BIO 118 Lec 11 cell cycle S (1).pptx

BIO 118 Lec 11 cell cycle S (1).pptx - The Cell Cycle...

Info icon This preview shows pages 1–12. Sign up to view the full content.

The Cell Cycle Chapter 12
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Image of page 2
How do new cells arise? The cell theory – all cells from preexisting cells…but how do those cells arise? Meiosis- Cell division that leads to the production of sperm and eggs. Mitosis- Cell division that leads to the production of all other kinds of cells- somatic cells. Both are usually accompanied by cytokinesis- the division of the cytoplasm into two distinct cells.
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

How do new cells arise? Mitosis and meiosis are fundamentally different. Mitosis-the genetic material is copied and then divided equally between two cells. This is cellular replication- no genetic replication Meiosis-the genetic material is copied and split between the two cells. Thus, the daughter cells are genetically different from each other and have half the amount of genetic material as the parent cell.
Image of page 4
How do cells replicate? 1. Copy genetic material 2. Separate the copies 3. Divide the cytoplasm to create two complete cells
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

What is the genetic material in a cell? The genetic material is the DNA. During cell division, DNA is coiled around proteins called histones and into chromosomes. The DNA-histone complex is called chromatin A gene is a region of DNA that codes for a protein. First, the DNA is copied. The copied chromosome is called a chromatid
Image of page 6
What are the general phases of mitosis? M phase- cells are in the process of separating their chromosomes Interphase-the rest of the time. Chromosomes are uncoiled. The cell is either growing and preparing to divide or fulfilling its specialized function in an individual. S phase- the process of copying the genetic material. But what is the order of the cell cycle and does it cycle continuously without any pauses?
Image of page 7

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

What are the general phases of mitosis? Where is S phase positioned in interphase? Alma Howard and Stephen Pelc investigated the possibilities: 1. The S phase is immediately before M phase with a single gap between the end of M phase and the start of S phase. 2. The S phase is immediately after M phase, with a single gap between the end of S phase and the start of M phase. 3.  There is a gap before S phase and a gap after S phase.
Image of page 8
How are questions about the cell cycle answered? Differentiating these possibilities was done using experiments with asynchronous cells…the cells were randomly selected at different stages in the cell cycle Thus, at any given time an asynchronous culture would have at least one cell at each stage in the cycle and the cells would move through the cycles at the same rate and in the same order.
Image of page 9

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

How are questions about the cell cycle answered? Pulse Chase experiments
Image of page 10
What are the general phases of mitosis Where is S phase positioned in interphase?
Image of page 11

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Image of page 12
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern