Water Cycle Second Grade Worksheet – Students are taught about the life cycles of different creatures. For example, a butterfly’s life cycle can be compared to the life cycle of a shark. Students can also learn more about the life cycle and habits of amphibians. This worksheet will help students understand how animals live. Students can complete the worksheet independently and as a class.
Life cycle of a human
Fertilization is the moment when an egg cell from a woman merges with a male sperm cell. This begins the human life cycle. On the sixth day, the single cell divides into a series of smaller ones that burrow into the mother’s womb. These cells begin to form three layers and then bend into an embryo. In this stage, they also begin to differentiate from one another and form the fetal nervous system and circulatory system.
The human body and brain undergo a number of changes during this time. While there are some differences between humans and apes in their lives, they all follow the same basic cycle. For example, humans develop an erect body and show off their movable hands, whereas apes develop great cognitive talents. The food we eat supports a host of changes in the human body and brain after conception.
A human life cycle is structured around a series of developmental stages and age groups. It also includes an infancy period. The average life span of a human is about seventy to eighty years, but this can vary widely depending on the health of the individual.
Life cycle of a butterfly
The Life cycle of a butterfly begins with the butterfly’s egg. The caterpillar’s needs are met by the egg. Most butterflies lay their eggs on leaves. The eggs can be small, round, oval or cylindrical. Monarch butterflies lay eggs on the undersides of plant leaves. They can be either smooth or wrinkled. The eggs hatch within a few weeks.
Once the butterfly has emerged from the pupa, it pumps its blood into its wings. After a few hours, the wings will fully develop and the butterfly will begin to fly. Once the wings have grown, the butterfly will search for food and a mate. Once it has found a mate, it will lay eggs on a leaf.
The next stage is the adult stage. The butterfly lays eggs in spring, summer, and fall. The female butterfly lays a large number of eggs at one time. The eggs may be small. The egg is the basis for the development of the caterpillar (also known as the larva). During this time, it eats continuously and sheds its skin four or five times. It also stores food, which will be used by the adult butterfly.
Sharks live a long life
Sharks have an extremely long life cycle. Sharks can live up to 15 years. Most sharks are born in coastal areas and remain close to the area where they were born until they are fully grown. During this time, sharks grow, mature, and reproduce. Two claspers allow sharks to grasp onto females and insert sperm.
The eggs and sperm are incubated by female sharks for several months before they reach full term. The mother keeps the young sharks inside for about a year before they are born. Some species of sharks exhibit cannibalism, where the first pup is born alive and eats other eggs or pups. These ovoviviparous species have a variable gestation period, which can vary from several months to up to two years. Asexual reproduction is also possible in some species.
Sharks are extremely sensitive to sound waves and have exceptional hearing. The dorsal fins on their heads are located on either side. The lateral line system is made up of narrow canals filled with water that are attached to nerves that transmit signals to the brain.
Amphibian life cycle
Most amphibians have a complex life cycle, starting as a larva and ending as an adult. Hormones and the environment control these life cycles. Thyroid hormones and corticosteroids produced by interrenal glands are the primary morphogens in amphibians and are dependent on input from the hypothalamus and pituitary glands. Ultimately, the hypothalamus regulates the activity of both the thyroid gland and the pituitary gland.
Amphibians are unique in their life cycles. They can reproduce in both water and on land. A frog’s life cycle begins with sexual reproduction. This is when the male lures the egg-carrying women to mate. The females then release their eggs into the water where the males fertilize them with sperm. Most species of amphibians reproduce by external fertilization.
Many species of frogs lay eggs in calm water which protects them against predators. However, some species stay with the eggs to care for them. The eggs become tadpoles once they are fertilized. The tadpoles hatch within one to three weeks.