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

What do you mean by pericardium, Q. What do you mean by Pericardium? Pe...

Q. What do you mean by Pericardium? Pericardium is the sac covering the heart. Pericardium consists of two layers-the visceral pericardium (epicardium) and the parietal pericar

Respiration, How does Respiration in animals

How does Respiration in animals

Why the l enantionmer is more dominant, In the Miller-Urey experiment, amin...

In the Miller-Urey experiment, amino acids of bothe the L and D enantionmers. Why is it that the L enantionmer is more dominant in living things?

Define the antigen-presenting cells of the immune system, Q. What are the a...

Q. What are the antigen-presenting cells of the immune system? The antigen-presenting cells of the immune system also known as APC cells are cells that do digestion and phagocy

Illustrate meiosis ii and meiosis i, Q. How many cells are made after meios...

Q. How many cells are made after meiosis II and meiosis I? After meiosis II four cells are created, After Meiosis I two cells with already separated homologous are created

Epimorphic regeneration, Epimorphic Regeneration In this sort of regen...

Epimorphic Regeneration In this sort of regeneration the lost part is reformed and restored via the growth of a bud or blastema from the remaining part of the organism followe

State the the amount of the nutrient, State the the amount of the nutrient ...

State the the amount of the nutrient On increasing the amount of the nutrient the yield increases and the decrease from the maximum i.e., (A-y) becomes less. Subsequent additio

Classification based on digestive fate of carbohydrates, Explain Classifica...

Explain Classification Based on Digestive Fate of Carbohydrates? The digestive fate of carbohydrates depends on their inherent chemical nature (monosaccharide composition and t

Define the term - lamellac, Define the term - lamellac The inner membr...

Define the term - lamellac The inner membrane is folded into very closely packed membranes called the lamellac. The lamellae flatten out at regular intervals into structures c

Explain alternate photosynthetic pathways, Explain Alternate Photosynthetic...

Explain Alternate Photosynthetic Pathways? An alternate photosynthetic pathway is the C4 pathway, where plants incorporate carbon into four-carbon compounds instead of 3PG. Thi

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