abhinash123.pptx

Population

1. Unitary and modular population PRESENTED BY:- ABINASH SONOWAL CLASS :-B.SC 1 ST SEM ROLL NO:-16 HONOURS:-ZOOLOGY YEAR :-2022-23

2. INTRODUCTION A population is defined as a group individuals of the same species living and interbreding within in a given area . Members of a population often rely on the same resources, are subject to similar enviromental constraints and depend on the availability of other members to presist over time. There are two types of populations:- Unitary population. Modular population .

3. Unitary Population In unitary population , each individual is derived from zygote ( the product of fertilization of male and female gamete) and the growth of such individuals is determinate and predictable . In unitary organisms (most animals ) there is usually no problem recognizing individuals , becaues they are both genetically and physiologically separate. Many species of plants and invertebrates however, have vegetative propagation to produce new individuals , besides sexual reproduction.

4. Example of Unitary organisms

5. Modular population In Modular populations individuals of these populations exhibit variation in their morphological features. Plants and few animals groups like sponges and corals are examples of modular population .In a plant population, no two individuals will have the same number of brauches , leaves, flowers or fruits.

6. Unitary and Modular Organisms Unitary organisms –individual units such as humans or mice. Modular organisms –organisms that do not come in simple units of individuals -Several grasses that are attached by runners -Corals , bryozoans Plants derived from one zygote can produce new plants or modules a sexually by means of buds on hallow horizontal roots or by stems that touch the ground. Individual plants produced by sexual reproduction are genets. Gemets may be remain linked to the parent or exist individully .

7. Example a)Plants as grass clumps, blackberries ,strawberries, that reproduce asexually . runners or stolons . Often never clear whether it’s a single modular organisms or a ramet b )Animals such as corals,hydroids , byrozoans , and tunicates that reproduce asexuall by budding.Many primitive metazoa ns are loosely organized and from modular Colonies .

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