Pollen tube growth is one of the most fascinating—and essential—phenomena in the life cycle of flowering plants. After a compatible interaction between pollen grains and the stigma surface, the pollen germinates and forms the pollen tube, which grows through the stigma, style, and transmitting tract to deliver the sperm cells to the ovule."
2) Although pollens of many species germinate in simple aqueous media, stigmas do not provide satisfactory sites for the germination of most foreign pollen... Stigmas not only provide the proper conditions for the germination of pollen from their particular species, they actively inhibit the germination of pollen of many unrelated species.
Arabian plate and Eurasian plate is the correct answer.
Answer:
A,C,G,T
Explanation:
The DNA is a macromolecule formed by two strands of polynucleotides forming a double helix.
These chains are composed of monomers called nucleotides, there are 4 different types in DNA, called nitrogenous bases: two purines, guanine (G) and adenine (A) and two pyrimidines, thymine (T) and cytosine (C). They are joined by covalent bonds in each chain in a complementary way. G with C and A with T.
These are the chemicals Craig Venter has in the four bottles.
Answer:
Electric current is the flow of electrons and they carry negative charge so electrons inside an atom repels the flow where as a proton attracts the flow.
Explanation:
- Electricity is the process of flow of electrons. During the flow these electrons share bonds or even transfer them.
- These electrons get energy when the potential difference is applied to a conductor that is moving in the direction from low to high therefore, the electrons move from one to another creating electricity.
- Though the electron repels the continuous flow but proton develops the force of attraction.
