Showing posts with label genetics. Show all posts
Showing posts with label genetics. Show all posts

Thursday, September 29, 2011

Seeing Double



In July 1996, it was announced that a sheep had been been born at the Roslin Insitute near Edinburgh, Scotland. What was so amazing about this? Dolly was the first clone. She was very famous. A sweater knitted from her wool was placed in a museum. She had several sheep of her own, none of them clones and all healthy. Everyone talked about how humans would be next. But what is cloning, really?

Cloning comes from the Latin root meaning "to cut from". A clone is an organism grown from a single cell of the parent, genetically identical to the parent. To clone Dolly, they took the nucleus from a sheep egg and replaced it with the nucleus from a sheep cell. A little chemical manipulation and "Hello, Dolly". Cloning creates nothing new, it just makes a copy, like having an identical twin.

What happened to Dolly? At three, she showed signs of premature aging, and she passed away at age six - a young age for a sheep. "Goodbye, Dolly" didn't make the news a lot. But why did she die? Because of the cell that was put into the egg. The DNA was six years old when she was born. The egg that was used to produce her came from a six year old sheep, which made her genes six years old when she was born, meaning she aged faster and died a horrible death. Every cloned animal has died a horrible death.

We did not invent cloning. God did. If you've ever grown strawberries, you'll know that runners come off the plants, new plants for next year. These runners are actually clones of the plant. Some types of female insects produce eggs that, when hatched, produce clones of themselves.

Is cloning immoral? For my part, I have no problem with the idea of cloning plants and animals, if our intentions in doing so are right, such as attempting to cure a disease. We were granted dominion over them, and although we shouldn't abuse it, we can do many positive things through cloning plants and animals. We were not, however, given dominion over other humans. Think about it. God said we must not kill other people, but we were told it is alright to kill and eat animals. And furthermore, humans were meant to have two parents (although this is not always the case), but a cloned human could never. This goes directly against the Bible.

Thursday, September 22, 2011

DNA

DNA is short for deoxyribonucleic acid. DNA is what carries the instructions God put into us for what we look like and how our bodies work. Every species of organism has it, except for bacteria. Birds are born with DNA that makes them able to fly. We humans are all different. Some of us are tall, some of us have brown eyes, some of us have curly hair. But humans are generally not born with feathers.

A chromosome is a long strand of DNA wrapped around proteins. A gene is a length of DNA. Our genes are arranged along the chromosome like beads. Each chromosome has many genes. Within a species, a gene for a certain characteristic, such as black hair or blue eyes, is always on the same place on the same chromosome.

Each cell has two copies of each gene, one from each parent. These two same genes are called alleles. The combination of alleles is what makes each individual unique. The number of possible combinations is practically countless, with the thousands of genes in a chromosome.

A cell duplicates its chromosomes, its DNA, before it divides. A DNA is not a single molecule but is, instead, a double one. This gives it the ability to divide and reproduce. DNA is like a twisted zipper, with the bases the interlocking teeth of the zipper.

When DNA is duplicated, the two strands of DNA separate. The zipper unfastens. Enzymes, special proteins that control the speed of chemical reactions in the cell, bring nucleotides, small subunits on the chains of DNA, to the two DNA strands. The nucleotides link up with exposed bases and join together to form new strands attached to the originals. The result is two double strands.