Biology exam notes: Units on reproduction in plants and animals (sexual & assexual), mitosis & meiosis, growth and cell division

BIOLOGY TERM 3 Reproduction Asexual reproduction ·leads to the production of offspring that are very like their parents and so carry on adaptations to the conditions they live in. ·Does not depend on the production of specialised reproductive cells (gametes) ·Does not depend on the chance meeting of sperm and egg, eg. Aquatic species shed their gametes into the water. ·Does not depend on two mature individuals, one to produce sperm and the other to produce …

…Chromosomes condense and become visible ·Spindle apparatus begins to form ·Nuclear membrane disappears Metaphase ·the spindle fibres attach to the chromosomes ·the chromosomes line up at the spindle equator Anaphase ·The chromosomes split at the centromere and sister chromatids arc pulled to opposite poles by the spindle fibres ·Chromatids are now independent chromosomes Telophase ·Chromosomes de-condenses and lengthens ·New nuclear membrane forms ·Usually, the cytoplasm also divides at this stage. This is known as CYTOKINESIS