Learn step-by-step how mammals reproduce, including key terms like internal fertilization, pregnancy, and birth, explained simply for young students.
Mammals are a group of animals that include humans, dogs, cats, whales, and many others. One thing all mammals have in common is how they reproduce to have babies. Let's explore this step-by-step.
Most mammals reproduce through a process called internal fertilization. This means that the male's sperm fertilizes the female’s egg inside her body. The male produces sperm, and the female produces eggs (also called ova).
During mating, the male deposits sperm into the female's reproductive tract. Inside the female’s body, one sperm meets and fertilizes an egg. This fertilized egg is called a zygote.
The zygote starts dividing and eventually becomes an embryo. In mammals, the embryo grows inside the female's uterus (womb). The female provides nourishment to the developing embryo through a special organ called the placenta. The placenta attaches to the wall of the uterus and connects to the embryo by an umbilical cord, which delivers oxygen and nutrients.
The time the embryo grows inside the mother is called pregnancy. The length of pregnancy varies between mammal species. For example, humans are pregnant for about 9 months, while other mammals may have shorter or longer pregnancies.
When the baby mammal is fully developed, the mother gives birth. Unlike animals that lay eggs, most mammals give birth to live young. After birth, the mother often feeds the baby milk from her mammary glands. This milk provides important nutrients and helps the baby grow strong.
This reproductive process helps mammals ensure their babies develop safely and are cared for after birth.