Stem Cells A stem cell is a cell that can divide (by mitosis) an unlimited number of times Each new cell (produced when a stem cell divides) has the potential to remain a stem cell or to develop in...
Meiosis: Source of Genetic Variation Meiosis gives rise to cells that are genetically different from each other and is the type of cell division used to produce gametes (sex cells) During meiosis, ...
Locations of Genes on a Chromosome Every chromosome consists of a long DNA molecule that contains several hundred or even thousands of different genes coding for different proteins A length of DNA ...
Fertilisation in Mammals During sexual intercourse, semen is ejaculated high up into the vagina of the female, near the cervix The sperm cells then follow a chemical trail released by the egg cell ...
Mammalian Gametes Gametes Gametes are the sex cells of an organism For example, the sperm and egg (ovum) cells in humans Gametes fuse during fertilisation to form a zygote Fertilisation is the fusi...
Pracitical: Identifying Mitosis in Plant Cells Growth in plants occurs in specific regions called meristems The root tip meristem can be used to study mitosis The root tip meristem can be found jus...
The Stages of Mitosis Mitosis is the process of nuclear division by which two genetically identical daughter nuclei are produced that are also genetically identical to the parent cell nucleus (they...
The Cell Cycle Mitosis is part of a precisely controlled process known as the cell cycle The cell cycle is the regulated sequence of events that occurs between one cell division and the next The ce...
Recognising Organelles from Electron Microscope Images Electron microscopes can produce highly detailed images of animal and plant cells This is because they have a higher resolution, or resolving ...
