Question:
Which of the following actions could prevent mass-movement disasters?(a)constructing building and roads in stream drainage paths
(b)removing trees from steep slopes
(c)educating people about the advantages of building on steep slopes
(d)digging a series of trenches to divert water around a slope
<u>Answer</u>:
"Digging a series of trenches to divert water around a slope" could prevent mass-movement disasters
<u>Explanation</u>:
The trenches are made of 12 to 15 inches in width and at least 6-8 inches depth, can help in normal drainage problem. But in long, steep slopes and areas receiving heavy rainfall, digging of trenches is more advisable. It prevents the tripping over and falling down of people, it protects the runoff of edges and also collapsing. These trenches should be filled with coarse gravel or may be small stones. In the final labelling one or two inch of fine gravel or coarse sand. It will make the surface level which will allow the water to seep down.
The male fruit fly has an XY profile of the sex chromosomes, and the female has an XX profile of the sex chromosomes.
If a male is white-eyed, then it must have a white recessive allele on his only X chromosome and the red eyed female can be homozygous (having two dominant red eye alleles) or heterozygous (having both a dominant and a recessive allele).
If the female is homozygous then all of the offspring will be red-eyed, and if she's heterozygous then half of the offspring will be white eyed. (see the table provided below)
The answer is A index fossils