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

Aeration, Aeration is the process on which water and air come into contact....

Aeration is the process on which water and air come into contact. It is carried out by spraying water in the form of spray or fountain over air. Aeration achieves the following obj

Skeleton, what are the biological significance of the skeleton?

what are the biological significance of the skeleton?

Antiparkinsonian drugs, Antiparkinsmian Drugs: Antiparkinsonian drugs ...

Antiparkinsmian Drugs: Antiparkinsonian drugs are  the  specific drugs  to treat the extrapynnidal side effects  of  antipsychotic agents.  Anticholinergic drugs  block

Explain the procedure of taking blood pressure, Explain the Procedure of Ta...

Explain the Procedure of Taking Blood Pressure - Explain the procedure to the patient. In case patient is coming for first time to check the blood pressure explain to the patie

Filaments of a sarcomere in a skeletal muscle, Filaments of a sarcomere in ...

Filaments of a sarcomere in a skeletal muscle When the overlap between the thin and thick filaments of a sarcomere in a skeletal muscle is decreasing,    A. The total lengt

What are the major complications of diabetes mellitus, Q. Why do diabetic p...

Q. Why do diabetic patients often undergo dietary sugar restriction? What are the major complications of diabetes mellitus? Diabetic patients are frequently advised to ingest f

What is the endocrine function of the placenta, Q. What is the endocrine fu...

Q. What is the endocrine function of the placenta? The placenta besides being the organ through which the exchange of substances between the fetus and the mother is done also h

Chlorofluorocarbons cause global problem, In what way do chlorofluorocarbon...

In what way do chlorofluorocarbons (CFCs) cause global problems? Chlorofluorocarbons react with and deplete the ozone in the ozone layer. This permits more ultra-violet light f

Explain the oxidative phase of the pentose phosphate pathway, With the help...

With the help of reaction briefly explain the oxidative phase of the pentose phosphate pathway. The oxidative branch of the pathway generates NADPH and pentose-5 phosphate, th

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