I have 3 biology questions. need help please!

which of the following tools is used to match up chromosome pairs using chemical stains?
A) pedigree chart
B) karyotype
C) meiosis map
D) linkage map

In a genotype for plant height, such as Tt, what does each letter represent?
A) one genome
B) one gene
C) one allele
D) one gamete

Which law states that organisms inherit two copies of each gene and donate one copy to each of their offspring?
A) law of genetic linkage
B) law of segregation
C) law of independent assortment
D) law of inheritance

thanks!

1. b
2. c
3. d