Chromosomes and the cell cycle 2

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Put these diagrams in order!

June 2009

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

Title: Clones

Objectives: Today we are learning:

• What is a stem cell• What are a homologous pair of chromosomes• Outline the process of cell division by budding • Cells produced by meiosis are not genetically

identical

Some single cell organisms (such as amoeba) reproduce by mitosis and cytokinesis

1) Comment on genetic variability in these species (2)• Genetic variability is low • Mitosis produces genetically identical daughter cells• These organisms are clones

2) Do bacterial cells reproduce by mitosis? (1)• No• They reproduce by binary fission• These organisms are clones

Clones: genetically identical organisms derived form one parent

Bacterial DNA is different form Eukaryotic!!

• Not found in the nucleus, found in the cytoplasm • Have a single strand of DNA (single

chromosome)

• DNA is not associated with histones

• Also may have small circles of DNA in the cytoplasm (plasmids)

Stem cells: Cells capable of becoming any type of tissue, types.

A. Omnipotent: can become any tissue

B. Totipotent: can become a range of tissues

Why does the nucleus of the donor egg have to be removed

Why are do scientist have to collect nuclei from adult body cells to implant into the donor egg rather than just using gametes?

Cloned animals

The only cells in a plant that can undergo mitosis are meristem cells.

Some plants can reproduce asexually. A cutting can be taken and given the right treatment this will grow into a new plant.

What does this tell us about the types of cell present within these plants?

Why might this be useful to farmers?

What are the potential disadvantages?

Cloned plants (vegetative propagation)

Sexual reproducetion

MeisoisPlants