2 describe and explain the latitudinal patterns in dormancy...

2: Describe and explain the latitudinal patterns in Dormancy NC: Greenup Estimated Greenup onset Day of Year Estimated Dormancy onset 50 160 50 Day of Year 310 140 45 45 300 120 40 Latitude 35 40 290 80 35 280 60 30 30 270 40 20 260 -90 -85 -80 -75 -70 -65 -90 -85 -80 -75 -70 -65 Longitude Longitude 1: Describe and explain the latitudinal patterns in greenup 2: Describe and explain the latitudinal patterns in Dormancy

Transcript

00:01 Hello students, in this video we are going to look at a few definitions.

00:03 The first is tropism.

00:07 Tropism is a stimulus response by an organism.

00:13 For example, plants, they grow towards the light.

00:17 The second is photoreautism.

00:23 It is a response to the changes of length of the day.

00:37 Photoperiodism is very important as it allows.

00:39 Flowers to bloom seasonally due to this response that is the changes of the length of day.

00:46 The third is nastic movement.

00:53 Nastic movement is also a stimulus response to touch and one thing to note here is that the response is independent of the touch or of the stimulus.

01:11 The fourth is thigmotropism.

01:19 Thickmotropism is response to stimulus that leads to growth.

01:33 Thygotropism is a response that leads to growth of a plant.

01:36 For example, if the tendril of a plant touches a stick, for example, it will coil around the stick.

01:46 Next is heliotropism.

01:51 Heliotropism is seen in sunflowers wherein the flower or the plant they grow in the direction of land.

02:07 Next is hydrotropism.

02:13 This is a response which leads to growth.

02:16 So a response that leads to growth in the direction of water.

02:28 For example, the roots, the roots they search for water, so they grow in the direction where water is present.

02:34 Now let us look at the mechanisms of responses to various stimuli.

02:46 Now before we come to that we must understand that the response is usually triggered due to a hormone called as oxen.