The endocrine system uses chemicals
I believe the answer is a. crossing over
Chromatids are only called as chromatids when they are sister chromatids, meaning that when chromosome have two double stranded DNA attached together, each of the double stranded DNA is a sister chromatid, and while the whole thing (the two sister chromatids that are attached together) is called a chromosome.
So after the DNA has been replicated, the chromosome consist of 2 sister chromatids, attached to each other at their centromere.
Overall, sister chromatid is one of the two double stranded DNA in a replicated chromosome, and chromosome is the whole "X" shape that we see. For example, in humans, after the S phase of interphase in the cell cycle, we have 46 chromosomes, with 92 chromatids, since each chromosome is an "X" shape, by having two sister chromatids.
Hope this helps!
Answer:
Statement A - cellular membrane
Statement B - eukaryote
Statement C - spore
Statement D - prokaryote
Explanation:
The cell membrane is a protective layer present around the cell and cell organelle that regulates and allows different molecules to enter and exit to regulate homeostasis.
Eukaryotes are the organism that can be unicellular or multicellular with the cells contain a nucleus in it.
Spores are reproductive cells that has a resistant layer that protects the cell from an unfavorable condition and capable to form an adult.
An organism that is unicellular and lacks the nucleus is known as a prokaryote and bacteria is an example of such organisms.