Answer:
Explanation:the cranial end of the neural tube closes by 24days and the caudal 25-36 days . Defective closure of the neural tube result in neural tube defects (NTDs) . it also depends on the point of the defect , NTDs may also affect the brain and spinal cord.
LATitude are the lines that go around the world. They are like a LATter.
Longitude go from the north pole to the south pole.
Answer:
Karl von Frisch is best known for two major discoveries about honey bees. First, he demonstrated that honey bees have color vision, and published these findings in 191*. Second, in 193* he showed that honey bees use a dance language to communicate food locations to other bees.
Explanation:
Figure 1. Grids for the color vision test. The training color, marked with T, is blue in both cases; all other squares are shades of gray. The left box shows how the grid appears to an animal with color vision. The right box shows how the same grid may appear to an animal without color vision. The training square appears to be the same shade of gray as other squares in the grid. If the test animal cannot see in color, it will confuse the training square with other squares matching its shade of gray.
This clever test for color vision can be applied to any animal which can learn to recognize a feeding station using visual patterns.
The dance language
von Frisch observed that once one honey bee finds a feeding station, many other soon appear at the same station. This suggests that the first bee recruits other bees to the food. How might honey bees recruit help in collecting food? von Frisch¹s discovery of the dance language of the honey bee required careful determination of the correlations between movements of bees inside the hive and the locations of feeding stations. He found two types of dance. The round dance (Figure 2A) causes bees to look for food a short distance (up to about 50 meters) from the hive. The waggle dance (Figure 2B) tells bees the direction and distance to fly to find more distant food sources. Scout bees use these dances to recruit assistance in collecting food resources.
