All forms of life - from simple to complex - share an ability and instinct to reproduce. Reproduction occurs either sexually through an exchange of genetic material between two organisms, or asexually where organisms replicate producing offspring with an identical genetic makeup to their parent. This program looks at sexual and asexual reproduction, starting at the cellular level, with clear explanations of meiosis and mitosis. Using a range of graphics and footage to explain biological processes, it explores various types of asexual reproduction, including fission, budding, fragmentation, spores, vegetative and artificial propagation. Sexual reproduction in animals is covered - including direct and indirect development - as well as sexual reproduction in flowering plants. Finally, various benefits and disadvantages of both types of reproduction are examined. This is an ideal resource for senior level students of Biology and allied subjects, including Health and Human Development. It explains some difficult concepts well, with effective use of visual media.
In this episode Von Hagens dissects a man and a woman to illustrate the journey of reproduction, and their reproductive systems. Following the path of the sperm from the testis, along the vas deferens and out of the penis, he picks up their journey inside the female dissection specimen where he dissects her uterus and finally demonstrates how a baby passes through the pelvis.
Did you know that there are an estimated 390,900 plant species known to science? This diversity of plant species is, in part, due to sexual reproduction. In plants, sexual reproduction is carried out in the flowers. The flowers contain the sexual organs. Let’s start with labelling the different parts of a flower. The petals and sepals help to protect the flower bud and can be brightly coloured or scented to attract pollinators. The stem and receptacle are the parts that connect the flower to the rest of the plant. The stamen is the male part of the flower. It consists of the anther where pollen is produced and the filament which is the stalk that supports the anther. These structures are responsible for the production and positioning of pollen, the male gamete. The female part of the flower is called the carpel and this consists of three parts: the stigma – a sticky landing for pollen, the style - where the pollen grain descends and the ovary where female gametes or sex cells are located. Within the ovary, ovules produce female gametes.
Extracted from: The Amazing Lives of Plants, by Dr. Larry Jensen
The role of reproduction is to provide for the continued existence of a species; it is the process by which living organisms duplicate themselves. Animals compete with other individuals in the environment to maintain themselves for a period of time sufficient to enable them to produce tissue nonessential to their own survival, but indispensable to the maintenance of the species.
Asexual reproduction is the type of reproduction in which the presence of a sperm and an egg--or any natural equivalent--s not required. It is used by a lot of plants for perpetuating themselves; some species even have the option of reproducing themselves both sexually and asexually, selecting a method based upon the environment that they live in