Answer:
Angiosperms have seeds with an 3n endosperm due to double fertilization.
Explanation:
- Double fertilization is found only in flowering plants.
- In angiosperms, the female gametophyte does not grow after reaching eight nucleate stage.
- After fertilization and triple fusion, the zygote and primary endosperm are created and further growth of embryo sac continues.
- Triple fusion is the fusion of two haploid polar nuclei of female gametophyte and one male nuclei. This results in a 3n nucleus.
- The developing embryo obtains nutrition from the endosperm.
- If fertilization fails no endosperm is formed.
Answer: blood vessels or oxygen H2o 6^
Explanation:
<span>
Canis familiaris is the closest relative of Canis lupus. </span>
The words needed to fill the spaces and to complete the statement above are trees, grass, soil, and shrubs, respectively. In terms of biology, a succession is a process of evolving the structure of a biological population over time, who has two types- primary and secondary.
Answer:
The correct answer is <em>A. real-time PCR can measure the amount of DNA amplified as the reaction proceeds, while standard PCR cannot.</em>
Explanation:
PCR (Polymerase Chain Reaction) is a molecular biology technique. Conventional PCR and real-time PCR are diferent types of PCR, and are both used to exponentially amplify DNA molecules. In both types, a polimerase enzyme is employed to sinthesize DNA copies. The main difference is that conventional PCR is qualitative whereas real-time PCR is quantitative. So, real-time PCR permits not only to detect and amplify DNA but also permits to perform a quantification of the target DNA. This is accomplished by measuring a fluorescence signal - which is directly the amount of DNA amplified- during the course of the reaction.
