Measurements in plant growth

We can measure the growth of an organism by measuring its mass, length, height, width and area or volume. Over a period of time, sometimes it's possible to measure just one of an organism such as, the leaf of a plant, but this part must grow in proportion to the complete organism. In the case of seedlings, the number of leaves may be used as a growth indicator. Each of these growth indicators is known as a parameter of growth.
The pattern of growth of an organism would vary with the growth parameter that is used. In growth studies, the parameter used would depend on the type of organism. For example, we can measure the height of maize plant to estimate it's growth, but we cannot use the same parameter to assess the growth of a mouse. The ease of measuring a growth parameter will also determine its usage. Thus, area and volume measurements give an accurate picture of growth but are often difficult to measure and so are rarely used.
Mass and length are the most commonly used growth parameters since they are easy to measure. However, the results obtained may not be very accurate or reliable. For example, a seedlings grown in the dark increases in height more rapidly than a similar seedling in the sunlight but it is the seedling in the sunlight that shows greater growth in terms of an increase in protoplasmic material. Using measurements of mass may also be misleading. If an organism takes in large amount of water its mass may increase temporarily. This, however cannot be considered as growth. In most growth studies mass may be measured as wet mass or dry mass. Wet mass is the mass of the organism under normal conditions. It is not a reliable indication of growth.
Dry mass, is the mass of an organism after all the water in it has been removed. Although measuring growth in terms of dry mass is an accurate and reliable method, the organism get killed in the process. This means that it is not possible to measure growth in the same organism. To study growth by measuring dry mass, we must carry out the study on a large number of similar organisms.

Comments

Natural soil

Natural soils are influenced by rainfall and temperature,heavy rain causes the soil to become leached. High temperatures increase the rate of decomposition of organic matter in the soil, thereby lowering its humus content. Thus, climatic conditions tend to produce poor soils in the tropics and rich soils in the temperate regions. Besides climate and vegetation, the parent rock material also contributes to the quality of the soil. For example volcanic rocks tend to produce fertile soils. Laterite, a red soil which is a product of leaching, is commonly found in the tropics. It is composed mainly of iron and aluminium compounds,and poor in humus and essential plant nutrients, such as phosphorus, nitrogen and potassium. The black and brown soil of the temperate grasslands are the world's richest soils, with a high mineral and humus content. The light coloured desert soils tend to be very rich in minerals but have a low humus content. Mainly the soils ar...

READING AND UNDERSTANDING

All reading is geared to understanding. There would be no point in reading if we did not understand what we are reading. However there are many different obstacles in the way of easy understanding of a passage. It is your task as a reader to actively seek to break down the barriers to understanding. One block to understanding is caused by references in the passage to things that are outside it. Pronoun are the first examples of words that refer to people and objects. Sometimes, it is easy to follow the reference at other times, it is more difficult. Look at the opening sentence of the passage you've just read that begins this way "She was waiting for us:small, dowdy, dirty..." Who was waiting? Who was the person waiting for? (Perhaps you would also like to know why she was waiting.)Answers to these questions will surely help you to understand and thus follow the reference. The first thing to do is to ask questions like the ones we have just asked and to read t...

Frequent masturbation

Frequent masturbation in young men is linked to higher risk of early prostate cancer , but it lowers prostate cancer risk for men in their 50s, a study shows. High levels of male sex hormones, or androgens, may increase a man's risk of prostate cancer . But different studies of this question, done in different ways, have reached different conclusions. To look at the question in a new way, a team of researchers looked at whether men with more intense sex drives were at higher risk of prostate cancer. About half the men got prostate cancer by age 60, and about half did not have cancer . The findings were surprising. Sexual intercourse did not affect prostate cancer risk. But frequent masturbation did -- in different ways, at different times of life. "Frequent masturbation during men's 20s and 30s increased their risk of prostate cancer. For men in their 20s, "frequent masturbation" was two to seven times per week. Compared to same-age men who reported mas...

Newsflashtalk.com Lifestyle, learning, health and food.

Search This Blog