B, a nucleus. Nuclei are membrane-bound organelles inside eukaryotic organisms. Eukaryotes are protists, fungi, plants, and animal cells. A bacteria is not a eukaryote, it is a prokaryote, so it does not have the membrane-bound structure of the nucleus.
Be careful, though, bacteria still have DNA. It is simply located in the center of the cell and is not encased in a membrane.
Answer:
A genetic engineer would be most likely to genetically modify the chickens, with the trait being production of unfertilized eggs. (B)
Answer:
A substance that cannot be broken down into chemically simpler components is an element.
A substance that can be broken down into chemically simpler components (because it has more than 1 element) is a compound. Example: Water id a compound composed of elements hydrogen and oxygen.
Answer:
option A is correct because of it is undergoing a convertion
1) When a star's temperature or size increases, its luminosity increases. In other words it seems more bright.
2) The electromagnetic spectrum is used to determine different types of light waves (infrared, visible light, x-rays etc.) which produced by different kinds of astronomical objects.