Question

In the five-kingdom classification, Chlamydomonas and Chlorella have been included in
A.Algae
B.Plantae
C.Monera
D.Protista

Answer 1

Whittaker gave the five-kingdom classification based on criteria including morphology, nutrition, and reproduction.

Complete step by step answer: Whittaker(1969) is an American taxonomist. He is known for his five kingdom classification. This system separated unicellular eukaryotes into kingdom Protista and does not consider viruses for classification.
Viruses are not included in this classification. The main criteria for classification used are as follows:
1. Cell structure
2. Thallus organization
3. Mode of nutrition
4. Reproduction
5. Phylogenetic relationship
Five kingdoms are-
Monera- It includes all the microorganisms with prokaryotic cells that lack a nuclear membrane, plastids, mitochondria, and advanced flagella.
Protista- These are generally single-celled eukaryotes such as Euglena and Amoeba , nutrition by photosynthesis, absorption, ingestion, and combination of these.
Plantae- Members of this kingdom are eukaryotic mostly multicellular autotrophs, with cellulose walls. The chloroplast is present and the nutritive mode is photosynthetic.
Fungi: It includes eukaryotic multicellular heterotrophs with the absorptive mode of nutrition.
Animalia- It includes multicellular heterotrophs with wall-less eukaryotic cells lacking plastids and photosynthetic pigments with the ingestive mode of nutrition.
This system has put together organisms which in earlier classification, were placed in different kingdoms. This system separated unicellular eukaryotes into the kingdom Protista. Kingdom Protista has brought together Chlamydomonas , Chlorella (earlier placed in Algae) with Paramoecium and Amoeba.
So, the correct answer is option D. Protista.

Note: Fungi is in a different kingdom because of differences in the cell wall structure and nutrition with respect to plants. Animal and plant kingdom is more homogenous than two-kingdom classification. It shows phylogenetic relationships even amongst the primitive forms.