Neuclear bases. the four are molecules called <span>adenine, thymine, cytosine and guanine.</span>
Answer:
well the chloroplasts are the part of the cell that make photosynthesis happen
For number one, the shadows are longest at sunrise and sunset, and these are different from the ones cast at noon because they are longest and darkest. Hope this helped! I'll probably come back to help with the second one after I do more research :)
Answer:
The description is provided in the explanation section below
Explanation:
ALTERNATION OF GENERATIONS is a unique phenomenon whereby certain organisms switch between a diploid state and a haploid state in their reproductive life cycle. It is a feature of plants (higher and lower).
A plant is a diploid organism (2n) i.e. contains two set of chromosomes. This diploid state of the plant is called the SPOROPHYTE. The diploid sporophyte (2n) of a plant undergoes meiotic division (reduction division) to produce haploid spores. These haploid spores germinates and grows via mitosis (duplication division) to form the haploid GAMETOPHYTE.
The haploid gametophyte (n), via structures called GAMENTAGIA, produces haploid gametes. The male gametophyte produces male gametes (sperm) while the female gametophyte produces female gamete (egg). These haploid gametes eventually fuse in a process called FERTILIZATION to produce a diploid ZYGOTE (2n) i.e. sperm (n) + egg (n) = zygote (2n). The ZYGOTE undergoes series of mitotic divisions (growth) to form the diploid SPOROPHYTE (2n) of the plant. The cycle restarts again in that order, hence it is called ALTERNATION OF GENERATIONS.
N.B: Mitosis maintains the number of chromosomes of the parent cell while meiosis reduces the chromosomal number of the parent cell by half.
