Problem 3 - Biology Concepts and Applications

Question

3\. A somatic cell having two of each type of chromosome has a(n) ____________ chromosome number. a. diploid b. haploid c. tetraploid d. abnormal

Step-by-Step Solution

Answer

The answer is a. diploid.

Step 1: Understanding Chromosome Number Terms

A somatic cell refers to any cell forming the body of an organism, excluding gametes. The term 'chromosome number' can be described in various forms: 'diploid', 'haploid', 'tetraploid', and 'abnormal'. These refer to the number of sets of chromosomes a cell contains.

Step 2: Define and Comprehend Diploid and Haploid

In biology, 'diploid' refers to a cell that contains two complete sets of chromosomes (one from each parent), denoted as 2n. On the other hand, 'haploid' refers to the single set of chromosomes or n, which is typical of gametes (sperm and egg cells).

Step 3: Apply Definitions to the Exercise

Since the question mentions a somatic cell having "two of each type of chromosome", this matches the definition of a diploid cell, as diploid cells contain two sets of chromosomes.

Key Concepts

Chromosome Number

Chromosome number refers to the total count of chromosomes present in the nucleus of a cell. It is a fundamental characteristic that varies among different species. In humans, the typical chromosome number is 46. This count includes 23 pairs of chromosomes, with one set inherited from each parent. Each pair consists of homologous chromosomes, meaning they contain the same genes but may have different alleles (variations of the same gene).

Chromosome numbers are categorized into terms like diploid, haploid, and sometimes, more complex arrangements like tetraploid. Knowing the chromosome number helps in understanding an organism's cellular structure and its genetic blueprint.

• In diploid cells (denoted as 2n), the chromosome number represents pairs, making them crucial in growth and development.
• Haploid cells (n) have half the chromosome number and are important for sexual reproduction.

Somatic Cell

Somatic cells make up most of the body's tissues and organs, playing a vital role in growth, development, and repair. These are any cells forming the body that are not involved in reproduction.

A defining feature of somatic cells is that they are diploid, meaning they contain two sets of chromosomes (2n), with one set inherited from each parent. For humans, this sums up to 46 chromosomes in total. This diploid nature allows somatic cells to divide and maintain genetic consistency through the process called mitosis.

• Somatic cells help in forming various body parts like skin, muscles, and bones.
• They differ from gametes (sperm and egg cells), which are involved in reproduction and have a haploid chromosome number.

Haploid

Haploid refers to a cell that possesses a single set of chromosomes (n). These cells are crucial in the context of sexual reproduction. In humans, haploid cells have 23 chromosomes, which are unpaired.

The primary examples of haploid cells are gametes: sperm cells in males and egg cells in females. During fertilization, these haploid cells combine to form a diploid cell, restoring the typical chromosome count of the species. This process ensures genetic diversity and the continuation of a species.

• Haploid cells are produced through a special type of cell division called meiosis.
• They are vital for maintaining genetic variety across generations.