T3: Voice of the Genome

• What are the basic structural units of all living organisms?

  Cells
• How are cells organized in multicellular organisms?

  Cells are organized into tissues, tissues into organs, and organs into organ systems.
• What type of cells are humans made up of?

  Eukaryotic cells
• What is the function of the nucleus in eukaryotic cells?

  The nucleus contains DNA and is involved in regulating gene expression and cell division.
• What surrounds the nucleus of a eukaryotic cell?

  A double membrane called the envelope
• What is chromatin composed of?

  DNA wrapped around histone proteins
• What is the function of the nucleolus?

  It is the site of ribosome production.
• What is the role of the Rough Endoplasmic Reticulum (RER)?

  The RER folds and processes proteins made on the ribosomes.
• What distinguishes the Smooth Endoplasmic Reticulum (SER) from the RER?

  The SER produces and processes lipids, while the RER is involved in protein synthesis.
• What is the function of the Golgi Apparatus?

  It modifies and packages proteins and lipids for transport.
• What are mitochondria primarily responsible for?

  Cellular respiration
• What is the structure of mitochondria?

  Mitochondria are usually oval-shaped and bound by a double membrane.
• What are centrioles involved in?

  Cell division
• What is the composition of 80S ribosomes?

  They are composed of two subunits and are the site of protein synthesis.
• What do lysosomes contain?

  Digestive enzymes
• Where are proteins produced in the cell?

  On the ribosomes.
• What happens to proteins produced on the ribosomes on the RER?

  They are folded and processed in the RER.
• How are proteins transported from the RER to the Golgi apparatus?

  In vesicles.
• What modifications occur to proteins in the Golgi Apparatus?

  Proteins are modified, such as carbohydrates being added to form glycoproteins.
• What is the process by which some proteins leave the cell?

  Exocytosis.
• What is the cell wall of prokaryotic cells made of?

  Peptidoglycan.
• What is the function of the slime capsule in prokaryotic cells?

  It helps the cell retain moisture and adhere to surfaces.
• What are plasmids?

  Circular pieces of DNA in prokaryotic cells.
• What is the role of the flagellum in prokaryotic cells?

  It rotates to move the cell.
• What are pili in prokaryotic cells?

  Hair-like structures that attach to other bacterial cells.
• What is the function of mesosomes in prokaryotic cells?

  Their function is debated, but they may contain enzymes required for respiration.
• What is the zona pellucida?

  A protective coating around the ovum.
• What is the main purpose of the zona pellucida during fertilization?

  To prevent polyspermy.
• What type of nucleus does an ovum contain?

  A haploid nucleus.
• What do cortical granules do during fertilization?

  They release substances that cause the zona pellucida to harden.
• What surrounds the egg cell for protection?

  Follicle cells.
• Why do sperm cells contain many mitochondria?

  To provide energy for the rotation of the flagellum.
• What is the function of acrosomes in sperm cells?

  They contain digestive enzymes that break down the zona pellucida.
• What are the steps of fertilization?

  1. The sperm head meets the zona pellucida, and the acrosome reaction occurs.
  2. The sperm head fuses with the egg cell membrane, allowing the sperm nucleus to enter.
  3. The cortical reaction occurs, hardening the zona pellucida to prevent polyspermy.
  4. The nuclei fuse, restoring a full set of chromosomes and forming a diploid zygote.

  
• What is the locus of a gene?

  Its location on a chromosome.
• What does it mean for alleles to be autosomally linked?

  They are inherited together because they are on the same chromosome.
• Why are some genes considered sex-linked?

  They occur on the X chromosome.
• Why are sex-linked genetic disorders more common in men?

  Men have only one X chromosome, so they need only one copy of the allele for expression.
• What is an example of a sex-linked genetic disorder?


  Haemophilia.
• What is the cell cycle?

  A process in which cells divide to produce two genetically identical daughter cells.