The plant cell is the smallest living structure and constituent unit of all plants. Its size and shape vary by function. It is composed of several organelles, all useful to its activity.
The right answers are: (the numbers are in the picture).
1 refer to a vacuole.
2 refer to a cell wall (if you see closer, the arrow is aiming the green layer, the yellow one is the cell membrane).
3. refer to a chloroplast.
4. refer to mitochondria.
During meiosis in cell division, oogenesis refers to the production of female reproductive cells, while spermatogenesis refers to the production of male reproductive cells. This determines the reproductive capacity of an organism during and after cell division.
The Universe is defined to be the sum total of everything that we know about: stars, galaxies, clusters, superclusters, voids, etc.
Cosmology is the study of the structure and evolution of the Universe.
It is a subject of great current interest, as the Hubble Space Telescope and other new instruments have recently helped astronomers shed light on many important questions.
There have been many theories about the Universe, but they generally all share one fundamental postulate, the cosmological principle, which has two parts. First, the Universe must be isotropic (the same in every direction).
For example, the Hubble deep field images, extending 12 Gly away, for two completely different directions, are remarkably similar:
Yes, C4 is a process used by plants to survive in hot dry climates along with the CAM cycle. Hope this helps!
