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

Cell interactions and ooplasmic determinants, Cell Interactions and Ooplasm...

Cell Interactions and Ooplasmic Determinants Microscopic observations of egg cytoplasm suggests that it is not homogenous in appearance. The observable variations in the cytop

What are the symptoms and signs of pericardial effusion, Q. What are the Sy...

Q. What are the Symptoms and Signs of pericardial effusion? Asymptomatic: Slowly accumulating small to moderate pericardial effusion may not cause significant elevation of intr

Measurement and evaluation of food texture, Q. Measurement and Evaluation o...

Q. Measurement and Evaluation of Food Texture? Kinesthetic characteristics deal with the sense of feel, just like the characteristics of appearance deal with the sense of sight

Define about the cellulose acetate electrophoresis (cae), Define about the ...

Define about the Cellulose acetate electrophoresis (CAE)? If the hydroxyl groups in cellulose are reacted with acetic anhydride, cellulose is acetylated to form the raw materia

Explain structural and functional relationship, Describe the location and s...

Describe the location and structure of the pituitary gland and explain its structural and functional relationships with the hypothalamus.

Explain nucleosides, Nucleosides : compounds formed from a nitrogenousba...

Nucleosides : compounds formed from a nitrogenousbase and  a penstose sugar.

Properties of phytochrome, Properties of Phytochrome Phytochrome is a ...

Properties of Phytochrome Phytochrome is a chromoprotein: this means it is composed of a protein and a chromophore. The chromophore is actually attached to the protein and is

State fluid exchange between blood plasma in a capillary, Which of the foll...

Which of the following statements are true for fluid exchange between the blood plasma in a capillary in the leg and the interstitial spaces surrounding that capillary? A. Bloo

What information must be included on the form, Submission of evidence items...

Submission of evidence items to the forensic laboratory requires that a specific "Evidence Submission Request Form" be completed. What information should be included on the form?

Favus, Favus Fowl favus is a superficial, chronic, sporadic mycotic in...

Favus Fowl favus is a superficial, chronic, sporadic mycotic infection of birds caused mainly by Trichophyton gallinae. Very rarely Trichophyton simii is also involved in 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