Answer:
The correct option is A. Coal use in steam engines led to easier access to goods.
Explanation:
Coal is used in steam engines as a fuel. Coal is one of the cheapest source of energy and hence it has been serving mankind with various benefits since a long period of time.
The coal-based steam engines played a very important role in the developments made during the Industrial Revolution. Many industries started using coal as a power material and made progress.
The steam engines made it possible to transfer goods from one place to another very easily. As coal was a cheap source, hence trading of goods by steam engines was not very costly.
Answer:
A.
Explanation:
Because the trait undergoes a secondary loss; it has been there but it doesn't always appear in all generations.
The art of breathing in someway.
Answer:
Genotype ratio: 1, 1:1, 1:2:1
Phenotype ratio: 1, 3:1
Explanation:
Single gene pair cross is also known as monohybrid cross. This means that only one gene usually with two alleles is observed and it express one trait.
For example, if we name the gene for a certain trait with A, the possible genotypes are AA (dominant homozygous), aa (recessive homozygous) and Aa (heterozygous). Possible crosses are:
P: AA x AA
F1 : all of them are AA
The same is with aa x aa (all of the offspring are with aa genotype)
P: AA x Aa
F1: AA Aa AA Aa (genotype ratio 1:1) (phenotype ratio 3:1)
The same genotype ratio is in aa x Aa (offspring will have aa Aa aa Aa-(genotype ratio 1:1) (phenotype ratio 1:1)
P: Aa x Aa
F1: AA Aa Aa aa (genotype ratio 1:2:1) (phenotype ratio 3:1)
P: AA x aa
F1: Aa Aa Aa Aa (1)