Answer:
2.Biotic factors are dependent on abiotic factors for food and protection.
3.Abiotic factors affect the type and number of organisms that live in a particular ecosystem.
Explanation:
An ecosystem is an environment that contains both living and non-living parts that actively interacts together.
The living part of the ecosystem is the biotic factors and the non-living parts are the abiotic factors.
- The biotic components actively depends on the abiotic component for nourishment.
- This is exemplified through the process of photosynthesis.
- Also, the shelter of organisms are derived from the abiotic factors.
- The abiotic factors have significant impact on the type and number of organisms that live in an ecosystem.
Answer:
1. when new evidence proves it incorrect
2. theory
Answer:
tell teacher, dispose, first aid kit
Answer:
a. Acts as a repressor (inhibits transcription from the lac operon)
Explanation:
LacI is a repressor protein that plays an important role in lac operon. Lac operon is usually switched off i.e. it is inactive in absence of lactose and presence of glucose. The operon has an operator region, promoter region and structural genes.
In absence of lactose, LacI repressor binds to the operator area. Since operator region overlaps with the promoter region, RNA Polymerase is not able to bind to promoter due to presence of repressor. Transcription of lac operon genes does not take place. When lactose is present, some of it is converted into allolactose. Allolactose binds to LacI repressor making it change its shape. The repressor is no longer able to bind to operator region and RNA Polymerase is free to transcribe the genes making the operon active.
