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

Name the methods for extracting phosphorous, Name the methods for extractin...

Name the methods for extracting phosphorous Phosphorus/phosphate - Phosphorous is estimated as phosphate. Some methods for extracting phosphorous are as follows:   Dyer met

Procedures for diagnosis - restriction enzyme analysis, R e striction...

R e striction enzyme analysis: The restriction endonuclease analysis of viral DNA fragments or DNA fingerprinting discovered in 1970s has revolutionized the study o

Predict whether narrowing or widening of the blood vessels, Body temperatur...

Body temperature is homeostatic ally regulated around a set point. Given your knowledge of negative feedback and homeostatic control system, predict whether narrowing or widening o

What are the values of dpd for plant cells under hypertonic, What are the v...

What are the values of DPD for plant cells under hypertonic, isotonic and hypotonic media? In plant cells under hypertonic medium there is loss of water for the exterior, SF >

Biological evolution, Natural selection is a process which directs all biol...

Natural selection is a process which directs all biological evolution. It is a process that directs genetic changes which when proved to be adapted to the environment are retaine

Determine the surgical phase of implant therapy, Stage I Surgical phase ...

Stage I Surgical phase Implant placed in the maxilla or mandible After 7 days: - Sutures resorbs or are removed - Patient may be allowed to wear his/her former denture

Describe insulin resistance in non-conventional factors, Describe Insulin r...

Describe Insulin resistance in Non-conventional Factors ? Insulin resistance refers to a generalized metabolic disorder in which various tissues are resistant to normal levels of

Create a dichotomous key for ant, Create a dichotomous key the following or...

Create a dichotomous key the following organisms, ant, butterfly, fly, beetle, grass hopper, wasp, ladybug, roach and dragonfly.

Define general nutritional functions of minerals, Define General Nutritiona...

Define General Nutritional Functions of Minerals? We hear and talk about minerals almost everyday with regards to maintaining good health. But what are minerals and what functi

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