Chapter 21, Problem 1SQ

Multicelled haploid and diploid bodies form in protists that have a(n) __________.

1. a. haploid-dominant life cycle
2. b. diploid-dominant life cycle
3. c. c alternation of generations

Summary Introduction

Concept introduction: Protists are a diverse taxonomic group of eukaryotic organisms that are unicellular, sometimes colonial, or less often, multi-cellular; it includes protozoans, most algae, and often some fungi. Some protists have a cycle dominated by haploid forms and some protists have a cycle dominated by diploid forms.

Answer to Problem 1SQ

Correct answer: Multi-celled haploid and diploid bodies form in protists that have an alternation of generations. Therefore, option c. is correct.

Explanation of Solution

Reason for the correct statement:

Protists reproduce asexually when the conditions favor their growth. They switch to sexual reproduction when they do not. Multi-cellular algae and all plants have an alternation of generations. In the alternation of generations, both haploid and diploid bodies will form.

Option c. is given as “alternation of generations”. As the multi-celled haploid and diploid bodies form in protists, they have an alternation of generations. Hence, option c. is the correct answer.

Reasons for the incorrect statements:

Option a. is given as “haploid-dominant life cycle”.

Multi-celled haploid and diploid bodies formed in protists do not have a haploid-dominant life cycle. Therefore, option a. is incorrect.

Option b. is given as “diploid-dominant life cycle”.

Multi-celled haploid and diploid bodies formed in protists do not have a diploid-dominant life cycle. Therefore, option b. is correct.

Hence, options a. and b. are incorrect.

Conclusion

Multi-cellular haploid and diploid bodies in protists have an alternation of generations.