Cell Cycle And Asexual Reproduction 🌳 Flashcards
Describe prophase.
Prophase is first and in this stage nucleolus and nuclear membrane disappear and spindle fibres form centrioles at opposite ends of the cell.
Describe metaphase.
Chromosomes line up in the centre of the cell, spindle fibres attach to centromeres.
Describe anaphase.
Spindle fibres shorten, centromere pull apart, sister chromatids move to opposite ends of the cell.
Describe telophase.
Spindle fibres disappear and nuclear membrane re-appears, the cell splits and there are two cells.
Examples of asexual reproduction.
Binary fission,
Budding,
Fragmentation,
Spores
Briefly describe binary fission.
In this process a parent cell divides so each new cell contains a single chromosome carrying a complete set of DNA identical to that of the parent cell.
Briefly describe budding.
First a copy of the nucleus is made then a tiny bud starts to form on the cell wall this bud containing the duplicated nucleus continues to grow until it breaks away to become an independent cell
Briefly describe fragmentation.
A small piece or fragment breaks away from the main organism and grow into a new individual.
Briefly describe spores.
A spore is a reproductive cell that can grow into a new individual through mitosis.
What is the cell theory? List the points that make up the cell theory.
- All living organisms are composed of cells.
- Cells are the basic units of a structure and function in all organisms.
- All cells come from previously existing cells.
- The activity of an organism depends on the total activity of its independent.
Types of asexual reproduction in plants.
Plants can reproduce asexually through meristems, layering, grafting and new plants from roots and stems
Describe “meristem”
In the tips of plant roots and stems there are special growing areas called meristems. Meristems are made of unspecialized cells that go through mitosis and cell division repeatedly to produce new cells at a certain point in the plants growth these cells specialize into the cells that make up the roots stems and leaves of the plant.
Describe layering.
Layering is a method of growing roots from the branches or shoots of a parent plant by covering those parts with soil.
Describe grafting.
Stems from one plant can be attached or grafted to the rooted stock of a related or similar plant.
What is a local example of grafting.
McIntosh apples are from grafting.
