What is the difference between test tube cloning and test tube fertilization?

Answer 1

First, the term "test tube" is popular, but it is not the terminology used by scientists. They instead use the latin term 'in vitro' (literal definition: in glass; but modern definition more like 'outside the organism'; the opposite is 'in vivo'),

In vitro fertilization is simply putting sperm and egg together outside the body (and it's generally done in a dish, not a test tube!).

Cloning comes in two different forms: Reproductive Cloning and therapeutic cloning.

Reproductive cloning is the making of copy of an organism. It can be done in different ways. A natural form of cloning is to simply split an early embryo into two. At very early stages - say when the embryo is only a couple dozen cells, splitting it in half will result in the development of two genetically identical individuals. When this happens in nature, we call the offspring 'identical twins'.

Reproductive cloning can also be done by injecting the DNA from one organism into an embyronic stem cell of another, and then letting that cell divide and develop into an embryo and eventually an organism.

Therapeutic cloning is a completely different thing - When scientists talk about cloning - they are almost always talking about therapeutic cloning. Therapeutic cloning is the making of a copy of a single gene, or at it's most advanced, the copying of an entire strand of DNA. This is not used to produce another organism, but rather, to make copies of genes that can be altered and then engineered back into an animals genome.

For example, there might be a gene that confers a certain disease resistance, then can be cloned, and then spliced into the genome of a crop plant so that the plant is now disease-resistant.

Test tube cloning is altering the embryo. Test tube fertilization is when they take a sperm and egg and join them outside of the body. Then after fertilization it is placed back into the mother.