1. Give reasons for:

1. Man can't reproduce asexually while inhuman.
2. The presence of testes outside the body in a sac-like structure called the scrotal sac.
3. The man, whose testicles are still present inside the abdominal cavity is infertile (sterile).
4. The seminal fluid is alkaline.
5. The seminal fluid contains nutrients.
6. When occurrence a cut in the two vas deferens, the person becomes infertile.
7. The sperms don't die during their passage through urethra.
8. Fallopian tubes are of a funnel-shaped opening provided with finger-like projections.
9. The inner wall of fallopian tubes is lined with cilia.
10. The uterus has a muscular wall.
11. The uterus is lined with mucus membrane rich in blood capillaries.
12. The midpiece of the sperm contains mitochondria.
13. The sperm has a long and thin tail.
14. The ovum is relatively large in size.
15. During fertilization, the head of sperm secretes enzymes on the ovum.
16. Fallopian tubes ligation is considered one of the means of birth control.
17. The ovum surrounds itself with a coat after the penetration of a sperm inside.
18. Zygote carries the complete number of chromosomes.
19. Surgical tools must be sterilized during labour.

Man can't reproduce asexually: Humans reproduce sexually because it allows genetic diversity, which is important for adaptation and survival. Asexual reproduction is not possible in humans due to the complexity of our genetic makeup and reliance on genetic recombination.
Presence of testes outside the body: The testes are located in the scrotal sac outside the body to keep them cooler than the body's core temperature. This lower temperature is essential for the production of healthy sperm.
Infertility due to testicles inside the abdominal cavity: If the testicles remain inside the abdominal cavity, they may become too warm for sperm production, leading to infertility, because sperm develops optimally at temperatures slightly below body temperature.
The seminal fluid is alkaline: This alkalinity helps neutralize the acidic environment of the female vagina, which protects sperm and allows them to survive longer as they travel towards the egg.
The seminal fluid contains nutrients: Nutrients, especially fructose, provide an energy source for the sperm, helping them survive and remain active as they make their way to fertilize an egg.
Infertility due to cuts in the vas deferens: The vas deferens are ducts that transport sperm from the testicles to the urethra. Cutting these ducts (a vasectomy) prevents sperm from entering the seminal fluid, resulting in infertility.
Sperm survival in the urethra: Protective components of the seminal fluid ensure sperm's survival as they pass through the urethra, allowing them to remain viable until ejaculation.
Structure of fallopian tubes: The funnel-shaped openings and finger-like projections (fimbriae) help capture released eggs and ensure their passage through the fallopian tubes.
Cilia lining the fallopian tubes: The cilia's movement aids in transporting the egg towards the uterus, facilitating fertilization by sperm.
Muscular walls of the uterus: The strong muscles of the uterus help in childbirth by contracting to push the baby out and in retaining the fetus during pregnancy.
Uterus lined with mucus and capillaries: This lining provides nutrients to the developing embryo and plays a role in implantation and the placenta's formation.
Midpiece of sperm contains mitochondria: Mitochondria generate the energy needed for the sperm to travel long distances to reach the egg cell.
Tail of sperm: The long and thin tail known as the flagellum propels the sperm, aiding its swimming towards the egg.
Large size of ovum: The ovum is larger because it contains not only the genetic material but also the necessary nutrients to support the early stages of embryo development after fertilization.
Enzymes secreted by sperm head: These enzymes help break down the outer membrane of the ovum, allowing the sperm to penetrate and fertilize the egg.
Fallopian tube ligation for birth control: This surgical procedure blocks the fallopian tubes, preventing eggs from reaching the uterus for fertilization.
Ovum forming a coat after sperm penetration: This prevents other sperms from entering, ensuring that only one sperm fertilizes the ovum.
Zygote chromosome number: The zygote is formed when sperm and ovum unite, resulting in a cell with a complete set of chromosomes from both parents (diploid).
Sterilization of tools during labor: Sterilization prevents infection, ensuring the safety and health of both mother and child during delivery.