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

Define function of thiamin as regulator of enzyme activity, Define Function...

Define Function of thiamin as Regulator of enzyme activity? Thiamin regulates the enzymes involved in carbohydrate metabolism. These are: a) Pyruvate dehydrogenase, which pr

Disorder of parathyroid function, Disorder of Parathyroid Function: Th...

Disorder of Parathyroid Function: The disorders of parathyroid function may  either  lead  to increased production or decreased production of parathormone.  Hypoparathyroid

Fluids requirement in ulcerative colitis, Q. Fluids requirement in ulcerati...

Q. Fluids requirement in ulcerative colitis? Fluids: A liberal intake of fluid should be given to prevent dehydration. The passage of at least 1200 ml of urine indicates that a

What are the main human blood group systems, What are the main human blood ...

What are the main human blood group systems? In humans the major blood group systems are the ABO system, the Rh system and the MN system.

Pericardium, The heart is enclosed in a membranous sac called the pericardi...

The heart is enclosed in a membranous sac called the pericardium. It has two layers- the fibrous pericardium which is the outer layer and the serous pericardium that lies inside th

Explain about the cyanocobalamin, Explain about the Cyanocobalamin (vitamin...

Explain about the Cyanocobalamin (vitamin B 12 )? Vitamin B 12 (cobalamin, cbl) is a unique vitamin in human nutrition, since its malabsorption leads to the fatal syndrome of

Polychaetes - feeding and digestion in annelids, Polychaetes - Feeding and ...

Polychaetes - Feeding and Digestion in Annelids Polychaetes involve both free moving (errant) and sedentary species. The free moving species are usually macrophagous and the s

Why organism that can not exist in the presence of oxygen, organism that ca...

organism that can not exist in the presence of oxygen ?

Explain chronic infections fever, Explain Chronic Infections Fever Chr...

Explain Chronic Infections Fever Chronic  Infections Fever: These are generally of longer and sustained duration. The patients have a past history of repeated episodes or con

Mechanisms of neural plate formation, Mechanisms of Neural Plate Formation ...

Mechanisms of Neural Plate Formation You are familiar with the concept that the neurulation comprises of two processes i) The neural plate formation and ii) The neural t

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