第1个回答 2010-11-13
DNA(Deoxyribonucleic acid)，中文译名为脱氧核糖核酸，是染色体的主要化学成分，同时也是基因组成的，有时被称为“遗传微粒”。DNA是一种分子，可组成遗传指令，以引导生物发育与生命机能运作。主要功能是长期性的资讯储存，可比喻为“蓝图”或“食谱”。其中包含的指令，是建构细胞内其他的化合物，如蛋白质与RNA所需。带有遗传讯息的DNA片段称为基因，其他的DNA序列，有些直接以自身构造发挥作用，有些则参与调控遗传讯息的表现。
第2个回答 2010-11-13
Have you ever heard a news reporter talk about DNA? Reporters talk about DNA found at the scene of a crime. They talk about police finding DNA “fingerprints.” Police sometimes use DNA as a clue to find out who committed the crime.df
WHAT IS DNA?
DNA is a substance that makes up genes. Everything alive has genes. Plants have genes. Animals have genes. You have genes.
Genes are the basic units of heredity. Heredity means all the characteristics you inherit from your parents. You get your genes from your parents. You inherit half of your genes from your mother. You inherit half of your genes from your father.
Genes are a kind of code. A tree’s genes tell what shape its leaves will be. A cat’s genes tell what color its fur will be. Your genes tell what color your eyes will be. Your genes tell what color your hair will be. Everything about you comes from the code in your genes.
WHERE ARE GENES?
Genes line up on strands called chromosomes in cells. Everything alive is made up of cells. Chromosomes are in the center, or nucleus, of cells.
Different parts of you are made of different kinds of cells. Your muscles are made of muscle cells. Your skin is made of skin cells. The code in your genes tells your body to make different kinds of cells. The genes in each cell tell the cell how to work. They tell the cell when to make new copies of itself.
WHO DISCOVERED GENES?
An Austrian monk named Gregor Mendel first saw inherited patterns in pea plants. He experimented with pea plants in the 1860s. One of the things, or traits, Mendel studied was what makes some pea plants tall and some short. He said that the traits must come from units of heredity passed from the parent plants. These units were later called genes.
In the mid-1900s, scientists discovered that genes are made of DNA. In the 1970s, scientists learned how to change DNA with genetic engineering. Scientists also learned that problems with certain genes cause diseases. Muscular dystrophy, cystic fibrosis, and hemophilia are some genetic diseases—diseases caused by problems in genes. Today, scientists are looking for ways to cure genetic diseases by altering genes through a process called gene therapy.
第3个回答 2010-11-13
DNA is the main constituents of chromosomes, but also genes, sometimes referred to as "hereditary particles". DNA is a molecule made up of genetic instructions, to guide the biological development of life functioning. The main feature is the long-term information storage that can be likened to the "blueprint" or "recipes". The directive, is the construction of the cells of other compounds such as proteins and RNA. With the genetic information of DNA called genes, other DNA sequences, some direct role to play by its own structure, some are involved in the regulation of genetic messages.本回答被提问者采纳