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

Why is a man’s voice usually lower than a woman’s voice, Q. Why is a man’s ...

Q. Why is a man’s voice usually lower than a woman’s voice? Pitch of the voice-how low or high it sounds-it depends on the length, tension and thickness of the vocal cords. As

Explain the culture media and its types, Explain the Culture Media and Its ...

Explain the Culture Media and Its Types? A culture medium (Pl. media), we already know, is a solid or liquid preparation containing all the nutrients required by microorganisms

Explain about vitamin D, Vitamin D (Calciferol - vitamin D2) The main f...

Vitamin D (Calciferol - vitamin D2) The main forms are Vitamin D2 (ergocalciferol-plant origin) and vitamin D3 (cholecalciferol-animal origin). Vitamin D2 forms colourless, aci

What is the molarity of the solution, The molecular weight of "Y" is 200. I...

The molecular weight of "Y" is 200. I use 10g of "Y" in 10mL of water. What is the molarity of this solution of "Y"? What percentage solution of "Y" is it?

What are some examples of biological activities, What are some examples of ...

What are some examples of biological activities in which osmosis plays an important role? Hemolysis (destruction of red blood cells) by entrance of water, the hydric regulation

Chromosome jumping, Chromosome jumping is the technique whereby one begins...

Chromosome jumping is the technique whereby one begins with a piece of DNA from one area of a chromosome, and obtains clones from nearby areas without cloning everything in betwee

Slow moving waters - biota of rivers, Slow Moving Waters - Biota of Rivers ...

Slow Moving Waters - Biota of Rivers The habitat of a slowly moving part of the river is very different from the one just described. Here the water flow is comparatively slow

Lungs - respiratory organs, Lungs - Respiratory Organs In arachnid art...

Lungs - Respiratory Organs In arachnid arthropods such as scorpion and spider, respiration takes place by means of book lungs. There are four pairs of these structures in the

Explain kingdom plantae, Kingdom Plantae The kingdom plant are includes m...

Kingdom Plantae The kingdom plant are includes multicellular eukaryote organisation with photosynthetic nutrition. Typically cell has cellulose wall, sap vacuole, plastids and .

Vasa gene, Vasa are a maternal-effect gene whose product functions in devel...

Vasa are a maternal-effect gene whose product functions in development of the posterior end of the Drosophila embryo.  runt is a non-maternal-effect gene whose product functions in

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