Total fertility rate, Biology

Assignment Help:

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.


Related Discussions:- Total fertility rate

Some species of plant are strongly adapted to pollination, Some species of ...

Some species of plant are strongly adapted to pollination by certain insects.   Characteristics which are regarded as adaptations to pollination by bees are: ( a) white o

What are the hormones secreted by the neurohypophysis, Q. What are the horm...

Q. What are the hormones secreted by the neurohypophysis? What are their respective functions? The neurohypophysis secretes the antidiuretic hormone (ADH) and oxytocin. Oxytoci

What is lactate, What is Lactate Lactate is transported to  the liver...

What is Lactate Lactate is transported to  the liver in  the Cori cycle (lactic  acid cycle)  and is converted to pyruvate. Hepatic gluconeogenesis then converts  lactate  ba

Explain protoderm in primary growth in shoot, Explain Protoderm in primary ...

Explain Protoderm in primary growth in shoot? The protoderm is one of the so-called "primary tissues" because it is formed first during germination and subsequent bud growth an

What are heterochromatin and euchromatin, Chromatin is uncondensed nuclear ...

Chromatin is uncondensed nuclear DNA, the typical DNA morphology in interphase (the phase of the cell cycle in which the cells is not separating itself). In this phase of the cell

What are the two main species of taenias, What are the two main species of ...

What are the two main species of taenias that cause human diseases? The two major species of taenias that cause disease in humans are Taenia solium, or the pork tapeworm, and T

Usefulness of fungi for some industries, Q What is the usefulness of fungi ...

Q What is the usefulness of fungi for some industries? Fungi are industrially used in the production of fermented beverage, cheese, bread, and so on. A few fungi are very impor

Transcription of a eukaryotic protein-coding gene, 1. Describe how the vari...

1. Describe how the various molecular mechanisms act to regulate transcription of the genes within the lactose operon of E. coli . 2. Transcription of a eukaryotic protein-codi

Which substance starts clotting in humans after a wound, When a wound occur...

When a wound occurs in humans, platelets in the blood activate a substance that starts clotting process. The substance which starts clotting is: a) Adenosine (pron: ah-den-ah-s

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd