A Quote by Kenneth R. Miller
Although each egg cell produced by a woman carries a single X chromosome, the sperm cells produced by a man carry either an X or a Y. This means, in very simple terms, that the sperm cell determines a baby's sex.
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The egg of every species of animal or plant carries a definite number of bodies called chromosomes. The sperm carries the same number. Consequently, when the sperm unites with the egg, the fertilized egg will contain the double number of chromosomes.
For each chromosome contributed by the sperm there is a corresponding chromosome contributed by the egg, there are two chromosomes of each kind, which together constitute a pair.
To date, embryonic stem cell research has not produced a single medical treatment, where ethical, adult stem cell research has produced some 67 medical miracles.
The cloning procedure is similar to IVF. The only difference is that the DNA of sperm and egg would be replaced by DNA from an adult cell. What law or principle - secular, humanist, or religious - says that one combination of genetic material in a flask is OK, but another is not?
It is not a simple life to be a single cell, although I have no right to say so, having been a single cell so long ago myself that I have no memory at all of that stage of my life.
It is a well-documented fact that guys will not ask for directions. This is a biological thing. This is why it takes several million sperm cells... to locate a female egg, despite the fact that the egg is, relative to them, the size of Wisconsin.
The number of cells in our bodies is defined by an equilibrium of opposing forces: mitosis adds cells, while programmed cell death removes them. Just as too much cell division can lead to a pathological increase in cell number, so can too little cell death.
A stem cell is essentially a blank cell capable of becoming another, more differentiated cell-type in the body, such as a skin cell, a muscle cell or a nerve cell.
Man comes not from an egg but from an animalcule that is found in male sperm.
Each individual is a cosmos of organs, each organ is a cosmos of cells, each cell is a cosmos of infinitely small ones; and in this complex world, the well-being of the whole depends entirely on the sum of well-being enjoyed by each of the least microscopic particles of organized matter. A whole revolution is thus produced in the philosophy of life.
Every batch of sperm represents an opportunity for genetic typos - called de novo mutations - to be passed on. A 20-year-old man and woman will each pass on about 20 de novo mutations to a baby they conceive. By the time the couple is 40, a woman's total has remained at 20, while a man's has jumped to 65 - and it keeps climbing from there.
Women of child-bearing age steadily run out of eggs by the continuous process of cell death. While reading a copy of the 'Guardian' carefully from cover to cover, a normal woman will have lost on average two eggs - while, typically, a normal man will have made 70,000 new sperm.
Women of child-bearing age steadily run out of eggs by the continuous process of cell death. While reading a copy of the Guardian carefully from cover to cover, a normal woman will have lost on average two eggs - while, typically, a normal man will have made 70,000 new sperm.
There is a duality in recognising what an incredible disease it is - in terms of its origin, that it emerges out of a normal cell. It's a reminder of what a wonderful thing a normal cell is. In a very cold, scientific sense, I think a cancer cell is a kind of biological marvel.
An irrefutable proof that such single-celled primaeval animals really existed as the direct ancestors of Man, is furnished according to the fundamental law of biogeny by the fact that the human egg is nothing more than a simple cell.
Upon the union of the male germ cell with the female egg cell, a new cell is created which almost immediately splits into two parts. One of these grows rapidly, creating the human body of the individual with all its organs, and dies only with the individual.
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