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

Run off-water cycle, Run off Some of the rainfall is soaked into the so...

Run off Some of the rainfall is soaked into the soil and excess water flows over the land surface along the natural slope of the area. Run off is the main source of water for l

Viral diseases, Nature of viral diseases Viral diseases are manifested...

Nature of viral diseases Viral diseases are manifested in acute, sub-acute or chronic forms, as frank clinical cases or as latent infections, some of which are fatal. These di

Determine the architecture of cell, Determine the architecture of cell ...

Determine the architecture of cell There are over 200 types of cells in the human body, which are assembled into a variety of tissues, such as, the epithelia, connective tissue

Which type of genetic disease can be identified, Which type of genetic dise...

Which type of genetic disease can be identified from the visual analysis of the number of chromosomes present in a karyotype? The counting and identification of chromosomes in

Neurochemistry of attention, Neurochemistry of Attention Different neur...

Neurochemistry of Attention Different neurotransmitters systems are implicated in attention. Cholinergic, dopaminergic and serotonergic systems play major roles in neurochemica

Explain about extra low interstitial, Explain about Extra low Interstitial ...

Explain about Extra low Interstitial Extra low Interstitial (ELI) contains low levels of oxygen dissolved in interstitial sites in the metal. Lower amounts of oxygen and iron i

Breathing and exchanges of gases , What happens to respiratory system in a ...

What happens to respiratory system in a man going up a hill?

Explain restrictive cardiomyopathy, Q. Explain Restrictive cardiomyopathy? ...

Q. Explain Restrictive cardiomyopathy? It is a systemic or idiopathic disorder of the myocardium with clinical and hemodynamic features of diastolic dysfunction, closely simula

Lungs, what''s the role of lungs in terms of excretion? Like the trachea wh...

what''s the role of lungs in terms of excretion? Like the trachea what''s its role in excretory system?

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