Types of Reproduction
Gametes are sex cells.
Fertilisation is when half the genetic material comes from male gamete and half come from female gamete and they fuse together to form a zygote.
Zygote is a fertilized egg.
Embryo is a divided zygote.
Binary Fission in Bacteria
Bacteria are microscopic organisms made up of one cell and they do not have a nucleus but a loop of DNA. When bacteria, reproduce asexually the DNA loop is copied so that there is some for each new cell. The bacterial cell deivides into two by making a new cell wall. This type of asexual reproduction is called binary fission.
Spore Production in Fungi
Pin mould is a fungus which grows on bread and reproduces asexually by making spores. They are small and light like spects of dust, and float through the air. When spore lands on a damp surface, it splits open and thread grows out. The hypha (thread) grows over surface of bread forming a dense network of threads called a mycelium. Eventually, short hyphae grow upwards and produce spore casesor sporangia at their tips. Inside each sporangium hundreds of new spores are formed asexually by division of nuclei. Each nucleus gains a small qty of cytoplasm and a protective spore case.
When ready, it breaks open and spores are dispersed.
Tuber formation in potatoes * Potatoes reproduce asexually by stem tubers. * They are swollen underground stems that grow from parent plant * Sucrose is transported in the phloem from the leaves into these underground stems that swell as they convert sucrose > starch. * Parent plant dies at end of growing season but tubers are left to survive over the winter. * Farmers dig em up and sell em. * Some are kept as seed potatoes to plant the next year and all the tubers are genetically identical. * When regrowing, new shoots/roots emerge from growing point of potato, know as eyes.
| Asexual | Sexual | Advantages | * Fast * Reproduces rapidly to spread and colonise areas where the parent
Fertilisation is when half the genetic material comes from male gamete and half come from female gamete and they fuse together to form a zygote.
Zygote is a fertilized egg.
Embryo is a divided zygote.
Binary Fission in Bacteria
Bacteria are microscopic organisms made up of one cell and they do not have a nucleus but a loop of DNA. When bacteria, reproduce asexually the DNA loop is copied so that there is some for each new cell. The bacterial cell deivides into two by making a new cell wall. This type of asexual reproduction is called binary fission.
Spore Production in Fungi
Pin mould is a fungus which grows on bread and reproduces asexually by making spores. They are small and light like spects of dust, and float through the air. When spore lands on a damp surface, it splits open and thread grows out. The hypha (thread) grows over surface of bread forming a dense network of threads called a mycelium. Eventually, short hyphae grow upwards and produce spore casesor sporangia at their tips. Inside each sporangium hundreds of new spores are formed asexually by division of nuclei. Each nucleus gains a small qty of cytoplasm and a protective spore case.
When ready, it breaks open and spores are dispersed.
Tuber formation in potatoes * Potatoes reproduce asexually by stem tubers. * They are swollen underground stems that grow from parent plant * Sucrose is transported in the phloem from the leaves into these underground stems that swell as they convert sucrose > starch. * Parent plant dies at end of growing season but tubers are left to survive over the winter. * Farmers dig em up and sell em. * Some are kept as seed potatoes to plant the next year and all the tubers are genetically identical. * When regrowing, new shoots/roots emerge from growing point of potato, know as eyes.
| Asexual | Sexual | Advantages | * Fast * Reproduces rapidly to spread and colonise areas where the parent