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

Explain methods of protein estimation, Explain Methods of Protein Estimatio...

Explain Methods of Protein Estimation? Several methods for protein estimation are available. These methods are based on several analytical characteristics of the protein. Labor

Why is it not correct to assert that dna self-replicates, Why is it not cor...

Why is it not correct to assert that DNA self-replicates? DNA is not completely autonomous in its duplication process because the replication does not happen without enzymatic

Transcription of a eukaryotic protein-coding gene, 1. Describe how the vari...

1. Describe how the various molecular mechanisms act to regulate transcription of the genes within the lactose operon of E. coli . 2. Transcription of a eukaryotic protein-codi

What is working memory, Q. What is Working Memory? Working Memory: It h...

Q. What is Working Memory? Working Memory: It has often been suggested that memory does not always work in three stage sequence and the model of memory system comprising of sen

Define key concepts and facts of polysaccharides, Define Key Concepts and F...

Define Key Concepts and Facts of Polysaccharides? 1. All polysaccharides contain several monosaccharide units. 2. All monosaccharide units are joined to each other by glycosidi

Prokaryotes and eukaryotes, Prokaryotes and Eukaryotes By now, you kno...

Prokaryotes and Eukaryotes By now, you know that cell theory holds good for all living forms. However, if you examine under the microscope, the cells of a bacterium, a blue gr

What is the concept of lophophore, What is the concept of Lophophore? A...

What is the concept of Lophophore? A unique double ring of hollow ciliated tentacles that surround the oral opening in some animal phyla. There is some debate as to whether the

Becoming online tutor, how can i work with u as an online biology tutor?

how can i work with u as an online biology tutor?

Define the term - soil heterogeneity, Define the term - soil heterogeneity ...

Define the term - soil heterogeneity The ratings seem rather arbitrary and empirical but are meant to get a reasonable yield. Outputs for different doses of fertilizers are obt

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