Tag Archives: asexual

Term 2 – Week 5: Reproduction (Year 11)

asexual_sexual_reproduction

This week in Year 11 Biology we are starting to discuss another body system – the reproductive system. First we will study the concepts of asexual and sexual reproduction and then learn how reproduction occurs in unicellular and multicellular organisms.

Asexual Reproduction – Plants, bacteria and fungi

Draw a diagram to show each of the following types of asexual reproduction:

  • binary fission (eg. bacteria, some algae)
  • budding (eg. yeast, hydra)
  • bulbs (eg. daffodils)
  • runners and rhizomes (eg. strawberries)
  • fragmentation (eg. sea stars, flatworms)
  • spore formation (eg. fungi)
  • parthenogenisis (eg. stick insects, some reptiles)

This YouTube video, Asexual Reproduction, shows budding in Hydra and Anenomes and binary fission in Paramecium, as well as asexual reproduction in Volvox, a green algae.

Sexual Reproduction Handout

Sexual Reproduction

mandarin fish mating

Image Source

Today we finished our unit on Reproduction by looking at the variety of strategies that vertebrates use to produce offspring. From broadcast spawning (in most fish) where eggs and sperm are released into the aquatic environment, to the production of amniotic eggs in birds and the vivaporous births of mammals, there are different degrees of resources put into reproduction. Different species of sharks show a variety of different strategies from external egg development (oviparous) to placental live birth (viviparous) to internal egg development with live birth (ovoviviparous) to interuterine cannibalism. Terrestrial organisms require internal fertilisation to protect the gametes from dessication and allow the embryo to form either protected by a shell or within the uterus or womb.

Try this student activity to compare asexual and sexual reproductive strategies. More about reproduction here. Check out the wiki for more activities and information.

Vegetative Reproduction

Vegetative reproduction

Image Source

This week we are starting the topic “Reproduction” by looking at vegetative or asexual methods of reproduction. Complete the table titled “Types of Vegetative Reproduction” using your text and activity manual. Plants that are produced by vegetative reproduction are genetically identical to their parent plants, which is a very useful trait for horticulturalists. They may use the following methods:

  • Runners (strawberries, water hyacinth)
  • Cuttings (geraniums, roses)
  • Rhizomes (underground stems, as in ferns, irises, ginger and galangal)
  • Tubers (potatoes0
  • Bulbs (daffodils, tulips, onions)
  • Suckers (undersground stems that arise a distance from the parent plant eg. elm trees and blackberries)

Reproduction – Sexual and Asexual

Photo Source

This week we are looking at reproduction – by the end of this unit you will understand the concepts of sexual and asexual reproduction and describe how reproduction occurs in unicellular and multicellular organisms. You will learn that prokaryotes reproduce by binary fission and that eukaryotes can also reproduce asexually by mitosis, budding, parthenogenesis or vegetative reproduction (runners, rhizomes, tubers, bulbs and cuttings). More about asexual reproduction here. PowerPoint about Asexual Reproduction at SlideShare. Introduction to Reproduction and asexual reproduction at About Biology.

Sexual reproduction occurs in both plants and animals and involves the production of gametes by meiosis. Fertilization (when male and female gametes meet) can be external, as in many marine and freshwater organisms, or internal, as in most terrestrial vertebrates, such as birds, reptiles and mammals.  

Sexual Reproduction in Animals, more about reproduction and more about meiosis at About Biology.

Reproduction in Flowering Plants