The karyotype of a normal human male would show a total of 23 pairs of homologous chromosomes.

Question

Answer the following statement true (T) or false (F)

Answer 1

False

Clarify Question

What is the key concept addressed by the question?
The question is asking about the chromosomes of a human male somatic cell. 
What type of thinking is required?
You are being asked to take what you already know about homologous chromosomes, the chromosome complement of humans, and human sex chromosomes, and to use these pieces of information to determine how many pairs of homologous chromosomes are found in a cell of a male. 
What key words does the question contain?
Karyotype, appearance and structure of the chromosomes of an organism 
Homologous chromosomes, matching pair of chromosomes in a diploid organism 

Gather Content

What do you already know about homologous chromosomes? About the chromosome complement of humans? What other information is related to the question?
When an organism is diploid (such as humans), the members of a pair of chromosomes are called homologs or homologous chromosomes. Homologous chromosomes are very similar to each other; a particular gene found on one homolog is found in a similar position on the other homolog (alleles can be different). 
Humans have 23 chromosomes in each set. In each set are 22 autosomes and one sex chromosome; sex chromosomes are designated X and Y. In females, the sex chromosome set includes two X chromosomes. In males, the sex chromosome set includes an X and a Y chromosome. 

Choose Answer

Given what you now know, what information is most likely to produce the correct answer?
A karyotype is a photographic representation of a cell's chromosomes. If you were looking at chromosomes from a male, you would see 22 pairs of homologous autosomes, and an X chromosome, and a Y chromosome. The question becomes then, whether the X and Y chromosomes are homologs. Although during meiosis, the X and Y will assort as if they are homologs, they are not homologs. They differ in size and genetic composition. Thus, the correct answer is false. 

Reflect on Process

Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
Answering the question depended on your ability to use what you already know about homologous chromosomes, the chromosome complement of humans, and human sex chromosomes and to use these pieces of information to determine how many pairs of homologous chromosomes are found in a cell of a male. 
If you got the correct answer, great! If not, remember it's important to use a systematic approach to answer questions and to reinforce those good habits over time. If you got an incorrect answer, where did the process break down? Did you remember that homologous chromosomes have the same genes in the same positions along the chromosomes (although they may have different alleles)? Did you remember that the X and Y chromosomes differ in size and genetic composition? Did you understand that the X and Y chromosomes are not considered homologs (although they do contain enough similarity to pair during meiosis)? Were you able to conclude that since the X and Y chromosomes are not homologs, there would be 22 (not 23) homologous pairs of chromosomes in a human male karyotype?