DSWO WEEK 19 2019
DSWO WEEK 19
1-14 Life – Biology - compare/contrast
What is the difference between identical and fraternal twins?
1-15 Life – Psychology – hypothesizing
For the most part, the left half of the brain controls the right half of the body, and the right half of the brain controls the left half of the body. How do you think this connection was discovered?
1-16 Life – Biology- inferring
Which appeared first on earth, plants or animals? Give reasons for your answer.
1-17 Physical – Chemistry – hypothesizing
Imagine you’re preparing a fresh fruit salad for a party. How can you keep the apple and banana slices in the salad from turning brown?
1-14 Identical twins have the exact same genes. They develop from the same fertilized egg, which means they look identical and are the same sex. Fraternal twins come from 2 different eggs, so they do not necessarily look the same and may be of different sexes.
1-15 Psychologists and physicians have been able to examine persons who have suffered damage to specific parts of their brains. For instance, when a person has a blood clot in the brain, a part of the brain may stop functioning because of insufficient blood flow. This event is called a stroke. Many stroke victims lose the use of a hand or arm, or even an entire side of the body. Autopsies of stroke victims reveal damage to the side of the brain opposite the disabled part of the body.
1-16 A plant is the earliest form of life found thus far by scientists. In a remote part of western Australia, scientists have found what appear to be nearly the oldest known rocks on earth. These rocks are about 3.5 billion years old. They are called stromatolites and contain the fossilized remains of at least 5 different life forms. The fossils appear to have been formed by pond scum, which used carbon dioxide (as plants do today) and grew in tiny strands.
1-17 You can dip the slices in water, sprinkle them with lemon juice, or put them in an airtight container. These techniques prevent oxygen from reacting with the molecules in the fruit. When oxygen comes into contact with the exposed flesh of some fruits, a series of chemical reactions begins. These reactions create the brown pigment that covers the exposed part of the fruit. Water coats the surface of the fruit to prevent oxygen from reaching it for a while. The vitamin C in lemon juice bonds with the oxygen to prevent it from reacting with the molecules of the fruit. An airtight container prevents oxygen from reaching the fruit as well.