AP PSYCHOLOGY

Detailed explanation-1: -Two separate eggs (ova) are fertilised by two separate sperm, resulting in fraternal or ‘dizygotic’ (two-cell) twins. These babies will be no more alike than siblings born at separate times. The babies can be either the same sex or different sexes, with the odds roughly equal for each.

Detailed explanation-2: -Unlike identical twins-who are genetically the same-fraternal twins are no more closely related in terms of DNA than regular siblings. But scientists often like to compare identical and fraternal twins to understand how much variation in a trait is due to environment versus genetics.

Detailed explanation-3: -Just like other siblings, fraternal twins will share about 50% of their DNA. 13 Each person receives half of their DNA from their mother’s egg and the other half from their father’s sperm, so any two offspring will have some overlapping qualities.

Detailed explanation-4: -Twins can be either monozygotic (’identical’), meaning that they develop from one zygote, which splits and forms two embryos, or dizygotic (’fraternal’), meaning that each twin develops from a separate egg and each egg is fertilized by its own sperm cell.

Detailed explanation-5: -Fraternal twins or non-identical twins are known as dizygotic. These twins are the result of two separate eggs, fertilised by two separate sperms. As such, these siblings are no more alike than siblings from different births, and may be both male, both female, or one male and one female.