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

Explain long-term risk estimation, Explain Long-term Risk Estimation ? ...

Explain Long-term Risk Estimation ? Many studies have examined long-term risks associated with risk factors using traditional epidemiological methods. Framingha investigators

Effect on microbial ecology and food spoilage of ph, Q. Effect on Microbial...

Q. Effect on Microbial Ecology and Food Spoilage of pH? The acidity of a product plays an important role in deciding the type microflora present in food and the rate and type o

How hyperventilation affect blood ph, Freediving is an activity in which a ...

Freediving is an activity in which a person dives, sometimes to great depth, without the use of scuba gear. The diver must hold his or her breath for the duration of the dive. (The

Resemble the homozygous recessive parental, A dihybrid cross yields 320 F2 ...

A dihybrid cross yields 320 F2 offspring. How many are expected to resemble the homozygous recessive parental?

Explain tocopherols, Explain Tocopherols These are the most widely dist...

Explain Tocopherols These are the most widely distributed antioxidants in nature, and they constitute the principal antioxidants in vegetable oils.  A relatively high proportio

Tuberculosis, Tuberculosis Tuberculosis is caused by a Bacillus-myco...

Tuberculosis Tuberculosis is caused by a Bacillus-mycobacterium tuberculosis, a gram- positive and acid-fast organism. It is communicable disease. Mode of Transmissio

Nitrates and nitrites- preservative, Normal 0 false false f...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

Determine how to calculate the amount of nitrogen, Determine How to Calcula...

Determine How to Calculate the Amount of Nitrogen? The amount of nitrogen can be calculated for this value using the equation: 1000 ml of 1N H 2 SO 4 = 1000 ml of 1N NH 3

Cranial nerves, The cranial nerves are composed of twelve pairs of nerves...

The cranial nerves are composed of twelve pairs of nerves which emanate from the nervous tissue of brain. In order to reach their targets they should ultimately exit/enter the cr

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