Introduction:
Seed germination is a process where the quiescence seed imbibed with water, the seed radical elongates and breaks through the seed coat surrounding the embryo. However, most of the plant seeds do not germinate immediately and they under goes period of dormancy. These dormant seeds are normally dehydrated, containing inactive enzymes and resistant to unfavorable condition. These characteristic allowed the seed to be dispersed before germination occur and survive adverse environmental condition such as drought.
In order for a seed to break its dormancy, optimum conditions were required for seed to germinate. There are three important conditions for seeds to germinate: suitable temperature, sufficient water supply, and also satisfactory level of oxygen. Water supply is important as it is used to rehydrate the seed tissues and induce breakage of the seed coat which posted as a physical barrier for radical to elongate (Debeaujon et al., 2000). Besides that, oxygen is also an essential element for seed germination because aerobic respiration of the seed tissues produces energy, ATP, which is required for further development of embryo. The optimum temperature for potential seed germination varies on plant species but it is one of the important factors that affect seed germination. Factors such as light and hormones also contribute in seed germination process. The exposure of light is critical for certain plant seeds to germinate, furthermore, light have an indirect effect to the surrounding temperature. Hormones are important as they signal the production of enzyme in seed to perform process such as mitotic division, degradation of cell wall, and cell differentiation.
Thus, the aim of this experiment is to investigate the effect of light, planting depth and hormones on seed germination.
Materials and Methods:
In section A, effect of light on seed germination was studied. The materials used in section A was 100 lettuce seeds, 100 green beans, 4 Petri dishes, cotton wool, and 4 filter papers. 2 Petri dishes were labeled as water + light (LS) and water + dark (LS). The other 2 Petri dishes were labeled as water + light (GB) and water + dark (GB). All the Petri dishes were placed with filter paper that was moistened by 2mL of water. Then, 5mL of water is used to moisten the cotton wool which was placed on top of all the Petri dishes. 50 lettuces seeds were placed to each Petri dish that was labeled LS and 50 green beans were placed to each Petri dish that was labeled GB.
Two members of the group were instructed to visit the laboratory each day of the experiment to water and measure the plants (Handout 1). The measurements that were preformed were to be precise and accurate by the group by organizing a standardized way to measure the plants. The plants were measured from the level of the soil, which was flat throughout all the cups, to the tip of the apical meristems. The leaves were not considered. The watering of the plants took place nearly everyday, except for the times the lab was closed. Respective of cup label, the appropriate drop of solution was added to the plant, at the very tip of the apical meristems.
Although, this experiment is not concluded outdoors, it is provided with efficient light that promotes growth. It’s provided with soil, seed, fertilizer, water and NaCl solutions, to test how salinity effects plant growth.
Figure 1 indicates an increasing mortality rate (positive slope) in plants as density increases; Figure 2 shows the corresponding germination rate reflecting the exact opposite trend. Mortality remains zero until 8 seeds are planted (6% mortality), then is reduced to zero at 16 seeds then increases to 14 percent (32 seeds), 32 percent (64 seeds), and more than half (57 %--128 seeds).
The germinating seeds consumed almost no oxygen throughout the experiment in the 10-degree C water bath. I think that this is because when an organism cools down, all of its cellular functions slow down.
Seed, a book by Lisa Heathfield, applies the idea that knowledge is power, but ignorance is bliss through the character development of Pearl, the deep descriptions of the settings and ambiguity of Pearl’s knowledge on certain scenes. Seed’s narrative quality explores that knowledge does not always make one influential, however, not acquiring knowledge means not feeling conflicted.
Brassica rapa is a mustard plant that can be found throughout North America, and is common in areas undergoing extreme change, such as changes in climate. There is an important relationship between the ecological and genetic factors that influence the growth of Brassica rapa (Mitchell-Olds 1996). So, the environmental elements, as well as the genetic information, are essential to the growth rate and survival of Brassica rapa. This plant is capable of reproducing quickly, and the root systems are usually quite small, although some Brassica rapa have developed larger root systems (Mitchell-Olds 1996). This plant is commonly used in experiments because of its ability to germinate rapidly. Brassica rapa is capable of sprouting within a stage of about two weeks, and this trait allows scientists to perform experiments in a short period of time.
In this experiment I will investigate the affect in which the light intensity will have on a plants photosynthesis process. This will be done by measuring the bubbles of oxygen and having a bulb for the light intensity variable.
Experiment #1: The purpose of this experiment is to investigate the effects of baking soda and light intensity on the rate of photosynthesis of green spinach leave through the observation of floating disk.
· Wear the lab coat all the time in case the acid spills on you.
the effect light has on the growth of pea plants. It will take place in an environment with controlled light, with equal amounts of plants being grown in the light and in the dark. All elements of the experiment other than light will be kept the same, such as amount of seeds in each pot, amount of soil in each pot and amount of water given to each plant each day. This will ensure a fair experiment. Prediction: I predict that in general, the plants grown in the light will grow better than those grown in the dark.
= My aim of this investigation was to check the affect of environmental factors affecting stomatal opening. My experiment was designed to check the stomata opening in light. Plants move in ways that may not seem obvious.
Pod size ranges from 15-30 mm in length, 7-14 mm in thickness, and 2-15 mm in width. Depending on the basal and apical zones as well as the dorsal and ventral regions, pod shape varies from rhomboid, oblong to ovate. The number of seeds per pod ranges from 1-2, with the maximum being three. The seeds are ramhead or owl's-head shaped, and the surface may be smooth or wrinkled. The length of the seed ranges from 4-12 mm and its width from 4-8 mm. The seed mass varies from 0.10 to 0.75 g per seed. The seeds of kabuli type are large (100 seed mass >25 g), round or ram head, and cream colored. The plant is medium to tall in height, with large leaflets and white flowers, and contains no anthocyanin, whereas the seeds of the desi type are small and angular in shape. The seed color varies from cream, black, brown, yellow to green. There are 2-3 ovules per pod but on an average 1-2 seeds per pod are produced. Chickpea seeds germinate at an optimum temperature (28-33°C) and moisture level in about 5-6 days. Germination begins with absorption of moisture and swelling of the seed. The radicle emerges first followed by the plumule.
Light is a very important factor in the rate of photosynthesis, in my project I am going to test that plants do need light in order to photosynthesise. It will be very interesting to see how light will influence the rate of photosynthesis in plants and what will happen if they do not get the required light in order to produce starch .
Seed dispersal is the transport or movement of seeds away from the parent plant in order to help prevent the overcrowding (if this happens plants would not have enough food and light to survive in the area) and help to create new colonies. Thus giving the seed the best chance to germinate in a new location away from the parent plant and hopefully start new colonies. Due to the fact plants have limited mobility they rely on a variety of dispersal vectors to transport their seeds via abiotic (non-living) and biotic (living) vectors. There are five main methods of seed dispersal, animals, gravity, wind, ballistic and water (1). Fire is also another way for seeds to be dispersed but is not as common as the other methods.
In seedless watermelons, rudimentary seed structures form but remain small, soft, white, tasteless and undeveloped tiny seed coats that are eaten virtually undetected along with the flesh of the melon. Seed production for these seedless types is an extremely labor intensive process that makes the seeds relatively expensive. Because germination of these types is often less vigorous than normal types, it is recommended that they be started in peat pots or other transplantable containers. Here the germinating conditions can be closely controlled. Once transplanted, cultivation is similar to that for regular watermelons.