Problem 9 - Biology

Question

A photomicrograph of the stained metaphase chromosomes present in a given cell is called a (a) karyotype (b) nucleotide triplet repeat (c) pedigree (d) DNA microarray (e) translocation

Step-by-Step Solution

Answer

(a) karyotype

Step 1: Understand the Question

The question asks us to identify what a photomicrograph of stained metaphase chromosomes is called, from a list of given options.

Step 2: Analyze Each Option

Go through each option: - (a) Karyotype refers to the number and appearance of chromosomes in the cell nucleus and involves a photograph taken to visualize these chromosomes. - (b) Nucleotide triplet repeat is a sequence of three nucleotides repeated multiple times but does not refer to any photographic process. - (c) Pedigree is a diagram showing the lineage or genealogy of an individual and is unrelated to chromosomes directly. - (d) DNA microarray is a tool used to detect the expression of thousands of genes at once. - (e) Translocation is a chromosomal abnormality where a chromosome breaks and a portion of it reattaches to a different chromosome.

Step 3: Select the Correct Answer

Based on the analysis of the options, option (a) Karyotype is the term for a photomicrograph of stained metaphase chromosomes. It is the process used to visualize and study the chromosome composition of an individual.

Key Concepts

Metaphase Chromosomes

When we speak about metaphase chromosomes, we are referring to chromosomes at a specific stage during cell division known as metaphase. During this phase, chromosomes are most visible and condensed, making them ideal for viewing.
This is why scientists often photograph chromosomes during metaphase.
At metaphase, chromosomes align themselves along the center or equatorial plane of the cell.

• This highly organized chromosome arrangement allows for easy observation and comparison.
• It ensures that each daughter cell will receive an identical set of chromosomes.
• This phase allows for the clear separation of genetic material during the following stages of cell division.

Because metaphase chromosomes are so well-organized and visible, they are often used for studying chromosome structure, number, and any possible abnormalities such as extra chromosomes or structural defects.

Chromosome Imaging

Chromosome imaging is a crucial technique used in genetics to visualize the chromosomes of a cell. Imaging techniques usually involve capturing photographs, known as karyotypes, of chromosomes during metaphase.
These images provide detailed insight into the genetic blueprint of an organism.

• The process begins with staining chromosomes to enhance visibility.
• Special dyes bind to chromosome regions, highlighting bands or distinctive patterns.
• These patterns help differentiate between chromosomes.

Chromosome imaging lays the foundational groundwork for various genetic analyses.
It enables the detection of chromosomal abnormalities such as deletions, duplications, and translocations that can lead to genetic disorders.

Chromosomal Analysis

The analysis of chromosomes, or chromosomal analysis, is a sophisticated process that allows scientists to examine the number and structure of chromosomes. This is crucial for identifying genetic conditions and abnormalities. A karyotype is often used in this analysis to provide visual information about an organism's chromosomes.
Karyotyping involves:

• The arrangement of stained chromosomes in a systematic way.
• Comparison against normal chromosome patterns to identify deviations.
• Identifying the sex of an organism by examining the sex chromosomes (XX or XY).

Such analysis detects conditions like Down syndrome, where an extra copy of chromosome 21 is present.
It's invaluable for prenatal diagnosis, cancer studies, and understanding congenital disorders. By examining metaphase chromosomes through chromosome imaging, scientists can accurately perform chromosomal analysis and thus provide vital information on an individual's genetic health.