Identical twins have exactly the same genes. Identical twins result when
In peas, the gene for green color is dominant over the gene for yellow color. We will specify the gene for yellow peas as y, and the gene for green peas as Y. Each pea has two genes for color (one from each parent) and donates only one gene for color to its offspring. Yellow peas have the genotype yy. Any other genotype leads to green peas. Consider the following Punnett square:The offspring of these two parents
Which of the following is NOT true?
In humans, a pair of chromosomes (one from each parent) determines the sex of the baby. Females have two X chromosomes, while males have an X and a Y chromosome. The baby always gets an X chromosome from the mother, so in humans, the father determines the sex of the baby by supplying it with either an X chromosome to make it female, or a Y chromosome to make it male. In birds, like in humans, a pair of chromosomes determines the sex. Birds with two W chromosomes are male. Birds with a W chromosome and a Z chromosome are female. Which statement is true about birds?
A species may live in association with another species. Such an arrangement is called symbiosis. Symbiosis in which both species benefit is called mutualism. If the symbiosis is beneficial to one species and neither beneficial nor harmful to the other, it is called commensalism. If one species benefits at the expense of the other, the relationship is called parasitism. A tick that attaches to the skin of a human or animal and feeds on its blood is an example of
In an acid base reaction, an acid reacts with a base to produce water and a salt. The pH scale can be used to describe the acidity of a liquid. Look at the diagram below. Which two liquids could undergo an acid base reaction?
