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

Problems of osmoregulation, Problems of Osmoregulation The water, some...

Problems of Osmoregulation The water, some inorganic salts, nutrient molecules are some of the important components of the body fluids. It is essential for the animals to main

Sporophytic and gametophytic self-incompatibility, Sporophytic and Gametoph...

Sporophytic and Gametophytic Self-Incompatibility Besides the categories based on morphology, self incompatibility can be further classified into sporophytic or gametophytic t

Texture of food product, Q. Texture of food product? Texture may be acc...

Q. Texture of food product? Texture may be accessed through touch or mouth feels. When the food is placed in the mouth, the surface of the tongue and other sensitive skin react

Define surgery, Define Surgery? Surgery ! Does the word itself not crea...

Define Surgery? Surgery ! Does the word itself not create a feeling of anxiety and bring our thoughts towards a debilitating state of health which would be accompanied by pain,

Topic test, In what way do investigations build scientific knowledge?

In what way do investigations build scientific knowledge?

Post-operative care of cardiac surgical patients, POST-OPERATIVE CARE OF PA...

POST-OPERATIVE CARE OF PATIENTS The first few days following cardiac operations are the most critical in terms of the patient's survival. The safety with which a patient can

Why water is considered a universal solvent, Water is considered a universa...

Water is considered a universal solvent because- Select one: a. it can dissolve polar and non-polar compounds b. it can dissolve both positively and negatively charged ion

Describe the two kind of fermentation, Q. What are the two kind of fermenta...

Q. What are the two kind of fermentation? What are their complete chemical equations? The two major types of fermentation are alcoholic fermentation and lactic fermentation.

Oestrous cycle, OESTROU S CYCLE - Also known as heat period. Common in...

OESTROU S CYCLE - Also known as heat period. Common in rabbit, cat, dog, sheeps. In this period desire for copulation occur. Possibility of fertilization is 100%.

How do foods and animals become contaminated with dioxin, Normal 0 ...

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

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