Contraception, STIs, and Plant Reproduction

Sexually Transmitted Infections (STIs) are spread through various sexual contacts, including vaginal, anal, and oral sex.

STIs are caused by pathogens, like bacteria, viruses, or parasites. These pathogens can be transmitted through bodily fluids, including blood, semen, and vaginal fluids.

Some STIs are curable with antibiotics or other treatments (e.g., syphilis, gonorrhea, chlamydia). However, other STIs, like HIV or herpes, are not curable, but their symptoms can be managed.

Angiosperms are flowering plants, and their defining characteristic is their flowers, which are essential for reproduction.

Asexual reproduction is the process when a plant self-pollinates, creating a genetically identical copy of itself. This happens when pollen from the same plant's stamen reaches its own carpel.

Sexual reproduction in plants happens through cross-pollination. Pollen from one plant is transferred to the carpel of a different plant, resulting in genetic variation.

Contraception refers to methods used to prevent pregnancy after sexual intercourse. These methods include hormonal, barrier, and other techniques meant to create an unfavorable environment for sperm and eggs.

Hormonal contraceptives, like birth control pills, use hormones to stop ovulation, preventing the release of an egg. This prevents fertilization and pregnancy. Hormones also thicken cervical mucus, hindering sperm from reaching the egg.

Barrier methods of contraception create a physical barrier between sperm and the egg. Examples include condoms and spermicides, which can also help prevent some STIs.

This group of contraceptives involves creating an environment unfavorable for sperm and eggs, ultimately preventing fertilization. More research is needed to fully understand this category.

This is the process of producing male gametes (sperm), which travel to the egg in a liquid called semen. The process starts in the testes, producing both sperm and the hormone testosterone, which helps the male body develop and is crucial for sexual characteristics.

The epididymis is a tube where sperm is stored after it is produced in the testes. It is the next step in the journey of sperm.

The vas deferens is a long tube that connects the epididymis to the seminal vesicles. Sperm travels through this tube.

Seminal vesicles are glands that produce seminal fluid - the liquid carrying sperm. The fluid provides nourishment for sperm.

The prostate gland is a gland that produces fluid to protect and help sperm navigate the environment.

Cowper's gland produces a mucus that helps clear the urethra before sperm release, facilitating its journey out of the body.

Pregnancy refers to the period from conception to birth, typically lasting around nine months. During pregnancy, a fetus develops inside the mother's womb.

The process of birth is triggered by hormones from the placenta and the baby's pituitary gland. Uterine contractions push the baby out of the cervix. The amniotic sac bursts, releasing fluid to assist the baby's passage through the birth canal.

The gestation period for a human pregnancy is about nine months, divided into three trimesters. The embryo becomes a fetus around the middle of pregnancy. The primary change after 20 weeks is growth and expansion of existing body systems. Sex determination is possible around 10-12 weeks.

Genetic abnormalities refer to variations in chromosomes or genes that can cause health issues. They can be detected through amniocentesis or chorionic villus sampling (CVS) , which test fetal tissue or amniotic fluid.

Self-pollination is the process of a plant fertilizing itself, creating a clone. This type of pollination does not produce genetic variation.

Cross-pollination involves pollen moving from one plant to another, resulting in genetic variation. It requires an external factor to transfer the pollen, such as wind, water, insects, birds, or animals.

Living pollinators, like bees, birds, and animals, are generally more efficient than wind or water in transferring pollen. The colorfulness of petals (corollas) and nectar production help attract these pollinators for cross-pollination.

After pollination, a fruit develops, containing seeds with an embryo and nutrients. The fruit helps disperse these seeds.

The embryo develops into a fetus within the uterus. Specialized cells form the placenta, which provides nutrient and hormone transfer between the mother and the fetus. The amniotic sac, filled with fluid, protects the embryo.

The placenta is a temporary organ that helps in nutrient and oxygen transfer between the mother and the baby. Waste and carbon dioxide are also exchanged through the placenta, which connects to the fetus via the umbilical cord.

Counter-current flow in the placenta allows efficient exchange of materials between the mother and the fetus. The mother's and baby's blood never mix, preventing blood type incompatibility.