(1) Division and differentiation in human cells (F) Cancer Cells (A) Somatic cells Human Cells (E) Uses of stem cells (B) Differentiation in cells (D) Germline cells (C) Stem cells

Division and differentiation in human cells (a) State the 4 main tissue types State how organs are formed Describe each of the 4 main tissue types State what somatic cells are State how somatic cells divide Describe the type of cells which result after somatic cells divide

Re-cap Types of Body Cells You have over 200 DIFFERENT types of body cells. Each of these are called ‘specialised’ since they each have a specialised structure that enables them to do a specific job. TASK: match up the structure and function cards correctly.

Specialised Cells of Animal Tissues Re-cap Specialised Cells of Animal Tissues (somatic cells)

Specialised Cells of Animal Tissues Re-cap Specialised Cells of Animal Tissues (somatic cells) Red blood cells Ciliated epithelial cells Neurone Phagocyte Muscle

Specialised Cells of Animal Tissues Re-cap Specialised Cells of Animal Tissues (somatic cells) B Lymphocyte Smooth muscle Hyaline cartilage

Specialised Cells of Animal Tissues Re-cap Specialised Cells of Animal Tissues (somatic cells) neutrophil Ciliated epithelial cell Red blood cell platelets

Specialised Cells of Animal Tissues Re-cap Specialised Cells of Animal Tissues (somatic cells) Cardiac muscle Squamous epithelial cells Nerve cells T lymphocyte

These are ALL differentiated cells.. AKA… Re-cap Type of cell Function Structural feature Red blood cell Transport of oxygen No nucleus and biconcave to increase the surface area for transport Neurone Communication Very long and has many connections Phagocyte cell Engulf and digest bacteria Have many lysosomes that contain digestive enzymes Muscle cell contraction Contain many mitochondria to provide energy for contraction Ciliated epithelial cells Sweep mucus away from respiratory tract Contains cilia hair which rhythmically beat mucus These are ALL differentiated cells.. AKA…

Somatic cells somatic cells video A somatic cell is a differentiated cell, that forms to make body tissue. Epithelial cells skin cells and cells which line the body’s cavities, e.g the oesophagus and alveoli in the lungs. Connective tissue blood cells, bone cells, cartilage cells Muscle cells muscle tissue including heart muscle, peristaltic muscles in the gut and skeletal muscles Nerve cells spinal cord, brain and nerves.

How is the body organised? Each specific cell is grouped with other cells similar in structure and function to form tissues and ultimately organs. All of our organs are formed from a combination of these somatic tissues. Cells are the basic units of life. Groups of cells work together to form tissues. Groups of tissues work together to form organs. cell tissue organ

How do so many somatic cells arise in the body? Somatic cells divide by mitosis to form more somatic cells. Mitosis is a form of cell division that only occurs in body cells such as somatic cells! So sex cells will NOT undergo cell division! They will undergo a different form of cell division as they are not body cells. mitosis recap video somatic cell division video

The Stages of Cell Division The cytoplasm divides to form 2 new daughter cells Chromosomes line up at the equator. Spindle fibres are fully formed Chromosomes shorten, thicken up and become visible as the nuclear membrane disappears The nuclear membrane re-forms around each group of chromosomes Spindle fibres pull 1 chromatid from each pair to the ‘north’ pole and the ‘south’ pole Chromosomes in the nucleus are uncoiled and are not visible 6 – 3 – 2 – 5 – 4 - 1

The Stages of Cell Division B C D What is the correct order of cell division? B – A – D - C

Somatic cells Somatic cells divide by mitosis to form more somatic cells. The two new cells are called daughter cells and will have the exact same genetic information that the mother cell had. If a parent cell had 46 chromosomes (23 pairs), it will double its genetic material before dividing. This means that both daughter will each have 46 chromosomes (23 pairs). No genetic information is lost, since all the cells are identical. A cell with 2n is said to be diploid. (it has 2 sets of chromosomes) 2n 2n