mesoderm – muscles or skeleton or excretory system or respiratory system or circulatory system (or blood) (iii) Placenta origin: uterine tissue and embryonic tissue [allow from mother and baby] 3 Functions: produces hormones (or named) / allows passage of food (or named)/ and oxygen / antibodies / waste (or named) / acts as a barrier or explained any three 2 3(2) (iv) Progesterone 2 (v) Amnion: sac or membrane holds or produces fluid or protects embryo (or foetus) 2 2 2005 HL Q13 13. (a) (i) Testis 3 (ii) Development of secondary sexual characteristics or example named / development of sex organs /sperm production any two 2(3) (b) (i) Diagram (testis, associated duct, penis) labels 6, 3, 0 2(3) (ii) Testis 3 (iii) Size comment / shape or structural comment / motile (only if ‘tail or ‘flagellum’’ not given)/ chromosomal difference / does not (usually) contribute mitochondrial DNA to zygote any two 2(3) (iv) Cowper’s gland / seminal vesicle / prostate gland 3 (v) Allows sperm to swim / provides nutrients / lubricant / protects sperm 3 (c) (i) Prevention of fertilisation (conception) or implantation or pregnancy 3 (ii) Vasectomy or described Advantage – simple operation/ avoids side effects of hormonal contraception / effective / single procedure Disadvantage – not easily reversed / medical complications / no protection against STIs 3 3 3 (iii) Any three examples 3(3) (iv) Decrease (no increase) in population / demographic imbalance/ improved social conditions /comment on STIs / health issues 3 2006 HL Q15(c) (c) ANY THREE TOPICS (i) menstruation: shedding of endometrium / in absence of fertilisation or low level of progesterone disorder: Endometriosis or fibroids / comment 4+2(3) (ii) Antibodies or immunity / less danger of infection/ uterus contracts / 4+2(3)
2009 HL Q14(b) 14. (b) (i) Example of transport in (or out) / example of barrier / produces progesterone 2(3) (ii) Uterine and embryonic 3 (iii) Change in hormone levels (or correctly described) / contractions / waters break / cervix dilates / delivery / cord cut / afterbirth 3(3) (iv) Sperm and egg fuse / outside the body (or described) 2(3) (v) Morula: Blastocyst: (Solid) ball of cells Fluid-filled (or hollow) ball of cells 3 3 2010 HL Q15(a) 15. (a) (i) Sperm (cells) and (seminal) fluid 3 (ii) Diagram (testis, sperm duct, urethra, penis) Four parts located and named: Testis Epididymis Sperm duct or prostate gland [allow seminal vesicles] Urethra or sperm duct 6, 3, 0 3 3 3 3 (iii) Broken voice (or enlarged larynx) / body hair / more muscle / more bone enlargement of testes / enlargement of penis Any two 2(3) (iv) *Testosterone 3 2010 HL Q15(c) 15. (c) (i) (Sucking or pumping) stimulates (pituitary) / production of hormone (or correctly named hormone) / promotes milk flow Any two 2(3) 20012 HL Q14 14. (b) (i) 1. 2. Ectoderm Mesoderm Endoderm ectoderm: e.g nervous system mesoderm: e.g skeletal system endoderm: e.g. digestive system 3 3 3# 3 3 3 (ii) Embryonic Uterine or endometrium 3 3 (iii) 1. 2. A membrane (or sac) that surrounds the embryo (or foetus) It contains (or secretes) (amniotic) fluid or protects embryo 3 3 2013 HL Q13 13. (a) (i) *Secondary sexual characteristics 3 (ii) *Puberty 3 (iii) *Testosterone 3