Topic 2: Cells, microscopes, mitosis, immunity

• What is the defining characteristic of eukaryotes?

  Cells with a nucleus
• Prokaryotes lack a nucleus and any other membrane-bound organelles
• Eukaryotic cells may contain organelles such as the nucleus, mitochondria, and Golgi apparatus.
• What is the function of the nucleus in a eukaryotic cell?

  Contains DNA
• The DNA in the nucleus is associated with histone proteins and referred to as chromatin
• The nucleolus is a region within the nucleus where ribosomes are made.
• What is the role of the rough endoplasmic reticulum (RER)?

  Protein synthesis
• The RER is coated with ribosomes
• What does the smooth endoplasmic reticulum (SER) synthesize?

  Lipids
• The Golgi apparatus modifies proteins and lipids received from the RER and SER.
• What is the function of ribosomes in protein synthesis?

  Translate RNA into protein
• Mitochondria are the site of ATP production during aerobic respiration
• The cristae in mitochondria provide a large surface area for respiration.
• What is the role of lysosomes in the cell?

  Digest old organelles
• Match the organelle with its function:

  Chloroplasts ↔️ Site of photosynthesis

  Plasma membrane ↔️ Controls substance movement

  Centrioles ↔️ Form spindle fibres
• The cell wall in plants is made of cellulose
• Flagella are made of bundles of microtubules that contract to propel the cell forward.
• Where are cilia found in the human body?

  Trachea
• What is the smallest functioning part of an organism?

  The cell
• Arrange the levels of organization in increasing complexity:

  1️⃣ Cell

  2️⃣ Tissue

  3️⃣ Organ

  4️⃣ Organ system
• The lungs are an example of an organ made up of different types of tissues.
• What organelles do prokaryotes and eukaryotes share in common?

  Cytoplasm, cell membrane, ribosomes
• Prokaryotic DNA is a single circular chromosome
• What is the size of prokaryotic ribosomes?

  70S
• Prokaryotic cells are much smaller than eukaryotic cells.
• Bacteria replicate by binary fission
• Arrange the steps of bacterial replication by binary fission:

  1️⃣ DNA replicates once

  2️⃣ Plasmids replicate

  3️⃣ Cell grows bigger

  4️⃣ Cytoplasm divides

  5️⃣ New cell wall forms

  6️⃣ Cytokinesis occurs

  7️⃣ Two new cells are formed
• Why are viruses technically not considered alive?

  Cannot reproduce alone
• Viruses contain nucleic acid (DNA or RNA) and enzymes surrounded by a protein coat called a capsid.
• Viruses, unlike cells, do not contain cytoplasm, a cell membrane, or ribosomes
• How do viruses enter host cells?

  Bind to receptors
• Arrange the steps of viral replication:

  1️⃣ Virus binds to host cell

  2️⃣ Viral capsid releases nucleic acid

  3️⃣ Viral DNA integrates into host genome

  4️⃣ Viral proteins are translated

  5️⃣ New viral particles are assembled
• What is the name of the folded structures within the inner membrane of a mitochondrion?

  Cristae

  
• What is the name of the structure that connects two plant cells together?

  Middle lamella

  
• What is the correct order of biological organization from smallest to largest?

  Cell → Tissue → Organ → Organ System

  
• What type of proteins are located on the surface of the HIV envelope?

  Attachment proteins

  
• The HIV envelope surrounds the capsid

  
• What is the structure in a chloroplast labeled as "grana"?

  Stacks of thylakoids

  
• The fluid-filled space in a chloroplast is called the stroma

  
• What is the bacterial cell wall made of?

  Murein