Unit 2

• Who is the presenter of the biology video?

  Miss Estrich
• How long has Miss Estrich been teaching?

  14 years
• What is the purpose of the video?

  To cover topic 2 of A-level biology
• 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 focus of Miss Estrich's workbook?

  A-level biology topics one to four
• 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 is the overall function of the nucleus?

  DNA replication and transcription
• What structures are found within the nucleus?

  Nuclear envelope, pores, nucleoplasm, chromosomes, nucleolus
• What is the role of the nucleolus?

  RNA production and ribosome assembly
• What distinguishes rough endoplasmic reticulum from smooth endoplasmic reticulum?

  Rough ER has ribosomes on its surface
• What occurs in the rough endoplasmic reticulum?

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

  Synthesis of lipids and carbohydrates
• What is the structure of the Golgi apparatus?

  Folded membrane system
• What happens in the Golgi apparatus?

  Modification and packaging of proteins
• What are lysosomes involved in?

  Digestion and phagocytosis
• What is the function of mitochondria?

  Site of aerobic respiration
• What is unique about mitochondrial DNA?

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

  rRNA and proteins
• What sizes of ribosomes are found in eukaryotic and prokaryotic cells?

  80s in eukaryotes, 70s in prokaryotes
• What is the function of the vacuole in plant cells?

  Provides support and stores substances
• What is the role of chloroplasts?

  Site of photosynthesis
• What are the components of chloroplasts?

  Double membrane and thylakoid membranes
• What is the function of the cell wall?

  Provides structural strength and support
• What is the composition of plant cell walls?

  Cellulose
• What is the function of the plasma membrane?

  Controls entry and exit of substances
• What are the key differences between prokaryotic and eukaryotic cells?

  Prokaryotes are smaller and lack organelles
• What is the structure of viruses?

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

  Inside host cells by injecting nucleic acid
• What are the three main types of microscopes?

  Optical, transmission electron, scanning electron
• What is 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 than light
• What is the difference between transmission and scanning electron microscopes?

  TEM produces 2D images, SEM produces 3D images
• 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 homogenization in cell fractionation?

  Breaking open cells to release contents
• What is ultra centrifugation?

  Separating organelles by spinning at different speeds
• What is the order of organelle density during centrifugation?

  Nuclei, chloroplasts, mitochondria, lysosomes, ER, ribosomes
• What are the stages of the eukaryotic cell cycle?

  Interphase, mitosis, cytokinesis