Page 124 - Data Science class 11
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The average reaction time for a human is about 250 milliseconds—which means, it takes about a quarter of a second, after
you see something, to physically react to it.
2.4 actIvIty-1
2.4.1 characteristics of radish Seeds
Radish (Raphanus sativus) belongs to the Brassicaceae or mustard family. Following are their characteristic traits:
• Radishes can be easily grown, no matter what the size of the garden is.
• They are fast growing as these seeds take only about 4 to 10 days to germinate.
• They require optimal soil temperature range, humidity and air circulation for their germination.
• It is difficult to germinate radish seeds indoors and transplant outdoor later. It is preferable to germinate these seeds
directly in the soil outdoors.
2.4.2 Step-by-Step approach to Grow radish
Here is a step-by-step approach to grow radish:
• Plant a first sowing of radishes as soon as the garden's soil is workable in the spring. A light and well-drained soil with
a pH of 5.8 to 6.8 will be suitable for best production.
• Throw the seeds onto the ground and cover with only half an inch of soil, then water them regularly as these seeds
grow.
• Radishes require 22 to 70 days to come to harvest. Harvest must be completed before the weather grows warm.
2.4.3 the effects of different duration of Light on the
Growth of radish Seedlings
Though sunlight is required for radish seeds to grow, it is not needed for them to germinate. Sunlight does not affect
seed germination because the seeds are underground, and the sun does not come into play until the radish seed plant
has begun to grow above soil. In other words, sun only plays a major role when the radish seed plant has begun to
grow above soil. During this time, six hours of sun a day is sufficient.
A class of biology students in a school were given a question—What are the effects of duration of light on the growth
of radish seedlings? To answer the above question, the students designed and carried out an experiment given below:
Collect/Consider Data
Data were required to be collected to answer the above question. The radish seeds were exposed to three different
treatments—24 hours of light (light), 12 hours of light and 12 hours of darkness (mixed), and 24 hours of darkness.
The above three treatments covered two extreme cases and one medium case.
With the assistance of a teacher, the students agreed to use plastic bags as a growth setup. The plastic bags allowed
the students to observe and measure the seeds' germination without interfering with them. Two layers of moist paper
towels were put inside a clear plastic bag. The paper towels were stapled in a line, about one-third from the bag's
bottom, to hold the paper towel in place and provide a seam to hold the radish seeds.
For the study, one hundred twenty seeds were available. The growth setup allowed only thirty seeds. The class agreed
to use the additional seeds and create a total of four growth setups—one for the light treatment, one for the mixed
treatment, and two for the dark treatment. Thirty seeds were selected randomly and placed along the stapled seam
of the light treatment bag. Next, thirty seeds were again chosen from the remaining ninety seeds and were placed inside
the mixed treatment bag. Finally, thirty of the remaining sixty seeds were randomly chosen and placed inside one of
122 Touchpad Data Science-XI

