Questions and Answers

Describe that discontinuous variation results in a limited number of phenotypes with no intermediates, including ABO blood groups, seed shape and seed colour in peas

Describe variation as differences between individuals of the same species

State that some viruses can pass across the placenta and affect the fetus

Identify, on diagrams, the placenta and umbilical cord and describe their functions in relation to the exchange of dissolved nutrients, gases and excretory products between the blood of the mother and the blood of the fetus (structural details are not required)

State the functions of the amniotic sac and the amniotic fluid

Describe the early development of the zygote, limited to the formation of a ball of cells (embryo) that becomes implanted in the lining of the uterus

Explain the roles of follicle-stimulating hormone (FSH), luteinising hormone (LH), oestrogen and progesterone in controlling the menstrual cycle

Describe the roles of testosterone and oestrogen in the development and regulation of secondary sexual characteristics during puberty

Compare male and female gametes in terms of size, structure, numbers and motility

Describe the process of germination, including the role of enzymes