Senescence, Biology

Assignment Help:

Senescence

Plants begin their development after seed germination. They grow, flower and finally senesce and die. The period from the start to death is called the longevity or age or life span and this period varies from species to species. For example, some plants, like annuals, complete their life cycles within a few months whereas others live for a few centuries. For example, the life of Juniperus scopulorum is around 3,000 years. The period just before death is called the senescent period.

This may be compared to old age in animals. In this period deterioration occurs because there is a consistent decrease in viability and increase in vulnerability. This phase can be prolonged but cannot be reversed. Senescence may occur very quickly or may be a very slow process. In a plant sometimes the individual organs senesce while the whole plant may remain healthy. In annuals, the whole plant dies; in biennials, the plant dies only after two years, whereas in perennials, year after year the leaves and fruits are shed but the main plant survives.


Related Discussions:- Senescence

Phylum arthropoda - classification of multicellular animals, Phylum Arthrop...

Phylum Arthropoda - Classification of Multicellular Animals Earlier you known how the coelom evolved and the body of the coelomates got segmented leading to evolution of segme

Define sodium, Define Sodium, Potassium and Chloride - Minerals? Claude...

Define Sodium, Potassium and Chloride - Minerals? Claude Bernard was the first to draw attention to the internal environment (milieu interior), referring to the extracellular f

Sexual reproduction, SEXUAL REPRODUCTION You must be aware that reproduct...

SEXUAL REPRODUCTION You must be aware that reproduction is one of the distinguishing features of living beings. Reproduction is basically of two types: asexual and sexual. In ase

Genetic, 1. The genes for ruby eyes (rb), tan body (t) and cut wings (ct) a...

1. The genes for ruby eyes (rb), tan body (t) and cut wings (ct) are all found on the X-chromosome of Drosophila melanogaster. All of these are recessive traits. They map in the or

Determine recommended nutrient intakes by selenium, Determine recommended n...

Determine recommended nutrient intakes by selenium? The FAO/WHO 2004 recommendation for nutrient intake for selenium by groups is given in Table. How do these recommendations c

What are the stages into which photosynthesis is divided, What are the stag...

What are the stages into which photosynthesis is divided? Photosynthesis is separated into the photochemical stage, or light reactions, and the chemical stage. Photosynthesi

Parasitology, how trematodes/nematodes adapt to their parasitic mode of fee...

how trematodes/nematodes adapt to their parasitic mode of feeding

Species diversity indices, From an ecological point of view, species richne...

From an ecological point of view, species richness alone has limited value. More meaningful measures use the number of different species in a given area (species richness) as well

What is the structural representation of a carboxyl group, What is the stru...

What is the structural representation of a carboxyl group? Carboxyl groups have a carbon attached to single hydroxyl group by a simple bond and to one oxygen by a double bond.

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