Answer:
I want to say it is the middle layer. But not 100% sure. Sorry if its wrong.
Answer:
Weathering describes the breaking down or dissolving of rocks and minerals on the surface of the Earth. Water, ice, acids, salts, plants, animals, and changes in temperature are all agents of weathering.
One hypothesis that explains the result is : A) Two genes are involved with 12:3:1 epistasis, such that A_B_ and A_bb are black, aaB_ is brown,and aabb is green.
Explanation:
- This is a case of Dominant Epistasis.
- When two genes are involved and presence of dominant allele of one gene masks the effect of either allele of the second gene then the epistasis is termed as dominant epistasis.
- In the given case black :brown: green ratio is approximately equal to 12:3:1.
- Here presence of a dominant A allele that is responsible for the black colour masks the effect of either allele of B. Therefore A_B_ and A_bb produces black beetles
- Again , absence of dominant A allows B to express itself and Brown beetles are produced thus aaB_ is brown.
- When both the genes are present as recessive alleles, neither brown nor black colour is expressed and the beetles are green.Thus, aabb are green.
After two half-lives or 60 years, 7.5 g of the element will be left.
<u>Explanation:</u>
<u>Half-life:</u>
- In simple words, Half-life can be defined as the amount of time needed for a quantity to fall to half its value as contained at the beginning of the time period.
- In this problem the half-life of the element is thirty years, then after thirty years half of the sample would have decayed and half would be left as it is.
- After thirty years (The first half-life ) 30 /2 = 15 g declines and 15 g remains disappeared.
- And after another sixty years (The two half-lives) 15 /2 = 7.5 g declines and 7.5 g remains disappeared.
- After two half-lives or 60 years, 7.5 g of the element will be left.
Answer is A
Firstly axon must reach the threshold level and then depolarisation occurs. Depolarisation phrase means sodium enters and potassium leaves the axon . Choice C can't be because main idea is the entering of sodium ions.
