Human evolution overview
From the extinction of the dinosaurs to humanity.
From the extinction of the dinosaurs to humanity.
Molecular structure of DNA. Nucleotide. Nitrogenous base, phosphate.
Outcomes:
Meiosis is a process that creates sex cells (gametes) with half the number of chromosomes of the parent cell. Meiosis has two stages: meiosis I and meiosis II. In meiosis I, homologous chromosomes pair up and exchange genetic material (crossing over). In meiosis II, sister chromatids separate, creating four haploid cells.
How homologous chromosomes separate into two sets. Prophase I, metaphase I, anaphase I, and telophase I.
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.
This online resource introduces the geocentric and heliocentric models. Exoplants, planets and their motions, planetary orbits, the role of gravity and how the solar system was formed are also covered.
This fascinating video details the journey that a group of friends made in Nevada. Their aim was to illustrate the solar system to scale.
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