Flash Player 9 (or above) is needed to view presentations.
We have detected that you do not have it on your computer. To install it, go here.

Like this presentation? Why not share!

Lesson chromsomes and the cell cycle



Powerpoint to accompany cell cycle and mitosis lecture - AS Biology

Powerpoint to accompany cell cycle and mitosis lecture - AS Biology



Total Views
Views on SlideShare
Embed Views



0 Embeds 0

No embeds



Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
Post Comment
Edit your comment
  • 9-905
  • The humangenome is the genome of Homo sapiens, which is stored on 23 chromosome pairs. Twenty-two of these are autosomal chromosome pairs, while the remaining pair is sex-determining. The haploid human genome occupies a total of just over 3 billion DNAbase pairs. The Human Genome Project (HGP) produced a reference sequence of the euchromatic human genome, which is used worldwide in biomedical sciences.The haploid human genome contains ca. 23,000 protein-coding genes, far fewer than had been expected before its sequencing.[1][2] In fact, only about 1.5% of the genome codes for proteins, while the rest consists of non-coding RNA genes, regulatory sequences, introns, and (controversially named) "junk" DNA.[3

Lesson   chromsomes and the cell cycle Lesson chromsomes and the cell cycle Presentation Transcript

  • Title: Cell cycle (again)
    Objectives: Today we are learning to answer the following questions:
    What are the various stages of the cell cycle
    Explain the meaning of the term homologous pair of chromosomes
    What is meant by sisterchromatids
    Describe with the aid of diagrams the main stages of mitosis.
  • What is DNA ?
    What is the point of genetic material?
    What is a gene?
    DNA (Deoxyribonucleic acid)
    Provides a code that codes for proteins, controls activity of the cell
    A sequence of DNA that codes for one protein
    • DNA is held on chromosomes
    • Made of DNA & histone proteins = Chromatin
    • Humans have 46 chromosomes arranged in 23 homologous pairs
    • Homologous pair – 2 chromosomes that contain the same genes; humans = 1 maternal, 1 paternal
    • The number of chromosomes varies between species
  • Sister Chromatids= 2 identical chromatids connected by a centromere.
    Homologous chromosomes
    replicate during interphase
    Original and replicated strand joined at the centromere
  • Put the stages of mitosis in order
    Then answer the questions:
    When a cell divides by mitosis how many cells are made?
    Comment on the similarities and differences of daughter cells to each other and the parent cell.
    Species such as yeast reproduce by cell division, Describe the genetic make up of yeast colonies.
  • The process of creating 2 genetically identical daughter cells from 1 parent cell = MITOSIS
    Division of somatic (body) cells is by mitosis – remember
    • Mitosis make two cells
    • Mitosis makes toes
  • What is happening at each stage of the cell cycle?
    How many chromosomes are in the nucleus during each stage?
  • June 2009
  • Why do cells need to divide?
    What are the processes by which cells divide?
    Growth (mitosis)
    Repair damage (mitosis)
    Replace worn out cells (mitosis)
    Gamete creation (meiosis)
  • Chromosomes visible with light microscope
    Chromosomes are not visible with light microscope
    Chromosomes visible with light microscope
    Chromosomes visible with light microscope
    Chromosomes visible with light microscope