What does germination mean in science

what does germination mean in science

Life cycle

This rapid germination again suggests that these concentrations provide better conditions for the germination of the germination of the broad bean seeds. Out of the two, however, % had the greatest number of germinations, and they occurred faster, with 3 germinations on the fifth day, compared to 2 from the % group. germination: The initial stages in the growth of a seed to form a seedling. The embryonic shoot (plumule) and embryonic root (radicle) emerge and grow upward and downward, respectively.

Life cyclein biologythe series of changes that the members of a species undergo as they pass from the beginning of a given developmental stage to the inception of that same how to cook a english roast stage in a subsequent generation.

In many simple organisms, including bacteria and various protistshow to make mango kulfi with condensed milk life cycle is completed within a single generation: an organism begins with the fission of an existing individual; the new organism grows to germinwtion and it then splits into two new individuals, thus completing the cycle.

In higher animals, the life cycle also encompasses a single generation: the individual animal begins with the fusion of male and female sex cells gametes ; it grows to reproductive maturity; and it then produces gametes, at which point the cycle begins anew assuming that fertilization takes place.

In most plantsby contrast, the life cycle is multigenerational. An individual plant begins with the germination of a sporewhich grows into a gamete-producing organism the gametophyte. The gametophyte germinztion maturity and forms gametes, which, following fertilization, grow into a spore-producing organism germinaton sporophyte.

Upon reaching reproductive maturity, the sporophyte produces spores, and the cycle starts again. This multigenerational life cycle is called alternation of generations; it occurs in some protists and fungi as well as in plants. The life cycle characteristic of bacteria is termed haplontic. This term refers to the fact that it encompasses a single generation of organisms whose cells are haploid i. The one-generational life cycle of the higher animals is diplontic; it involves only organisms whose body cells are diploid i.

Organisms with diplontic cycles produce sex cells that are haploid, and each of these gametes must combine with another gamete in order to obtain the double set of chromosomes necessary to grow into a complete organism. The life cycle typified by plants is known as diplohaplontic, because it includes both a diploid generation the sporophyte and a haploid generation the gametophyte. Life cycle. Additional Info. More About Contributors Article History.

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Britannica Quiz. Biology Bonanza. What does the word "migration" mean? How many sets of legs does a shrimp have? From poisonous fish to biodiversity, learn more about the study of living things iin this quiz.

Get a Britannica Premium subscription and maen access to exclusive content. Subscribe Now. Learn More in these related Britannica articles:. The stages of the life cycle of primates vary considerably in duration. Among the most primitive members of the group, these stages are broadly comparable to those of other mammals of similar size. Higher in the phylogenetic scale, they are substantially extended. Nutritional needs and concerns vary during different stages of life. Selected issues are discussed below.

The life cycle of all tracheophytes vascular plantsbryophytes mosses and liverwortsand many algae and fungi is based on an alternation of generations, or different life phases: the gametophyte, which produces gametes, or sex cells, alternating with the sporophyte, which produces…. History at your fingertips.

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Life cycle, in biology, the series of changes that the members of a species undergo as they pass from the beginning of a given developmental stage to the inception of that same developmental stage in a subsequent generation. Learn more about life cycles. Jan 01,  · The mean value of Cd was high at control site and was low at disposal site. The mean value of Cd at control site was ug g ?1 while it was ug g ?1 at dumped site. A significant difference was observed in the mean values of Cu, Ni, Cr and Zn at both sites. The latest health and science news. Updates on medicine, healthy living, nutrition, drugs, diet, and advances in science and technology. Subscribe to the Health & Science podcast.

Names have been removed for privacy This document is in no way endorsed by the IBO, nor should it be used as such. This work remains the intellectual property of the original author.

While you are free to seek guidance from this work, it should not be replicated in any manner for submission as IB assessment. This would be regarded as plagiarism and lead to cancellation of your diploma. This IA had a significant amount of background information, however it is important to remember that this is not necessary to receive full marks.

This IA is not perfect and should not be used as a formula for increasing your marks. Name Biology: Design Practical Plant Physiology Will increasing the salinity of the substrate adversely affect the rate of broad bean seed germination? Background Research Before a seed germinates, it goes through a resting period, or dormancy. The germination of the seed is when the embryo resumes growth, bursting through its encasing The Seed Biology Place This coat acts to protect the internal embryo from the elements, parasites and mechanical injury while it is still dormant Washington State University Germination can only take place under particular circumstances, involving suitable temperature, oxygen supply, water and sunlight RCN The time it takes for a seed to germinate varies between species, although this can be sped up by forcing germination through various methods.

Germination begins once the seed is exposed to moisture, but the embryo will die if it withdrawn Moore Dormancy is caused by a number of factors, including incomplete seed development, the presence of a growth regulator, an impervious seed coat, or a requirement for pre-chilling. All these things would be typically overcome in the seeds natural environment. Thus, it is important to maintain water, oxygen and temperature and optimum levels for germination Clegg Temperature is important, as it often affects the presence of germination inhibitors RCN When the temperature in not ideal, these chemicals continue to prevent the continuation of growth of the embryo, to ensure that the seed germinates under favourable conditions for continued growth and metabolism.

