Tutor profile: Alex L.
Why are the noble gasses called "noble gasses"?
An atom of any of the noble gasses is unlikely to react with other atoms to form compounds. The last layer of electrons in their electron shell is full, therefore they are unlikely to either lose or gain an electron.
In Mendelian genetics, what is the probability that the offspring of two heterozygous parents will display the recessive phenotype?
25%. Each parent is heterozygous, which means each parent carries one dominant gene and one recessive gene. Here's an example: Parent 1 genotype: Dd Parent 2 genotype: Dd An offspring will inherit one gene from each parent. From each parent, an offspring has a 50% chance of inheriting the D gene and a 50% chance of inheriting the d gene. Potential offspring genotypes: DD, Dd, Dd, dd The phenotype is determined based on whether the dominant gene is present. Three of the 4 possible offspring genotypes contain at least 1 of the dominant genes (D). Therefore there is a 75% chance (3/4) that an offspring will display the dominant phenotype, and a 25% chance (1/4) that an offspring will display the recessive phenotype.
Solve the following equation for $$x$$: $$ 3x = 4x + 2 $$
Isolate the variable by subtracting $$4x$$ from both sides. $$ 3x - 4x = 4x + 2 - 4x $$ $$ (3-4)x = (4-4)x +2 $$ $$ -x = 2$$ Then multiply both sides by $$-1$$. $$ (-1)(-x) = (-1)(2)$$ $$ x = -2$$