Answer:
Lack of food, increase in predators, lack of space, too much competition within the population, lack of water
Explanation:
Answer:
vaccination
Explanation:
The vaccination has been one of the most revolutionary inventions in the medical field. This invention helped protect people from numerous diseases, some being totally neutralized, while some having only minor effects on the human body. The vaccination basically is a way of enhancing the immune system of the body by injecting in it a weakened form of the pathogen. In this way, the weakened form of the pathogen is not capable to harm the body, and the body is not fighting against it, but instead the pathogen becomes part of the body and its defense mechanism, so when the pathogen strikes, the body has a counter attack and defeats it.
Answer:
the symbol for nitrogen is N
Explanation:
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
