How Do Organisms Reproduce?: questions with answers

Individuals can remain alive without reproducing. With no reproduction, no offspring replace the members that die. The species disappears when its last surviving member dies.

The population is likely to die out because none of its bacteria can survive the higher temperature. Useful variation does not appear simply because organisms need it.

Binary fission splits one parent cell into two daughter cells, so Leishmania reproduces by binary fission. Plasmodium forms many daughter cells at once, which is multiple fission.

The small outgrowth is a bud, which grows and separates from the parent yeast cell. This method is called budding. In multiple fission, many daughter cells form within the parent cell.

A cut body piece of Planaria can regenerate into a complete new animal. Humans and dogs can heal wounds, but their cut body pieces cannot form complete new individuals. Yeast reproduces by budding.

Rhizopus spores have thick protective walls that help them survive dry conditions. They are not seeds or fruits.

Tissue culture starts from a small piece of plant tissue, often taken from a growing tip. The tissue grows on a sterile nutrient medium to produce new plants.

Bryophyllum develops plantlets from buds on its leaf margins. These plantlets can grow into new plants without seed formation.

A thin layer of tissue in the placenta separates the mother's blood from the foetus's blood. Nutrients, oxygen and wastes can cross this layer without the two blood supplies mixing directly.

The developing embryo attaches to the thick lining of the uterus. This attachment is called implantation.

The ovary contains ovules. Pollen grains are produced in the anther.

A seed contains a living embryo, a food reserve and a protective seed coat. The embryo develops into the new plant. The food reserve nourishes the developing seedling, and the seed coat protects the seed.

The testes produce testosterone. The urethra is a passage for urine and sperm; it does not produce testosterone.

During menstruation, the uterine lining breaks down and is shed with blood. The release of an ovum from the ovary is called ovulation.

Condoms form a physical barrier that helps prevent sperm and many disease-causing microbes from passing between partners. They reduce pregnancy risk and the risk of many sexually transmitted infections. Oral pills and Copper-T help prevent pregnancy but do not protect against sexually transmitted infections.