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

St depression at rest, Q. What is ST depression at rest? As early as 19...

Q. What is ST depression at rest? As early as 1965 Ostrand called attention to the syndrome of short PR interval without accelerated conduction and it's association with ST dep

Determine about the prokaryotic cell, Determine about the prokaryotic cell ...

Determine about the prokaryotic cell While we describe in detail the structure of a eukaryotic cell, it will be useful to examine the structural features of a typical prokaryot

Define techniques for detection hidden root canals, Define Techniques for D...

Define Techniques for Detection Hidden Root Canals Three well-angulated periapical films for 3D morphology: o With the cone directed straight on. o Mesiobilque. o And disto

What is intracellular digestion, What is intracellular digestion? Intra...

What is intracellular digestion? Intracellular digestion, or cellular digestion, is the breaking in the interior of the cell of big molecules coming from outside or even from i

Describe austin flint murmur in heart dieases, Describe Austin Flint Murmur...

Describe Austin Flint Murmur in heart dieases? The AR jet may impinge on the undersurface of the anterior leaflet of the mitral valve and push it up, thus creating a relative M

Explain the jejuno ileal bypass and jaw wiring, Explain the Jejuno ileal By...

Explain the Jejuno ileal Bypass and Jaw Wiring? Jejuno-ileal Bypass: Absorptive surface of the small intestines can also be reduced through surgery called the jejuno-ileal by p

Micro-organisms in medicines, In terms of western medicines, over 3000 anti...

In terms of western medicines, over 3000 antibiotics - including penicillin and tetracycline - are obtained from micro-organisms. Another product of micro-organisms i.e. cyclospori

How are gametes formed in the pteridophyte life cycle, Q. How are gametes f...

Q. How are gametes formed in the pteridophyte life cycle, by mitosis or meiosis? What is the type of meiosis that occurs in pteridophytes? In pteridophytes gametes are made by

What is the etiological agent of visceral leishmaniasis, Q. What is the eti...

Q. What is the etiological agent of visceral leishmaniasis? How the disease transmitted and what is are its typical manifestations? The Visceral leishmaniasis is caused by the

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