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

Do algae reproduce sexually or asexually, Do algae reproduce sexually or as...

Do algae reproduce sexually or asexually? There are algae that replicate sexually and there are algae that replicate asexually. In unicellular algae reproduction is usually

What do you mean by echinodermata, Q. What do you mean by Echinodermata? ...

Q. What do you mean by Echinodermata? You will recall that Pliylum Echinodermata includes spiny skinned animals which are exclusively marine (Gr, echinus : spiny; derma: ski

Explain the function of myosin and albumin, What are respectively some rema...

What are respectively some remarkable functions of myosin, CD4, albumin, keratin, immunoglobulin, reverse transcriptase, hemoglobin and insulin? Myosin is a protein that when a

Explain curdlan, Curdlan Curdlan, a glucan with (1→3) is produced by ba...

Curdlan Curdlan, a glucan with (1→3) is produced by bacterium  Alkaliqenus faecalis  var. myogenes and some related bacteria. It is a tasteless, odorless white powder, which sw

How do chloroplasts multiply, How do chloroplasts multiply? Like mitoch...

How do chloroplasts multiply? Like mitochondria chloroplasts have their own DNA, RNA and ribosomes and they self-replicate through binary division.

Define the concept of health care, Define the Concept of Health Care? W...

Define the Concept of Health Care? We are aware of the fact that health is a fundamental human right. Thus, it becomes imperative for the State to assume responsibility for the

Pesticides - danger to wildlife, Pesticides - Danger to Wildlife Anoth...

Pesticides - Danger to Wildlife Another recently realised danger to wildlife in many parts of the world has come from the development of more effective pesticides. As agricult

Ecology and ecosystem, Ecology and Ecosystem The concepts of environme...

Ecology and Ecosystem The concepts of environment, ecology, ecosystem, energy flow and nutrient cycling in the foundation course on Science and Technology. As you are aware ec

What are typical fauna of the tropical forests, What are the typical vegeta...

What are the typical vegetation and the typical fauna of the tropical forests? In the vegetation of a tropical forest broadleaf evergreen trees predominate. On the top of the t

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