The Human Reproductive System Label Quiz – Anatomy Practice

Pregnancy officially begins when the zygote, which is the fertilized egg cell, implants itself into the uterus. This is the point at which the pregnancy is established and the development of the embryo begins. Prior to implantation, fertilization may have occurred, but pregnancy is not considered to have officially started until the zygote attaches to the uterine lining.

During meiosis in a human female, one haploid egg cell and three polar bodies are produced. Meiosis is the process of cell division that results in the formation of gametes (sex cells). In females, meiosis begins before birth and is completed during ovulation. During meiosis I, the primary oocyte divides unequally to produce a secondary oocyte and a polar body. The secondary oocyte then undergoes meiosis II, resulting in the formation of a haploid egg cell and another polar body. The polar bodies are non-functional and eventually degenerate, while the haploid egg cell is released during ovulation and can be fertilized by a sperm cell.

Internal fertilization is the correct answer because it is a reproductive adaptation that is characteristic of most terrestrial vertebrates. This process involves the union of sperm and egg inside the female's body, which increases the chances of successful fertilization and protects the developing embryos from external threats. Most aquatic vertebrates, on the other hand, typically rely on external fertilization where eggs and sperm are released into the water and fertilization occurs externally.

The ratio of 4:1 suggests that one male primary sex cell produces four gametes, while one female primary sex cell produces only one gamete. This is because during meiosis, males produce four functional sperm cells through spermatogenesis, while females produce only one functional egg cell through oogenesis.

Stem cells are undifferentiated cells, meaning they have not yet specialized into a specific cell type. This unique characteristic allows them to develop into different types of cells as needed by the body. Unlike other cells, which have a specific function and structure, stem cells have the potential to differentiate into various cell types, such as muscle cells, nerve cells, or blood cells. This ability makes them valuable for medical research and potential therapeutic applications. Stem cells are not larger than other cells, do not absorb broken cells to repair them, are not found only in plants, and can be found in both embryonic and adult cells.

After a zygote has formed, the process that occurs immediately is mitosis. Mitosis is a type of cell division that results in two daughter cells with the same number of chromosomes as the parent cell. In this case, the zygote, which is formed by the fusion of sperm and egg, undergoes mitosis to divide and produce more cells. This process is crucial for the growth and development of the organism.

The correct answer is A and C. This is because diagram A represents binary fission, which is a common form of asexual reproduction in single-celled organisms. Diagram C represents budding, another form of asexual reproduction where a new organism grows out of the parent organism. Both of these processes involve the production of offspring without the involvement of gametes or fertilization.

FSH is a pituitary hormone that stimulates the growth of the follicle. The follicle is a structure in the ovary that contains an immature egg. FSH plays a crucial role in the development and maturation of the egg within the follicle. By stimulating the growth of the follicle, FSH helps prepare the egg for release during ovulation. This hormone is essential for the reproductive cycle in females and is regulated by a negative feedback system involving the hypothalamus and the ovaries.

If mitosis was not accompanied by cytoplasmic division, it would result in one cell with two identical nuclei. Mitosis is the process of cell division that produces two identical daughter cells. Normally, during cytoplasmic division, the cytoplasm is also divided between the two daughter cells. However, if cytoplasmic division does not occur, the two nuclei would remain within the same cell, resulting in one cell with two identical nuclei.

Identical twins develop as a result of fertilization of one egg by one sperm. This occurs when a single fertilized egg, also known as a zygote, splits into two separate embryos. The embryos will have the same genetic material because they originated from the same fertilized egg. This is different from fraternal twins, which develop from the fertilization of two separate eggs by two separate sperm.