Cell Cycle and Mitosis Quiz

Cell Cycle

• The cell cycle is the period of time between one cell division and the next
• In unicellular organisms, division results in new individuals
• In multicellular organisms, division replaces old or damaged cells

Mitosis

• The process of nuclear division where the number of chromosomes remains the same
• Part of the cell cycle

Cytokinesis

• The division of the cytoplasm occurs after mitosis

Asexual Reproduction

• Reproduction requiring only one parent
• No special reproductive organs are needed
• Offspring have the same genetic information as the parent

Chromatin

• DNA wound around proteins called histones

Chromosomes

• Condensed chromatin, visible during mitosis
• Rod-like structures

Phases of Mitosis

• There are 5 phases of mitosis:
  • Interphase
  • Prophase
  • Metaphase
  • Anaphase
  • Telophase

Interphase

• Known as the "resting phase"
• Cells grow in size, producing more nucleic acids and proteins
• Cells produce copies of cellular organelles
• Chromosomes replicate but cannot be seen

Prophase

• Double chromosomes become visible
• Each chromosome consists of two sister chromatids connected by a centromere

Metaphase

• Centromeres line up on the equator (metaphase plate) of the cell
• By the end, centromeres divide and separate the daughter chromosomes to opposite sides of the cell

Anaphase

• Daughter chromosomes move to opposite sides of the cell (poles)
• Movement is due to shortening of microtubules

Telophase

• Chromosomes uncoil and return to their thread-like appearance
• Nuclear membranes and nuclei reform
• Cytokinesis begins during late anaphase and finishes during Telophase

Mnemonic Device

• A way to remember the order of the phases of mitosis – I PUNCHED MY AUNT TILLY!

Mitosis in Plants

• Similar to animal mitosis, but plants lack centrioles and spindle fibers take their place
• The cell wall does not pinch inward. A cell plate divides the cell into two

Asexual Reproduction continued

• Protein that causes cells to go through the cell cycle is called cyclin
• Occurs only through the process of mitosis
• All offspring have the same genetic information

Types of Asexual Reproduction

• Budding: Parent divides unequally, new individuals develop from buds (e.g., yeast, hydra)
• Binary Fission: Parent divides equally, resulting in two separate individuals (e.g., paramecium)
• Spore Formation: Single specialized cells germinate when released from the parent (usually covered by a protective coating)
• Regeneration/Fragmentation: Ability to regrow new body parts to new organisms (e.g., hydra, planaria, starfish)
• Vegetative Reproduction/Propagation: Roots, stems, and leaves divide and differentiate to produce the same organism (e.g., strawberry plants, pick-a-back plants)