Chapter 1: Problem 6

What is a gene?

Short Answer

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Answer: A gene is a segment of DNA that contains information needed to produce a specific molecule, usually a protein, crucial for the structure and function of cells and the organism. Genes are located on chromosomes and are responsible for specific traits through the process of inheritance. Gene expression, regulated by various factors, ensures correct proteins are produced in the appropriate cells and at the right times. Genetic variation between individuals can result in differences in traits or genetic disorders.

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Definition

A gene is a segment of DNA (deoxyribonucleic acid) that contains the information needed to produce a specific molecule, usually a protein, that plays a crucial role in the structure and function of cells and the organism as a whole.

DNA Structure

DNA is composed of two long chains of nucleotides, which are twisted together into a double helix. Each nucleotide is made up of a sugar, a phosphate, and a base (adenine, thymine, guanine, or cytosine). The order of these bases, known as the DNA sequence, determines which protein is produced by a particular gene.

Genes and Chromosomes

Genes are located on structures called chromosomes, which are found in the nucleus of each cell. Each chromosome contains hundreds to thousands of genes, and humans typically have 46 chromosomes (23 pairs) with around 20,000 to 25,000 genes in total.

Gene Expression

Not all genes are active (or "expressed") in every cell. Gene expression is the process by which the information stored in a gene is converted into a functional product, typically a protein. This process is regulated by various factors, such as cellular signals, environmental conditions, and developmental stages, to ensure that the correct proteins are produced in the right cells at the appropriate times.

Genetic Variation

Genetic variation is the existence of differences in DNA sequences between individuals within a population. This variation can be caused by mutations, which are changes in DNA sequences that can be passed down from one generation to another. Some genetic variations have no effect on an organism, while others can lead to genetic disorders or give rise to differences in traits, such as eye color or height.

Genes and Inheritance

The information in genes is passed down from one generation to another through the process of inheritance. Each individual receives one copy of every gene from their mother and one copy from their father. These copies, called alleles, can differ slightly in their DNA sequences, resulting in different versions of the same trait, such as blue or brown eyes.

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What is a gene?

Short Answer

Step by step solution

Definition

DNA Structure

Genes and Chromosomes

Gene Expression

Genetic Variation

Genes and Inheritance

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