GENBIO

• cell cycle


  it consists of sequential phases of events wherein the parent cell divides and replicates DNA materials to produce two daughter cells.
• duplication, division


  fill in the blanks.

  cells follow definite stages of growth, ____________________ and ______________________.
• cell division


  it is also known ascell reproduction, it allows organisms to reproduce asexually, grow, and repair worn-out or damaged tissues.
• cell replacement


  it occurs when old cells in the body die and new cells form.
• sexual reproduction


  it involves two specialized cells, called gametes, coming from the parents that will result to a unique offspring.
• asexual reproduction


  it is the production of offspring from a single parent without the involvement of gametes.
• binary fission


  this is when the cell pinches apart, splits into two, then a new cell wall forms between two daughter cells.
• interphase


  it is the growth period in the cell cycle and is divided into three parts.
• Gap 1 (


  G₁)- the cell carries out its normal metabolic functions.

  - cells increase their size, as their organelles increase in number.

  - embryonic cells divide rapidly and exponentially.

  - cells spend most of their life cycle in this phase.
• Synthesis (


  S)- the time that the cell makes a copy of the genetic material in the form of nuclear DNA.

  - makes copies of chromosomes.

  - ensures that the daughter cell receives exact copies of the parent's genetic material.

  - cells duplicate only at this stage.

  - cells produce a copy of microtubules that will later help the cell organize its contents.
• Gap 2 (


  G₂)- cells continue to carry out their normal functions and also undergo further growth.

  - contains a critical checkpoint to make sure that everything is duplicated and in order.
• Mitosis (


  M)- involves the division of the nucleus and the genetic material.

  - divided into four parts (prophase, metaphase, anaphase, telophase).

  - the hereditary material of the parent cell is given to the daughter cells.

  - distributes an identical set of genetic instructions, that is, one copy of each chromosome to the two daughter cells.

  - prepares the cell for cytokinesis.
• prophase


  - start of mitosis.

  - chromatin condenses into tightly coiled chromosomes.

  - chromosomes are packaged into neat bundles.

  - nuclear envelope breaks down.

  - nucleolus disappears.

  - lines up chromosomes at the center of the cell.
• metaphase


  - chromosomes appear to line up along a plane equidistant.

  - happens fast, moves chromosomes toward the middle of the cell.
• anaphase


  - sister chromatids are tightly paired due to the centromere and protein cohesin.

  - cohesin breaks down and the sister chromatids separate from each other.

  - where the cleavage furrow appears.
• telophase


  - two complete sets of identical chromosomes are now positioned at each pole of the cell.

  - reverse of the major events in prophase happen.

  - chromosomes are no longer visible.

  - cell plates form.
• cytokinesis


  it divides the cytoplasm of the cell and involves splitting the cytoplasm into two cells and completes the entire stage of the cell cycle, it begins early during telophase and continues after the nuclei have formed in the daughter cells, it makes the cell have a very narrow middle, and appears to be like the number 8.
• chromosome


  it is a long, continuous thread of DNA wound together by DNA-associated proteins.
• 46


  fill in the blank.

  each of your body cells consists of ______ chromosomes.
• chromatin


  it is responsible for packaging the DNA efficiently into smaller volume so that it fits the nucleus of a cell to protect the DNA structure and sequence.
• chromatid

  it refers to each strand of the duplicated chromosomes.
• sister chromatids


  this refers to a pair of chromatids.
• centromere


  it is a region of condensed pinched chromosomes that holds that sister chromatids together.
• kinetochore


  it is located at the centromere and is attached to the long spindle fibers during cell division.
• telomeres


  it is a structure located at the end of the DNA molecule that contains repeated nucleotides, which contain genetic information that do not translate into traits.
• 10 feet


  fill in the blank.

  if a chromosome was stretched end to end, it will be about ___ feet long.
• true


  true or false.

  prokaryotic cells have similar structures with eukaryotic cells but not identical.
• membrane-bound organelles, cytoskeleton


  fill in the blanks.

  prokaryotic cells lack _______________________ and _____________________.
• nutrients are short in supply, no instructions to divide

  fill in the blanks.

  cells do not divide in situations where _________________________ and there are ____________________________.
• external factors


  these come from outside the cell and are in the form of messages from nearby cells or from remote parts of the organism's body.
• physical, chemical external


  fill in the blanks.

  ____________________ and _______________________ factors help regulate the cell cycle.
• contact inhibition


  this is a phenomenon that occurs when a cell touched another cell and it stops dividing.
• anchorage dependent


  this is a phenomenon that occurs when cells only grow if the surface is available and stop dividing when detached from the culture dish.
• chemical signals


  fill in the blank.

  ________________________ released by the cell such as growth factors provide instructions for other cells to grow.
• growth factors

  these are proteins that stimulate cell division, which have the ability to activate specific genes to trigger cell growth.
• Deoxyribonucleic acid


  this is the full meaning of DNA.
• internal factors


  these come from inside the cell that include several types of molecules in its cytoplasm.
• kinase


  it is an enzyme that transfers a phosphate group from one molecule to the target molecule, it accelerates the energy of the target molecule or changes its shape.
• cyclins

  these are rapidly destroyed at certain points in the cell cycle to allow cells to progress fromG₁to M stage.
• cyclins, cyclin-dependent kinases


  fill in the blanks.

  the progress of a cell from one phase to the next of the cell cycle is controlled by the interaction of special proteins called __________________ and ________________________.