Natality rate - natality, Biology

Assignment Help:

Natality Rate - Natality

Natality rate or birth rate is determined by dividing the number of individuals born by unit time and is expressed as follows:

Natality rate =  ΔNn / Δt

Δ Nn = production of new individuals in a population

Δ t = unit time

Natality rate can also be determined as the number of new individuals per unit of time per unit of population. This is called specific natality rate and can be expressed as:

Natality rate per unit of population = ΔNn / N Δ t

N may represent the total population or only the reproductive part of the population, i.e. females, for example, in higher organisms natality rate is per female. Natality rate is zero or positive but never negative. The measurement of natality or birth rate is highly dependent on the type of organism being studied. Some species breed once a year, some breed several times a year and others breed continuously. Some produce many seeds or eggs, and others few.

For example, a single oyster can produce 55 to 114 million eggs, whereas birds usually lay between 1 and 20 eggs. Also the specific natality rate differs for individuals of different age groups in the population. For example in a rabbit population for 1 to 2 year old females the specific natality rate is average 4 young ones per year per female, while for females of less than 1 year the rate is 1.5 on an average. Since natality is the concept referring to the population and not to the isolated individuals, the average reproductive capacity should be taken as the measure of natality, and not the capacity of the most productive or least productive individuals.

 


Related Discussions:- Natality rate - natality

Transport into the cytosol, Fatty  acids  are  synthesized  in  the  cytoso...

Fatty  acids  are  synthesized  in  the  cytosol,  but  acetyl  CoA  is  produce  from pyruvate in the mitochondria. Therefore the acetyl CoA must be transferred  from  the mitocho

Duck septicemia (duck pasteurellosis/new duck disease), D uck septicemia (...

D uck septicemia (duck pasteurellosis/new duck disease) The disease is caused by Pasteruella anatipestifer (Syn. Riemerella anatipestifer ) that mostly affects growing duck

What are the major organic molecules for living beings, Q. What are the maj...

Q. What are the major significant organic molecules for living beings? There are many types of organic molecules that are important for the living beings. Particularly importan

Why the effect of genetic drift likely to be the same, Is the effect of gen...

Is the effect of genetic drift likely to be the same in pop 1 and pop 2? How are genetic drift and pop size related? When there is strong selection against the homozygous recessive

Explain the effect of deficiency of pyridoxine, Explain the effect of Defic...

Explain the effect of Deficiency of pyridoxine? A deficiency of vitamin B6 alone is uncommon because it usually occurs in association with a deficit in other B-complex vitamin

Foot-and-mouth disease - viral disease, F o o t - a n d - m o u ...

F o o t - a n d - m o u t h disease Foot-and-mouth disease (FMD) is an extremely contagious viral disease of cloven footed animals most notably cattle, pig and she

What is the difference between smallpox and measles, Q. What is the differe...

Q. What is the difference between smallpox (variola) and measles? The Smallpox is a viral infection like measles. The Smallpox is transmitted by respiratory secretions, saliva

Infectious diseases, what are pathogenic characteristics of protoctista?

what are pathogenic characteristics of protoctista?

Nursing management of rheumatic fever, Nursing Management The overall ...

Nursing Management The overall goals are that patient with RH fever will resume daily activities without Joint pain, reduce the risk of residual cardiac disease, and plan a

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