Earth life and science

• The origin of life could be explained by the spontaneous generation theory which states that life forms can be generated by inanimate objects.
• Francesco Redi was able to disprove the spontaneous generation theory by experimenting with meats.
• Lazaro Spallanzani also disproved the spontaneous generation theory by performing experiments using a broth.
• Alexander Iparin, a Russian scientist, hypothesized that the atmosphere of primitive earth contained gases like ammonia, methane, hydrogen, and water vapor.
• Stanley Iparin performed an experiment using a mixture of gases suggested by Iparin and electrical sparks.
• Robert Hooke coined the term cell and was responsible for the beginning of cytology.
• Anton van Leeuwenhoek was the first to see individual cells and recognized them as living units.
• Mathias Schleider and Theodor Schwann stated that all plants are made of cells.
• Rudolf Virchow found out that cells divide to form new cells.
• Robert Brown discovered the nuclei within the cell.
• Cytology is the study of cells.
• Life starts from a cell- fertilized egg or zygotes.
• The cell, which is the structural unit of life, consists entirely of chemical substances.
• The chemical composition of organisms consists of inorganic compounds like Acid, bases, salts and water, and organic compounds like carbohydrates, lipids, proteins, and nucleic acids.
• Cell membranes, also called plasma membranes, are the structures that control the movement of substances in and out of the cell.
• Cytoplasm is found inside the cell membrane surrounding the nucleus.
• Mitochondria are the power house of the cell.
• Ribosomes are involved in a process called protein synthesis.
• Endoplasmic Reticulum serves as channels which are transported in the cell.
• Golgi Complex serves as the packaging factories of the cell.
• Lysosomes are spherical sacs that contain powerful digestive enzymes.
• Plastids are energy converters.
• Vacuoles store food.
• Vesicles carry substances in and out of the cell like food particles.
• Microtubules provide support and movement to the cell.
• The nucleus controls all the activity in the cell and contains DNA, rna, and proteins.
• Cell membranes, also known as plasma membranes, are the structures that control the movement of substances in and out of the cell.
• Cytoplasm is located inside the cell membrane surrounding the nucleus.
• The nucleus controls all the activity in the cell and contains DNA, RNA, and proteins.
• Prokaryotes and eukaryotes are the two basic cell types.
• Prokaryotes lack a true nucleus.
• Eukaryotes have a true nucleus.
• Pollination is the transfer of pollen grains from the anther to the stigma of a flower.
• Self-pollination is the transfer of pollen from the same flower.
• Cross-pollination is the transfer of pollen from one flower of one plant to another plant.
• Agents of pollination include insects, wind, water, birds, and humans.
• Fertilization is the process where the pollen grain that lands on the stigma develops a pollen tube that grows down through the style and into the ovary where the ovule is located.
• The sperm travels down the pollen tube and fertilizes the egg cell inside the ovule.
• The fertilized egg, called the zygote, develops into the embryo.
• The ovule becomes the seed.