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

Micro biology, explane the role of nitrogenase enzyme

explane the role of nitrogenase enzyme

Viruses, what is the crystallization of a virus? what is the importance of ...

what is the crystallization of a virus? what is the importance of this process?

Zoonoses disease-ehrlichiosis, Ehrlichiosis The disease is caused by a ric...

Ehrlichiosis The disease is caused by a rickettisia, called Ehrlichia canis. Dogs and man are the reservoir hosts. The infection is transmitted through bite of infected tick, Rhip

In which area lengthening of long bones occurs, Lengthening of long bones i...

Lengthening of long bones in humans takes place in a specific area of the bone. This area is known as the: a) Cancellous bone b) Medullary canal c) Periosteum (pron: per-

Physiological characteristics of molds, Q. Physiological Characteristics of...

Q. Physiological Characteristics of molds? The physiological characteristics of molds will be reviewed only briefly here and will be discussed in more detail subsequently. Mois

Why are glucorticoids used in transplant patients, Why are glucorticoids us...

Why are glucorticoids used in transplant patients? Patients with transplanted organs are prone to host versus graft rejection as their own immune system tends to attack the gr

Photosynthetic function, Photosynthetic function Structural organisa...

Photosynthetic function Structural organisation of the leaf is suitable to perform the process of photosynthesis. Hence leaf is called as a food factory. The leaf has a l

Explain gellan gum, Explain Gellan Gum Gellan is an exopolysaccharide c...

Explain Gellan Gum Gellan is an exopolysaccharide consisting of  β-D-glucose,  β-D-glucuronic acid,  α-L-rhamnose with acetate and glycerate groups, produced by the bacterium S

Define nutritional needs during exercise, Define Nutritional Needs during E...

Define Nutritional Needs during Exercise? During Exercise: Addressing the nutritional needs during training is essential for optimal performance. The focus should be to:

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