2.6.2- Mitosis Flashcards
What is cytokinesis?
The type of division of the cytoplasm of a cell following mitosis.
explain what mitosis is.
The type of nuclear division that maintains the same chromosome number and each new daughter cell contains the same genetic information as the parent cell- they are all genetically identical to each other.
What are three general reasons as to why all living organisms produce emetic ally identical daughter cells by mitosis?
Asexual reproduction
Growth
Tissue repair
Lost the four stages of mitosis in order.
Prophase, metaphase, anaphase and telophase.
Give an example of an animal and a plant that reproduces asexually by mitosis.
Single called protoctists (eg Amoeba and Paramecium) divide by mitosis and some plants like strawberries reproduce by mitosis by forming new platelets on the end of stolons.
Explain how organisms use mitosis to grow.
All organisms grow by providing more genetically identical cells by mitosis.
Explain how mitosis is used for tissue repair.
It heals wounds when growth factors are secreted by platelets and macrophages and damaged cells of the blood vessel walls stimulate the proliferation of endothelial and smooth muscle cells to repair damaged blood vessels.
Explain the events that take place in prophase.
Nuclear envelope breaks down, cytoskeleton threads form a spindle, chromatin shortens and thickens as the DNA supercoils and the centriole (in animal cells) divided and they move to opposite poles of the cell.
Explain the events that take place in metaphase.
The pairs of chromatids attach to the spindle threads at the equator region by their centromeres.
Explain the events that take place in the cell at anaphase.
The centromere of each pair of chromatic splits and motor proteins walk along the Tubulidentata threads to pull each sister chromatic in opposite directions, towards opposite poles. Their centromere goes first, causing me the chromosomes to take a V shape.
Explain the events that take place in telophase.
Separated chromosomes reach the poles, new nuclear envelope forms around these and the cell contains two genetically identical nuclei.
Explain that happens in cytokinesis for animal cells.
The plasma membrane folds inwards and ‘nips in’ the cytoplasm.
Explain what happens in plant cells during cytokinesis.
An end plate forms where the spindle equator was and new plasma membrane and cellulose cell wall material are laid down either side of the end plate.
What are chromatids?
Replicates of chromosomes.
