State Changes Changes of state are?physical changes?that are reversible These changes do not change the chemical properties or chemical makeup of the substances involved Vaporization?includes?evapo...
Balancing Equations A?symbol?equation is a shorthand way of describing a chemical reaction using?chemical symbols?to show the number and type of each atom in the reactants and products A?word?equat...
Elements & Compounds Elements are substances made from one kind of atom Compounds are made from two or more elements?chemically combined Elements take part in chemical reactions in which new su...
Annotating the Seminiferous Tubule and Ovary Annotating the Seminiferous Tubule The testes contain many small tubes, or?tubules, known as?seminiferous tubules The production of sperm, or?spermatoge...
Assessing the Risks of Oestrogen Pollution NOS: Assessing risks and benefits of scientific research: the risks to human male fertility were not adequately assessed before steroids related to proges...
The Placenta & the Exchange of Materials Mammals can be split into different categories on the basis of their?mechanism for foetal nourishment Placental?mammals, such as humans Monotremes, or e...
Role of hCG in Early Pregnancy Shortly after the developing embryo implants into the endometrium it begins secretion of the hormone?human chorionic gonadotropin?(hCG) hCG is secreted during the fir...
Implantation of the Blastocyst Following human fertilisation, the newly?fertilised ovum divides by mitosis?to form?two diploid nuclei?(i.e. each nucleus contains two sets of chromosomes) and the cy...
Preventing Polyspermy Fertilisation is the?fusion?of?one sperm cell?and?one ovum; this fusion of two haploid nuclei gives rise to a diploid zygote During sexual reproduction,?many sperm are release...
