(Q).
Answer the following question given this paragraph: It is believed that large mutations form new genes. Mutations that duplicate large sections of DNA are a major source of genetic material for new genes. It is thought that tens to hundreds of genes are duplicated in animal genomes every million years. Most genes belong to larger families of genes of shared ancestry. These gene families have domains within the protein with a particular and independent function. These domains have corresponding conserved regions within their genes. It is through duplication mutations that such gene families formed. Genetic recombination after duplication of different domains forms new combinations of domains with new functions. For example, the human eye uses four genes to make structures that sense light: three for color vision and one for night vision; all four arose from a single ancestral gene. Q: What is essential for forming new genes? Choices: - enough mutations - enough chromosomes - chromosome deversity - large mutations A:
(A).
large mutations

(Q).
Answer the following question given this paragraph: Citric acid is a large carboxylic acid with three ionizable hydrogen atoms. It is found in citrus fruits and gives them their sour or tart flavor. Q: What large carboxylic acid with three ionizable hydrogen atoms gives some fruits a sour or tart flavor? Choices: - ammonia acid - beryllium acid - hydrochloric acid - citric acid A:
(A).
citric acid

(Q).
Answer the following question given this paragraph: The nucleus is a membrane-enclosed organelle found in most eukaryotic cells. The nucleus is the largest organelle in the cell and contains most of the cell's genetic information (mitochondria also contain DNA, called mitochondrial DNA, but it makes up just a small percentage of the cell's overall DNA content). The genetic information, which contains the information for the structure and function of the organism, is found encoded in DNA in the form of genes. A gene is a short segment of DNA that contains information to encode an RNA molecule or a protein strand. DNA in the nucleus is organized in long linear strands that are attached to different proteins. These proteins help the DNA to coil up for better storage in the nucleus. Think how a string gets tightly coiled up if you twist one end while holding the other end. These long strands of coiled-up DNA and proteins are called chromosomes. Each chromosome contains many genes. Humans have about 20,000 to 22,000 genes scattered among 23 chromosomes. Q: Humans have about 20,000 to 22,000 genes scattered among 23 of these? Choices: - neutrons - ribosomes - atoms - chromosomes A:
(A).
chromosomes