Euglena are a unicellular organism. They are classified into the Kingdom Protista. They are then further classified into the Phylum<span> Euglenophyta. All euglena can make their own food by photosynthesis.</span>
Answer:
Secondary consumers.
Explanation:
In a trophic pyramid, there are conventionally four levels. From the bottom they are: Producers, Primary Consumers: Secondary Consumers, and at the top we have tertiary consumers. Each level generally consumes animals in the level below it. Producers consist of plants.
The controlled experiments are performed by the scientists, when they want to study the changes in the sample on changing a single variable. So, the correct answer is option (b).
In case, all variables are kept same, no changes would be observed in the experiment sample. A controlled experiment can be performed on living thing as well as non living. But, controlled experiment cannot be performed on the things which are influenced by a lot of variables, as they cannot create realistic results. So, the option (a), (c), and (d) are incorrect.
Answer:
Competition.
Explanation:
The interaction between the organisms can be beneficial harmful or neutral depending on the types of organisms. Different types of interaction are mutualism, ammensalism and commensalism.
The competition occurs when the individual compete for the same resources or for the habitat. The competition results in the exclusion of one species and determines the distribution of other species.
Thus, the answer is competition.