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

Nonsurgical retreatment will be the preferred choice, Nonsurgical retreatme...

Nonsurgical retreatment will be the preferred choice -Less invasive .. not cause problem to the pt. -Less traumatic postoperative .. most probably no post operative pain

Nursing process in infective endocarditis, Nursing Process Nursing Ass...

Nursing Process Nursing Assessment Health history-Past-valvular, congenital or syphilitic cardiac disease/cardiac surgery. Habits-IV drug abuse. Assess the signs an

Hassan, function of epithelial tissue

function of epithelial tissue

List the benefits of exercises, List the benefits of exercises. Benefit...

List the benefits of exercises. Benefits of exercise are : - improves sugar control - decreases HbA1c level - decreases  blood pressure - decreases triglyceride lev

Explain the term lipids, Explain the term Lipids? If somebody discovers...

Explain the term Lipids? If somebody discovers that you have some knowledge of nutrition, you will be promptly shooted with two questions, first, "Oh! You really can tell how m

Explain environmental resistance and the population growth, What is the rel...

What is the relationship among environmental resistance and the population growth according to the biotic potential curve and the real population growth curve? The difference

Determine the nutritional and functional role of selenium, Minerals:- Sele...

Minerals:- Selenium  Food Source       Sea food, organ meats, cereals (levels vary depending on soil levels) Nutritional Functional role Essential nutrient: Keshan

State the term - rCBF, State the term - rCBF In rCBF, the participant i...

State the term - rCBF In rCBF, the participant inhales a small amount of a radioactive gas such as xenon, which is absorbed into the bloodstream and thus transported around the

Define ecosystems science and large-scale ecology, Define Ecosystems scienc...

Define Ecosystems science and large-scale ecology? Many of today's most pressing problems are regional or global in nature including for instance, the effects of land cover and

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