How well can you predict a child's (adult) height from information about their parents?
The relations between parents' heights and children's heights are only approximate. See Adriana Heguy's answer for the underlying genetics.The Mayo Clinic (Child growth: Can you predict adult height?) provides a method for the approximate prediction:Add the mother's height and the father's height in either inches or centimeters.Add 5 inches (13 centimeters) for boys or subtract 5 inches (13 centimeters) for girls.Divide by two.Most children will reach an adult height within 4 inches (10 centimeters) of this estimation.The average adult male height in the US is about 5' 10", so +/- 4" would be a range from 5' 6" to 6' 2" - pretty wide.Here's a figure comparing a limited set of parents' and children's variations from averages. SDS = Standard Deviation Score. Parents who are 1-2 standard deviations below the mean are likely to have children who are shorter than the mean. And parents who are 1-2 standard deviations above the mean are likely to have children taller than the mean. But, again, the actual range is very large.from The strengths and limitations of parental heights as a predictor of attained height
Best methods to predict height!!?
Well, there is no test that can tell you for sure exactly how tall you are going to be, but the most accurate determinant is the bone age exam. Bone age is assessed by X-rays that indicate how much development has already occurred in the skeleton and how much more is possible; to do this they pay close attention to your growth plates, you'd be surprised what this little area can tell you- if the growth plates are still open, more growth is likely. The closer you are to final height (by virtue of your age or the finding of closed growth plates on X-rays), the better these formulas predict height. The myth that some people believe is that you can double the height when you were 2 years old to determine how many inches you will be when they are at full adult height. If this was the case and your baby was 36 inches at two years old, then they would be 72 inches as an adult, or six feet. So this method is VERY inaccurate. There is actually a formula some go by that can be pretty accurate. It says to add up the parent’s height (in inches) and divide by two to get the average. Then for a girl subtract 2.6 inches and for a boy add 2.6 inches. That means that if mom is 67 inches tall and dad is 73 inches tall, making the total 140 inches, the average is 70 inches. This would make their daughter approximately 5′6″ tall and their son approximately 6′0″ tall. This is not always accurate however because it is possible that a girl might get a short grandmother’s gene as her dominate gene, making her shorter than the formula states she would be. Also, heredity only accounts for about 70% of what goes into deciding how tall someone will be. The other 30% comes from environmental factors, like eating habits (poor nutrition can "stunt" a child's growth) and exercise patterns (a competitive gymnast may not grow to their full potential), and your genes, so it is very common to end up a few inches taller or shorter than your predicted height. Nothing is exact; after all it is all science. Everything is just the expert’s best guesses on how your child will grow through puberty and into adulthood. Good Luck!
How well can you predict a child's (adult) height from information about their parents?
The relations between parents' heights and children's heights are only approximate. See Adriana Heguy's answer for the underlying genetics.The Mayo Clinic (Child growth: Can you predict adult height?) provides a method for the approximate prediction:Add the mother's height and the father's height in either inches or centimeters.Add 5 inches (13 centimeters) for boys or subtract 5 inches (13 centimeters) for girls.Divide by two.Most children will reach an adult height within 4 inches (10 centimeters) of this estimation.The average adult male height in the US is about 5' 10", so +/- 4" would be a range from 5' 6" to 6' 2" - pretty wide.Here's a figure comparing a limited set of parents' and children's variations from averages. SDS = Standard Deviation Score. Parents who are 1-2 standard deviations below the mean are likely to have children who are shorter than the mean. And parents who are 1-2 standard deviations above the mean are likely to have children taller than the mean. But, again, the actual range is very large.from The strengths and limitations of parental heights as a predictor of attained height
What factors affect the motion of a falling object?
The ball will take longer to reach the ground, if it is dropped from a greater height, simply because it has a larger distance to travel. The amount of air resistance is determined by the overall surface area of the ball and parachute, and this does not change. Assuming that the parachute deploys as soon as you release it, then it will reach terminal velocity almost instantly, and continue to fall at a constant speed. To examine the effect of air resistance, you should try parachutes of different surface areas, and compare the fall times. You should use different weights with the same parachute, and compare the results. Try different shapes with the same parachute and compare fall times eg try a cone shape, a cube, a cylinder and so on. Try examining fall times in something other than air, say water, vegetable oil or clear honey, and again, try different shapes and masses.
Do children inherit height from their mother or their father?
Every daughter has exactly 50% of their chromosomal DNA coming from each parent. Every boy has very close to 50%, altered only by inheriting an X from their mother and a Y from their father. The X chromosome, being much larger than the Y, has more DNA, so a son has very slightly more DNA from their mothers, though this is not generally considered significant. There is also some DNA that is not on chromosomes, but carried in an organelle within the cells called the mitochondria, mtDNA. Both sons and daughters exclusively carry their mothers' mtDNA, as it comes from the ova that was fertilised to create them. The sperm have very few mitochondria, and even those that make it into the ova are destroyed after conception, so paternal mtDNA is not passed on to offspring.Having made these two qualifications, even in my college genetics courses, I'm sure that for the sake of brevity, our lecturers used to just say "50% from each parent", because neither of these factors create a significant deviation from accuracy, except where talking about diseases specifically linked to sex chromosomes or mitochondria.So, the answer is that with respect to which DNA a child has: yes, they basically have 50% from each parent. There are many complicating factors, however, caused by traits having dominant and recessive alleles, and other traits being controlled by an enormous number of genes (such as skin colour).So children have 50% of each of their parents' DNA, but that doesn't translate into 50% of their traits. Which parent a child most resembles is basically down to chance, but their overall genetic make-up has an equivalent contribution from each parent. A child is no more likely to resemble their father than their mother.