SENESCENCE AND PROGRAMMED CELL DEATH IN PLANTS

SENESCENCE  Every autumn plants changes their colour, after that the loss of leaves can be seen  from deciduous trees. The reason behind this is , because of change in  day length and cooling temperature which triggers developmental process that lead to leaf senescence and death. Senescence and necrosis are two different processes,  although both of them  lead to death of the cells. Necrosis is death brought out by physical...

Read More

GLYCOLYSIS

Glycolysis Glycolysis  derives its name  from the Greek words "glycos"- sugar and "lysis" - splitting. In this process , Glucose  is converted into two molecules of Pyruvate or pyruvic acid, an organic acid. Apart from preparing substrate for Citric acid cycle, the other function of this is to yield chemical energy in the form of ATP and NADH. Glycolysis occurs in all living organisms (prokaryotes and eukaryotes). Generally ,the...

Read More

SEED DEVELOPMENT AND GERMINATION

The life of an individual plant begins when an egg nucleus in maternal organ of a flower is fertilized by a sperm nucleus to form a zygote. Growth and differentiation of the zygote produces an Embryo, contained in a protective structure called Seed. When the seed gets appropriate conditions, the embryo within the seed will renew its growth and  will continue to develop into a mature plant. SEED DEVELOPMENT Seed is a mature embryo surrounded...

Read More

DOUBLE FERTILIZATION

Structure of the flower Flowers vary enormously in their structures,yet all flowers follow the same basic plan . A generic flower consists of 4 whorls or circles. The two outermost- the Sepals and the Petals , are vegetative structures. The two innermost- the Stamens and the Pistil ,are the male and female reproductive structures. At the base of pistil or female structure is the ovary ,which contains one or more ovules. DOUBLE FERTILIZATION STAGE...

Read More

TRANSPIRATION

TRANSPIRATION  Plant absorbs a large quantity of water from soil,and it is translocated through the plant and eventually lost to the surrounding atmosphere. The process by which water is lost from the plant into the surrounding atmosphere in the form of water vapor,is called TRANSPIRATION. All of the water absorbed by the plants,less than 5% actually retained for growth and even less is used biochemically. Although a small amount of water...

Read More

PLANT SECONDARY METABOLITES

METABOLITES  They are intermediates or products of metabolisms. Plant produces 2 types of metabolites. Primary metabolites Secondary metabolites PRIMARY METABOLITES A primary  metabolite is a kind of metabolite that is  directly involved in plant growth, development and reproduction.Ex- photosynthesis,respiration,solute transport,translocation,protein synthesis,nutrients assimilation,differentiation,formation of carbohydrates...

Read More

VERNALISATION

Plants have evolve the ability to alter their developmental programme in response to environmental stimuli.  A major switch in the development programme is the transition to flowering. Photoperiod and temperature play an important role in determining the  correct time to flower. Vernalisation is also called  as Chilling treatment/ Cold treatment. Many flowers don't come to flower before they experience a low temperature.  These...

Read More