Total fertility rate, Biology

Total Fertility Rate

Total fertility rate (TFR) is the total number of children a women can be expected to bear in a given population if birth rates are constant for at least one generation. Replacement level is a value of TFR and is the number of children a couple must have to replace themselves. You might think that two parents would have to have only two children to replace themselves.

The actual average replacement level is, however, slightly higher, primarily because some children die before reaching their reproductive years. In developed countries the replacement level is fixed at 2.1. In developing countries where infant mortality rates are high and life expectancies are short, replacement level is about 2.7. If replacement level is low-below 2 i.e. each couple has children less than those required to replace themselves, then the population will actually decline as in the case of Sweden and Germany.

Posted Date: 1/21/2013 1:42:49 AM | Location : United States







Related Discussions:- Total fertility rate, Assignment Help, Ask Question on Total fertility rate, Get Answer, Expert's Help, Total fertility rate Discussions

Write discussion on Total fertility rate
Your posts are moderated
Related Questions
Secondary Production - Ecosystem The net primary production is the only energy available to consumers or heterotrophs including man. Herbivores such as cow or deer gaze upon

Explain biochemical mediators of calcium metabolism Bone physiology is controlled by an interaction of mechanical and metabolic factors. Under physiologic circumstances, bone

Gaseous Exchange Gaseous exchange is take place on by both mantle and the gills. The gills of most bivalves are highly changed for filter feeding. They are derived from the pr

What is Fluorescent Microscope? In above said microscopes, image is produced from light that passes through a specimen. In fluorescent microscope, however, specimen image is f

Q. What are the major features of fishes associated to the habitat where they live? Fishes are all aquatic animals and thus they have a hydrodynamic elongated body appropriate

Explain about the DNA viruses - Carcinogenic? The three DNA viruses found to cause human cancers are EBV, HBV and HPV. What are these? Let us find out. Epstein-Barr viru

• Cyclins accumulate during the G1, S, and G2 phases of the cell cycle. • By the G2 checkpoint (the red bar in the figure), enough Cyclin is available to form MPF complexes (aggre

Q. As per the Watson - Crick Model how many polynucleotide chains does a DNA molecule have? The DNA molecule is formed by two polynucleotide chains bound in antiparallel mode (


The initial stage of packaging have the binding of the chromosomal DNA to histones.  Whole, in chromosomes the ratio of the DNA to histones on a weight basis is around 1:1. There a