The phases of Meiosis.
Introduction to bacteria
Clarifying some points on evolution and intelligent design.
Micturition (peeing) starts with urine flowing from the kidneys to the bladder via ureters. The bladder expands using transitional epithelium. Urine exits through the urethra, controlled by internal and external urethral sphincters. Ureters prevent backflow, thereby reducing infection risk
Skeletons support and protect our bodies. Bugs have exoskeletons outside their bodies, while humans have endoskeletons inside. Our bones are in axial (skull, ribcage, spine) and appendicular (arms, legs) groups. Bone marrow makes blood cells; more specifically, red marrow makes blood and yellow marrow stores fat.
From the extinction of the dinosaurs to humanity.
DNA is made up of two strands. Each strand has a backbone made up of alternating sugars and phosphate groups. The two strands are linked by complementary nitrogenous bases. The strands are oriented in opposite directions, making the structure "antiparallel".
Molecular structure of DNA. Nucleotide. Nitrogenous base, phosphate.
Learn about DNA (deoxyribonucleic acid). Overview of DNA bases, complementary base pairing, and the structure of the double helix.
Overview of fertilisation and early human development. From conception leading to a zygote to blastocyst, embryo and fetus.
