Alevel biology

• Who is the presenter of the biology video?

  Miss Estrich
• What is the main topic of the video?

  Complete topic 2 of A-level biology
• How many years has Miss Estrich been teaching?

  14 years
• Why does Miss Estrich create content for YouTube and Instagram?

  To help students prepare for exams
• What is the name of the sponsor mentioned in the video?

  Biosnip
• What type of content does Biosnip provide?

  Diagrams, graphs, and quizzes
• What is the purpose of Miss Estrich's active recall workbook?

  To aid in revision and consolidation
• What are the key organelles in eukaryotic cells?

  • Nucleus
  • Endoplasmic reticulum (smooth and rough)
  • Golgi apparatus
  • Lysosomes
  • Mitochondria
  • Ribosomes
  • Vacuole
  • Chloroplasts
  • Cell wall
  • Plasma membrane
• What are the key structures within the nucleus?

  Nuclear envelope, pores, nucleoplasm, chromosomes, nucleolus
• What is the overall function of the nucleus?

  DNA replication and mRNA synthesis
• What is produced in the nucleolus?

  RNA and ribosomes
• What are the two types of endoplasmic reticulum?

  Smooth and rough endoplasmic reticulum
• What occurs in the rough endoplasmic reticulum?

  Protein synthesis
• What is the function of the smooth endoplasmic reticulum?

  Synthesis and storage of lipids and carbohydrates
• What happens in the Golgi apparatus?


  Modification and packaging of molecules
• What is the structure of the Golgi apparatus?

  Folded membrane with a systemy shape
• What are lysosomes involved in?

  Digestion and phagocytosis
• What is the main function of mitochondria?

  Aerobic respiration and ATP production
• What is unique about mitochondrial DNA?

  It is similar to prokaryotic DNA
• What are ribosomes made of?

  rRNA and proteins
• What size ribosomes are found in eukaryotic cells?

  80S ribosomes
• What is the function of vacuoles in plant cells?

  Support and storage of substances
• What is the function of chloroplasts?

  Site of photosynthesis
• What are the thylakoid membranes in chloroplasts responsible for?

  Light-dependent reactions of photosynthesis
• What provides structural strength to plant cell walls?

  Cellulose
• What is the function of the plasma membrane?

  Controls entry and exit of substances
• What is a key difference between prokaryotic and eukaryotic cells?

  Prokaryotic cells lack membrane-bound organelles
• What is the structure of viruses?

  Genetic material, capsid, and attachment proteins
• How do viruses replicate?

  Inside host cells by injecting nucleic acid
• What are the methods of studying cells?

  1. Microscopy
  2. Cell fractionation
  3. Ultra centrifugation
• What is the definition of magnification?

  How many times larger the image is
• What determines the resolution of optical microscopes?

  The wavelength of light
• Why do electron microscopes have higher resolution?

  Electrons have a shorter wavelength
• What is the difference between optical and electron microscopes?

  Optical uses light; electron uses electrons
• What type of images do optical microscopes produce?

  Color images
• Why can't living samples be observed with electron microscopes?

  Samples must be in a vacuum
• What is the formula for calculating magnification?

  Image size = actual size × magnification
• What conditions are required for cell fractionation?

  Cold, isotonic, and buffered solution
• What is the purpose of homogenization in cell fractionation?

  To break open cells and release organelles
• What happens during ultra centrifugation?

  Organelles separate according to density