that are not visible to the naked eye, enhancing our understanding of biological processes.

• What is the difference between mitosis and meiosis?

  Mitosis and meiosis are two distinct processes of cell division that serve different purposes in living organisms. Mitosis results in the production of two identical diploid cells, each containing the same number of chromosomes as the original cell, which is typically 46 in humans. This process is essential for growth, repair, and asexual reproduction. In contrast, meiosis produces four genetically different haploid cells, each with half the number of chromosomes (23 in humans). This process involves two rounds of cell division and is crucial for sexual reproduction, as it generates gametes (sperm and eggs) that combine during fertilization to form a new organism. Understanding these processes is fundamental in genetics and developmental biology.

• What are the functions of chloroplasts?

  Chloroplasts are specialized organelles found in plant cells that play a vital role in photosynthesis, the process by which plants convert light energy into chemical energy. They contain chlorophyll, the green pigment that captures sunlight, allowing plants to transform carbon dioxide and water into glucose and oxygen. This process not only provides energy for the plant but also contributes to the oxygen supply in the atmosphere, making chloroplasts essential for life on Earth. Additionally, chloroplasts are involved in other metabolic processes, such as the synthesis of fatty acids and amino acids, highlighting their importance in plant biology and ecology.

• What adaptations help the small intestine absorb nutrients?

  The small intestine has several adaptations that enhance its ability to absorb nutrients efficiently. One key adaptation is the presence of villi, which are tiny, finger-like projections that increase the surface area available for absorption. This allows for more nutrients to be taken up into the bloodstream. The walls of the small intestine are also thin, facilitating the diffusion of nutrients. Furthermore, the long structure of the small intestine provides ample time for digestion and absorption to occur. A rich blood supply ensures that absorbed nutrients are quickly transported to the rest of the body, while numerous mitochondria provide the energy needed for active transport processes. These adaptations collectively optimize nutrient absorption, making the small intestine a critical component of the digestive system.