Answer:
the two reactants of cellular respiration are oxygen and glucose.
The reactants of photosynthesis are water, carbon dioxide and light energy.<span>Plants use these reactants to make the food that is essential for plant growth.</span>
If a zebra mussel is discovered in a lake in Pennsylvania, then the ecologist would be worried because it is an invasive species. The zebra mussel is native to Ukraine and Russia, but if it has been found in Pennsylvania, than it means that it has been introduced in this area. As an invasive species, the zebra mussel can be very dangerous for the native species in the lake. The invasive species usually are more competitive for food sources than the native species, manage to reproduce quicker, bring in diseases, and the native species tend to not have defense mechanisms for them. This leads to rapid decline or even extinction in the native species, while the invasive spreads out quickly and takes over, resulting in dramatic change in the whole ecosystem.
Answer:
- One spermatogonium produces 4 spermatids FALSE. One primary spermatocyte produces 4 spermatids.
Explanation:
Germ cells are diploid reproductive cells in charge of gamete production. Germ cells divide by mitosis and meiosis. Through mitosis, they originate more sexual cells, but through meiosis, they produce gametes -sperm and egg cells-. This process is known as gametogenesis.
Gametes´destiny is to merge during fecundation, and a new diploid cell called zygote emerges through fertilization. The zygote is a complete cell and suffers successive mitosis to form the new organism.
Spermatogenesis is the process of production and maturation of sperm cells. Spermatogonia are the masculine diploid germ cells, carrying 46 chromosomes. These germ cells suffer mitosis to reproduce. Some of them stay as spermatogonia, and some others become primary spermatocytes, which are in charge of gamete production. Primary spermatocytes are also diploid cells, meaning that they still carry 46 chromosomes.
Each primary spermatocyte replicates its genetic material and then goes through meiosis I to produce two daughter haploid cells called secondary spermatocytes, each of them carrying 23 chromosomes. Each secondary spermatocyte will produce two other haploid daughter cells by meiosis II.
The total result from the two cellular divisions of each primary spermatocyte is four haploid daughter cells called spermatids.
During spermiogenesis, spermatids mature into spermatozoa or sperm cells. Each sperm cell characterizes by being composed of a head, midpiece, and tail.
- DNA replicates once, but cells divide twice TRUE
- The products are spermatozoa that each have a head, midpiece, and tail TRUE
- Spermatids containing 23 chromosomes (1n) are produced TRUE
- One spermatogonium produces 4 spermatids FALSE. One primary spermatocyte produces 4 spermatids.
- Genetically diverse spermatids are created TRUE
