Read the sentences.
the arctic region, where winters are long and cold, is home to more than 400 species of flowering plants.
which group of words is an adjective clause in the sentence?

of flowering plants

is home to more than 400 species of flowering plants

the arctic region, where winters are long and cold

where winters are long and cold

The answer to your question would be that the group of words that is an adjective clause in the sentence is the following one: Where winters are long and cold.

Explanation:

It is a nonessential adjective clause, which is also called relative clause.  This means that the information it provides is not relevant to identify the noun it modifies or to complete the meaning of the sentence. Consequently, it could be dropped without altering the meaning of the sentence (see 1). That is why it is offset with commas from the main sentence.

1) The Arctic region is home to more than 400 species of flowering plants

whoy te be di hew jal

explanation:

elon musk, ceo of spacex, a startup space company is planning to head to mars by 2023. nasa is planning to go to mars at around 2025. both are just for a basic colony.