Eukaryotic cells have a membrane-bound nucleus, whereas prokaryotic cells do not. In eukaryotes, the nucleus is just one of numerous membrane-bound organelles. Prokaryotes, on the other hand, lack organelles that are attached to the membrane.
Answer:
3 Pollen tube forms and grows through the style
5 Sperm fertilizes the egg
1 Pollen is released from the anther
4 The pollen tube reaches the ovule within the ovary
2 Pollen sticks to the stigma
Explanation:
The process of double fertilization entails the fertilization of the egg by one sperm and that of two polar nuclei to produce the triploid endosperm tissue that nourishes embryo.
* The image describes the process in detail.
Answer:
The correct answer will be option-B (purine).
Explanation:
Nucleic acid structure is made up of monomer unit called nucleotide. Each nucleotide is composed of a five-carbon sugar, a phosphate group and five types of nitrogenous bases.
The nitrogenous bases are categorized in two forms the purines (adenine and guanine ) and the pyrimidines (cytosine, thymine and uracil). The "purines" contain double rings in their structure due to which they appear larger in size than pyrimidines which are made up of single rings.
Thus, Option-B is the correct answer.
Answer:
(A). mRNA.
Explanation:
During protein synthesis, information present in DNA as triplet codons gets transferred to mRNA molecule, by the process of transcription. The mRNA than gets transported to the cytosol, where it associates with ribosomes.
Ribosomes are known as protein factories of the cells as they provide platform for translation. During translation, information present in mRNA is used to translate polypeptide chain or protein as each codon codes for a specific amino acid.
Thus, the correct answer is option (A).
