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

Determine the symptoms of campylobacteriosis, Determine the Symptoms of Cam...

Determine the Symptoms of Campylobacteriosis Symptoms:  C. jejuni infection causes diarrhoea, which may be watery or sticky and can contain blood and faecal  leukocytes (white

Find out a mutation in the aldolase b gene, Hereditary fructose interolance...

Hereditary fructose interolance is a rare recessive disorder that is caused by a mutation in the aldolase B gene. As a result of this disorder individuals may have all of the follo

Emergence of contemporary biology, EMERGENC E OF CONTEMPORARY BIOLOGY - ...

EMERGENC E OF CONTEMPORARY BIOLOGY - 1 .       Aristotle (384-322BC) - Greek Classified animal species and arranged them in hierarchies. Formulated 'Great chain of

Difference between "a" and "i" bands, DIFFERENCE S BETWEEN "A" AND "I" BAN...

DIFFERENCE S BETWEEN "A" AND "I" BANDS     A-Ban d (Anisotropic band)   I-Ban d (Isotropic band) 1. It

Plant cells differ from animal cells, State the ways in which (a) all...

State the ways in which (a) all plant cells, (b) some plant cells vary from animal cells.    (a) All plant cells have a cellulose cell wall.  (b) Some plant c

Hydrogen bonds important for making water cohesive liquid, Hydrogen bonds a...

Hydrogen bonds are important for all of the following except:: a) Allowing carbohydrates to dissolve in water b) Stabilizing the three-dimensional shape of proteins. c) Ma

Counselling diabetic travellers, Counselling Diabetic Travellers The c...

Counselling Diabetic Travellers The counsellor needs to educate a diabetic patient and /or his family members to following issues when such patients plan to travel: ·  Plan

Explain about solubility of proteins, Precipitation/Solubility of Proteins ...

Precipitation/Solubility of Proteins Most of the functional properties are  dependent on the degree to which the proteins are soluble. The solubility behaviour provides a good

Arsenic, A r se n i c Arsenic is a widely distributed environmenta...

A r se n i c Arsenic is a widely distributed environmental pollutant that gets released into the environment through industrial processes and agricultural usage. Arsenic c

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