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

What does s-shaped pattern of population growth show, What does S-shaped pa...

What does S-shaped pattern of population growth show? How is J-shaped pattern dissimilar from it and why?

Explain dental care delivery system, Explain Dental Care Delivery System ...

Explain Dental Care Delivery System In the dental care delivery system: there are: patients, insurance payers and dentists For patients: Success = function + esthetics

What is eutrophication in ecology explain briefly, What is Eutrophication i...

What is Eutrophication in ecology explain briefly? Freshwater ecosystems demonstrate the close relationship between aquatic and terrestrial ecosystems. Until recently, most peo

Enumerate the advantages of implant supported prosthesis, Q. Enumerate the ...

Q. Enumerate the advantages of implant supported prosthesis over a removable one Removable soft tissue-borne partial dentures have one of the lowest patient acceptance rates in

Enumerate the important surgical anatomical structure, Enumerate the import...

Enumerate the important surgical anatomical structures in maxilla and the structures present in the posterior wall of the maxillary sinus. The important surgical anatomic struc

Where does the water resorbed after glomerular filtration, Q. Where does mo...

Q. Where does most of the water resorbed after glomerular filtration go? What are the other substances resorbed by the nephron tubules? Only 0.5 to 1% of the glomerular filtrat

Oogenesis., write breif notes on oogenesis

write breif notes on oogenesis

What are the allele frequencies, You observe the following numbers of indiv...

You observe the following numbers of individuals of each genotype in a population: AA 700 Aa 200 aa 100 a.) what are the observed genotype frequencies in this populaiton?

Determine condensation foam method, Determine condensation foam method ...

Determine condensation foam method In the condensation method a pressurized solution is suddenly released  to expand the number of gas bubbles which their ripe through the liqu

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