Answer:
d. They are often keystone species
Explanation:
Top predators in an environment are the largest predators and sits on the top (apex) of the food chain in an ecosystem which do not have any natural predators.
As the top predators relative to its abundance has disproportionately large effect on its natural environment, they are the keystone species most of the time.
Hence option d. They are often keystone species is the right option.
I belive the correct answer is D
Hope this helps :)
Answer:
b. False
Explanation:
These components are not sufficient to successfully perform a PCR reaction. Deoxynucleoside triphosphates (dATP, dGTP, dCTP, dTTP) are missing so that the PCR reaction can occur perfectly.
The PCR technique allows a specific fragment of the DNA molecule to be amplified thousands of times in just a few hours. This technique revolutionized research in molecular biology because it had taken a long time for DNA amplification. From PCR it is possible to obtain enough copies of a part of DNA to detect and analyze the sequence that is the target of the study.
For a PCR reaction to be performed a solution with some components must be prepared. These components are:
- Magnesium chloride buffer (to optimize reaction and act as a cofactor for polymerase)
- Forward and reverse primers (to customize the start of the enzyme reaction)
- DNA polymerase (Enzyme required for replication of desired DNA region.)
- DNA Template (the DNA to be copied)
- PCR-grade water
- Deoxynucleoside triphosphates: dATP, dGTP, dCTP, dTTP (act as bricks in the construction of DNA molecules).
Answer:
double fertilization
Explanation:
Flowering plants or angiosperms are seed-producing plants with the ability to produce reproductive organs-flowers and fruits with seed in it (unlike gimnosperms which contain naked seed). Another distinctive feature of angiosperms is their reduced gametophytes. This feature most likely reduces the time between pollination and fertilization. Fertilization in flowerin plants is double, meaning that two sperm cells fertilize ovule cells(egg cell and central nuclei cell): one forms diploid zygote which will develop in embryo, while other form triploid cell which will develop into endosperm (provides nutrition for the embryo).
