#42 - Aug 2020 - Garden Stuff - © - Sandy Lang - slang@xtra.co.nz
SIZE MATTERSAugust/September: Almost springtime. Hurry. Better to prune late than not. Still just time to plant a tree or shrub. Size & reproduction: We are about 1.7m tall. At a push, 2 of us can produce 12 kids in 25 years. So, our maximum reproduction rate is about 0.24 kids/person/year (12 kids /2 parents /25 years). But small things do much better… Poppies: In 2 years, a poppy seed (1 mm) grows to a plant with ~100 flowers, each flower with 20,000 seeds. This reproduction rate is 1,000,000 seeds/seed/year (100×20,000/2). Poppies make our reproduction rate look silly. Bacteria: And a bacterium (0.002 mm) can divide into two cells every 15 min. At this rate (2, 4, 8, 16, 32, 64, 128 etc for 32 generations) after 8 hours (32 divisions) you have 4,000,000,000 new bacteria. Bacteria make poppy reproduction rate look silly. So, small organisms multiply very much faster than big ones. Surface-area-per-volume: Some more maths. A 1 cm cube has a surface area of 6 cm2 (square cm) and a volume of 1 cm3 (cubic cm), so its surface-area-per-volume ratio is 6 (6/1). But a 2 cm cube has a surface area of 24 cm2 and a volume of 8 cm3, so its surface-area-per-volume ratio is 3 (24/8). Working this calculation for a tiny 0.01 cm cube, we find it has a surface-area-per-volume ratio of 600. Does this matter? YES… Busier: Living processes depend on the movement of stuff (O2, CO2, sugar etc) in and out of cells through the cell surface. So, on a per-volume basis, small plant cells (0.001 cm) can be much busier than large ones (0.01 cm). So, small cells contain more of the important stuff (enzymes, antioxidants) than large ones (usually just sugar storage). So, you are better to eat small plant cells than large ones. So, fruit skin is more nutritious than fruit flesh (10-times more nutritious because the skin cells are 10-times smaller). So, if you must peel a fruit, eat the skin and reject the flesh (apples, grapes, tomatoes). It’s better for you… And eat small fruits: The same geometry tells you that small fruits (blueberries, grapes) have more skin per flesh than big fruits (apples, pears). So, eat small fruits over large ones. And eat small apples over large apples. ___________________________________
SIZE MATTERSAugust/September: Almost springtime. Hurry. Better to prune late than not. Still just time to plant a tree or shrub. Size & reproduction: We are about 1.7m tall. At a push, 2 of us can produce 12 kids in 25 years. So, our maximum reproduction rate is about 0.24 kids/person/year (12 kids /2 parents /25 years). But small things do much better… Poppies: In 2 years, a poppy seed (1 mm) grows to a plant with ~100 flowers, each flower with 20,000 seeds. This reproduction rate is 1,000,000 seeds/seed/year (100×20,000/2). Poppies make our reproduction rate look silly. Bacteria: And a bacterium (0.002 mm) can divide into two cells every 15 min. At this rate (2, 4, 8, 16, 32, 64, 128 etc for 32 generations) after 8 hours (32 divisions) you have 4,000,000,000 new bacteria. Bacteria make poppy reproduction rate look silly. So, small organisms multiply very much faster than big ones. Surface-area-per-volume: Some more maths. A 1 cm cube has a surface area of 6 cm2 (square cm) and a volume of 1 cm3 (cubic cm), so its surface-area-per-volume ratio is 6 (6/1). But a 2 cm cube has a surface area of 24 cm2 and a volume of 8 cm3, so its surface-area-per-volume ratio is 3 (24/8). Working this calculation for a tiny 0.01 cm cube, we find it has a surface-area-per-volume ratio of 600. Does this matter? YES… Busier: Living processes depend on the movement of stuff (O2, CO2, sugar etc) in and out of cells through the cell surface. So, on a per-volume basis, small plant cells (0.001 cm) can be much busier than large ones (0.01 cm). So, small cells contain more of the important stuff (enzymes, antioxidants) than large ones (usually just sugar storage). So, you are better to eat small plant cells than large ones. So, fruit skin is more nutritious than fruit flesh (10-times more nutritious because the skin cells are 10-times smaller). So, if you must peel a fruit, eat the skin and reject the flesh (apples, grapes, tomatoes). It’s better for you… And eat small fruits: The same geometry tells you that small fruits (blueberries, grapes) have more skin per flesh than big fruits (apples, pears). So, eat small fruits over large ones. And eat small apples over large apples. ___________________________________