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

Modes of respiration, Modes of Respiration Many small organisms obtain...

Modes of Respiration Many small organisms obtain oxygen by diffusion through their body surfaces. They do not have any specialised respiratory organs nor do they have blood ci

What is the typical biological function of the tissues, What is the typical...

What is the typical biological function of the connective tissues? How is this function associated to the main features of its cells? The typical function of the connective tis

Pre-operative planning and implant exposure, Q. Pre-operative Planning and ...

Q. Pre-operative Planning and Implant Exposure? A hollow acrylic transitional restoration should be fabricated based on the original diagnostic preview with respect to the toot

Physical environment and genetics, Physical Environment and Genetic Phy...

Physical Environment and Genetic Physical Environment : Safe water and clean air, healthy workplace, safe houses, communication and roads all contribute to good health. The

Define Types of plants and animal on earth - taxonomy, Define kinds of plan...

Define kinds of plants and animal on earth - Taxonomy? Taxonomic studies have major objective-the learning of the kinds of plants and animal on earth, their names, their distin

202, sizes in some biological systems glucose

sizes in some biological systems glucose

Is calcium-sensing receptors serves as a sensor, Which of the following ser...

Which of the following serves as a sensor, or as part of a sensor, that functions in a positive feedback system? A. CaSRs (Calcium-Sensing Receptors) situated in the plasma mem

What is a population, What is a population? The population is a set of ...

What is a population? The population is a set of individuals of the same species found in a given place in a given time.

Explain the spectrophotometer or colorimeter, Explain the Spectrophotometer...

Explain the Spectrophotometer or Colorimete? These can be used to measure the microbial growth or can be used in various microbial and biochemical assays. Figure illustrates 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