The favoured temperature for germination varies greatly between plant species, depending on their environment. Temperature fluctuation as found in nature can also be a factor RTBG If there is insufficient supply of oxygen, germination may not take place Aggie Horticulture Oxygen is a requirement for respiration, meaning that a lack thereof will cause the plant to die soon after germination.

Not all plant species require oxygen for the initial germination; however all show a need afterwards RTBG Before the embryo leaves its casing, there is a large uptake of water, causing the embryo to expand and consequently burst through its casing Washington State University The metabolism of the plant is vigorous when it first emerges, requiring a plentiful supply of water to support this RCN Sometimes, it can also act to remove the germination inhibitor, allowing for germination to take place ABC In all these respects, water is essential for the germination of seeds.

Light is also a factor for some plants, as plants require it for photosynthesis to occur. When buried too deeply, the plants dies soon after germination when it runs out of food supply, which it could not replenish Aggie Horticulture It is not always a requirement for germination itself, but some seeds are sensitive to its availability RTBG All these factors are necessary, as they aid the seed to germinate when conditions are the most favourable for its long term growth and survival ABC When all these things are 3.

Germination is generally agreed to be the point at which the embryo pushes out of the seed encasing RTBG From there, the plant will continue to develop and grow according to its species, producing food through photosynthesis.

Mineral nutrients are crucial for the growth and development of all plants. Legumes, such as broad beans are very efficient nitrogen fixers, adding nutrients to the soil Moore Plants have a tolerance level for the salinity of their substrate, within which they will germinate. Soil and water both have small concentrations of salt naturally present, which plants have developed to tolerate ABC Farming in many areas with non-native plants which have shallow roots have raised groundwater, causing salt to rise to the surface.

Broad beans, Vicia faba, have been cultivated in Europe for over years Blazey They are frost-hardy annuals, hence they tend to be grown in autumn and winter. Since they are adapted to survive heavy frost, they will usually be sown in autumn for flowering before temperatures rise above 20C Blazey For the Australian climate, this is best done from March to May, as they have a germinating temperature of C Moore Question Will increasing the salinity of the substrate adversely affect the rate of broad bean seed germination?

Variables Table 1. Five trials will be done with the following concentrations of solution: 1. Controls Amount of Water All the seeds will be given mL of water at planting, and then were not given any more. They will all be receiving the same amount of water. Water is retained by laying clear plastic wrap over the containers to prevent water evaporating off. Seeds Yates broad bean Vicia faba seeds will be used throughout the entire experiment.

Water The water used on the seeds will be sourced from the same tap for the entire experiment. This is to reduce any variation in levels of chlorine and other substances, which may affect them.

The water will also be of the same temperature as it will be collected from the same source. Sunlight All the seeds will receive the same amount of exposure to sunlight. They will remain in the same area at all times, meaning that there will be no variation between groups. The amount they receive cannot be measured, but as it is constant, it will not be a factor in any difference between the results of each test. Temperature The temperature of the seeds environment will be controlled by keeping the seeds in the same area.

This will mean that there is no variation in temperature between them. This in turn will keep the temperature of the water constant. Substrate The soil used for the experiment was the same for all the trials.

All other substrates, such as soil, would naturally have a low salt concentration, altering the concentration the seeds would be exposed to. Table 1. Setting Up Figure 1. See Appendix A for photograph. Method 1.

The side of each take-away container was marked with the number 1 to 5 with the marker pen, to indicate which concentration it contained. Each container was filled with potting mix to a depth of 2cm. Ten broad bean seeds were placed in each container, pressed into the soil so that they were partially covered by the potting mix.

Washed 1 litre measuring jug then filled with 1 litre tap water, taking care that no parallax error was made in reading. For the first solution, no salt was added, so mL of the water was measured in the mL measuring jug, then poured over the substrate in container marked 1.

Washed the measuring jug, and then filled with 1 litre of tap water from the same source. Exactly 2. This procedure was repeated 3 more times, washing the measuring jug to remove and residual salt.

Once all the samples had been watered, they were placed in an outdoor area. During the day, they received direct sunlight. They were not exposed to any additional artificial light. Clear plastic film was placed over the containers to prevent water evaporating. Air flow was still allowed. The samples were examined daily to see if any of the seeds had germinated.

This was indicated by the rupture of the encasing and a visible plant root. The total number of germinated seeds was recorded each day for 10 days. Results Table 2. See appendix 1 for original recordings Day Sample 1 0. Observations Evaporated water formed droplets on the plastic film. For the first few days, there was no visible change in the seeds.

After day four, many of the seeds began to germinate, with the tip of the root becoming visible. In sample 3, concentration 0. The reason for this is unclear, as the seed coat was not damaged before planting. After germination, the broad beans plant continued to grow.

The roots were not able to grow down because the substrate was too shallow, so they remained visible. The substrate remained quite moist due to the presence of the plastic film. Processed Data Table 3. Table 3. Figure 3. Graph 3. The graph above makes is fairly clear which salt concentrations best promoted germination. The seeds with 1. The ones with the 0. The other three concentrations 0.

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