Question

In the moss Polytrichum commune, the haploid chromosome number is 7. A haploid male gamete fuses with a haploid female gamete to form a diploid cell that divides and develops into the multicellular sporophyte. Cells of the sporophyte then undergo meiosis to produce haploid cells called spores. What is the probability that an individual spore will contain a set of chromosomes all of which came from the male gamete? Assume no recombination.

Answer 1

Answer:

1/128

Explanation:

In a diploid individual, 2ⁿ possible gametes can be produced, where n is the haploid chromosome number.

From those possible gametes,

• $(\frac{1}{2})^n$ is the number of gametes that will contain maternal chromosomes only

• $(\frac{1}{2})^n$ is the number of gametes that will contain paternal chromosomes only

• $1-2(\frac{1}{2})^n$ is the number of gametes that will contain a combination of both maternal and paternal chromosomes.

The probability that an individual spore will contain a set of chromosomes all of which came from the male gamete will be:

$(\frac{1}{2})^7=\frac{1}{128}$