C. Xylem moves water up, and phloem moves food down
Answer:
Post reproductive isolation → Hybrid sterility
Explanation:
The biological concept of species states that individuals of a species can not mate and reproduce with individuals of another species. But if they get to reproduce, the progeny will not be viable or fertile. There will not be any reproductive success.
There are different reproductive isolation mechanisms, which are barriers that inhibit or interrupt the genetic flow between different species.
Reproductive barriers are isolation mechanisms that prevent mating between two or more species. The prezygotic mechanism avoids fertilization between individuals of different species, while the postzygotic mechanism impedes the zygote to develop and reach the adult stage.
Postzygotic mechanisms or barriers include
- Hybrid inviability,
- Hybrid sterility,
- Hybrid decreased viability or fertility,
- Cytoplasmic interactions.
In the exposed example, it seems that the mountains separating the frogs´ populations made a place for the development of postzygotic barriers, specifically hybrid sterility. Frogs from one population get to mate and produce offspring with the frogs of the other population, but their progeny is sterile.
Answer: Both cell types will undergo aptosis
Explanation:
cells lacking both Bax and Bak, but not cells lacking only one of these components, are completely resistant to tBID-induced cytochrome c release and apoptosis. Moreover, doubly deficient cells are resistant to multiple apoptotic stimuli that act through disruption of mitochondrial function: staurosporine, ultraviolet radiation, growth factor deprivation, etoposide, and the endoplasmic reticulum stress stimuli thapsigargin and tunicamycin. Thus, activation of a “multidomain” proapoptotic member, BAX or BAK, appears to be an essential gateway to mitochondrial dysfunction required for cell death in response to diverse stimuli.
The correct answer would be A, C and D. The C4 pathway produces large amounts of carbohydrates, involves the activity of Rubisco and is the mechanism of photorespiration. This is also known as the Hatch-Slack pathway and is a photosynthesis process that occurs in some plants.
A mixture consists of two or more substances which may be elements, compounds or both mixed together physically in any proportion, but not chemically combined. However, a compound consists of two or more elements that are chemically combined in a fixed proportion. Hence, a compound is different from a mixture.