Answer:
Activated
Explanation:
In the presence of lactose, and in the absence of glucose, lactose will bind to a protein called a "repressor," deactivating it. Through this, RNA polymerase has a free way to synthesize the mRNA that will give enzymes for lactose degradation.
The wood in a matchstick is made of cellulose, a polymer of glucose molecules. When you light the matchstick, heat and light are given off, indicating that an exothermic reaction is occurring.
There are two types of reactions:
1. Exothermic reactions: In these reactions, the reactants combine to form product and heat is liberated. Example, burning of fuel.
2.Endothermic reactions: In these reactions, the reactants combine to form product and heat gets absorbed from the surroundings. Example, photosynthesis in plants where the energy of the Sun gets absorbed.
Temperature, and Humidity are the two important factors of an ecosystem
The answer;
A combination pill
Explanation;
Contraception entails methods that are used to prevent pregnancy. They include; hormonal methods, barrier methods and natural methods. A combination pill is a type of oral contraceptives that contain estrogen and a progestin. It keeps the ovaries of the female from releasing an egg. Different types of this pill contains different doses of estrogen and progestin.
Answer:
B
Explanation:
RNAi is a cellular mechanism for post-transcriptional gene silencing. After transcription of a gene into mRNA, small interfering RNA (siRNA) and microRNA (miRNA) can target the mRNA to form dsRNA. This mRNA then becomes a target of ribonucleases such as the Dicer that break it apart. These mRNA, therefore, do not reach the cytoplasm for translation by ribosomes. This mechanism is hence harnessed and manipulated by scientists to study genes by silencing them.
