Question

Describe, in detail, the most likely mechanism or explanation for each scenario described. This can include photosynthesis mechanisms, cellular respiration mechanisms, regulating growth and development: plant hormones, external factors and plant growth, plant nutritions and soils. I am using Raven Biology of Plants 8th edition text book, chapter: 6,7, 27,28, 29, 30

g.  Your apple tree (which is a cutting from one on the old family farm up in the mountains) is healthy and growing, but has never flowered.  A similar cutting planted by your cousin (who still lives up in the mountains) at the same time has flowered regularly for the last five years.

h.  Your corn plants are growing better in sandy soil than in clay soil, even though you’re giving both sets the same amounts of water and fertilizer.

i.  The houseplant that you bought just last week has developed many yellow leaves, some of which are now brown and falling off.  You have been keeping the soil moist but not soggy, there are no signs of pest problems and the nursery swears that all their plants are disease free.

j.  The bean plants on a sloped area in your garden are growing better than the ones that are in a shallow

    depression that holds rainwater.

k.  You place a C₃ plant and a C₄ plant in a well-lit and air-tight container.  Which one will cease photosynthesis first?

Answer 1

H) Sandy soil acts as a good drianage for the plant. If the soil taken is sandy organic matter will help in retaining the nutrients and moisture these are very important for the good plant growth.

But in the case of clay soil or heavy soil, the organic matter will be driven into the compact particles of the soil and loosen it and improves it's drainage ( no retension of nutrients and moisture in this case ).

I) well there are many reasons for it. First is due to lack of sunlight. Keep the plant in sunlight or artificial light. Secondly there may be a nitrogen deficiency, too much calcium in water. And last reason may be due to over wintering ( keeping the plant in cold for a long time.

J) sloppy areas of bean plants. Recieve maximim amount of sunlight enhancing the growth of plants.

K) as the plants are in air tight container, the concentration of carbon dioxide increase.

As the C4 plants cease photosynthesis beyond the limit of 360micron per litre they will die or photosynthesis ceases first. But C3 plants get Saturated beyond the limit of 450micron per litre.

Hence C4 plants will cease first.

G) first reason may be due to over pruning

Second as you stated that ur cousin lives in hills temperature plays a crucial role in flowering . Some apple trees can bear upto -40° celcius. So cold climate is very much important factor to flower.