Sperm and Egg Reproduction: Fertilisation and Development in Animals

1. Reproduction SQA questions

2. Sperm and eggs WYSK ametes ales arge • Sperm are the sex cells (g_______) produced by m_____ in very l____ numbers but are much s_____ than eggs. Sperm have t_____ to s_____ and have limited f____ stores • Eggs are the s__ c___ (gametes) produced by f______ in s_______ numbers than sperm. They are much _______ than sperm as they contain a large f_____ s_____ maller ails ood wim ex ell emales maller larger ood tore

3. Fertilisation WYSK ametes perm ale • Male g_______ (s______) contains the m____ nucleus and the female gamete (___) contains the f______ n_________ • Each nucleus contains h____ the genetic i___________ needed for a new animal • Fertilisation is the j_______ of the male nucleus and female nucleus which combines the g_______ i_________ egg emale ucleus alf nformation oining enetic nformation

4. Internal/external WYSK eposited • In some fish, sperm are d_______ in the w_____ close to the e____. • In m________ sperm are deposited inside the b_____ of the f_______. • Internal fertilisation is needed in l_____ living animals so that there is f______ for the sperm to s____ to the egg. ater gg ammals ody emale and luid wim

5. Testes/ovaries WYSK estes • Sperm are produced in t_______. • Eggs are produced in o________ and are released into the o________ where in m________ f___________ takes place varies viduct ammals ertilisation

6. oviduct Sperm tube urethra ovary testis uterus vagina penis produces sperm C oviduct produces eggs ovary

7. oviduct sperm tube ovary uterus penis vagina testis oviduct penis produces eggs produces sperm C Embryo develops here / implantation

8. nucleus nucleus water amniotic

9. Development WYSK lexible overing ood ac olk • In fish, eggs are protected by a f_______ c_________ and the embryos obtain f_____ from the y____ s___. • In a fish such as a t______ the young emerge from the eggs able to m________ themselves • In mammals the fertilised egg passes down the o________ and becomes a________ to the wall of the u_______. • The mammal embryo develops in the fluid of the a______ s___ and obtains its food from the m_________ blood circulation • At birth the young of mammals are dependent on the adult for c___ and p_________ rout aintain viduct ttached terus ac mniotic aternal are rotection

10. Placenta CREDIT inger rojections • The placenta is a flat, disc like structure with many f______ like p_________. • These finger like projections help the placenta to e________ substances between the mother and the embryo’s b______ • G______ and oxygen d______ across the p_______ from the m______ blood to embryo’s blood • CO2 and w______ diffuse across the placenta from the e________ blood to the m________ blood xchange lood iffuse lucose lacenta other’s astes mbryo’s other’s

11. Number of eggs CREDIT arental are • The morep________ c_____ given by adults then the lesse____ or y______ need to be produced • Fish have l_____ parental care and therefore produce l____ of eggs and young • Mammals have lots of p_______ c____ and therefore produce few e_____ and y_____ ggs oung ess ots arental are ggs oung

12. division fertilisation oviduct ovary uterus cervix vagina

13. 3 divides fertilisation 2 ovulation 1 4 implantation fertilisation division implantation baby develops

14. Human Embryo 4 5 1 2 6 amniotic sac 3

15. Development in Fish 1 Fish embryo flexible covering 2 3 Yolk sac

16. Placenta mother’s blood vessels – A and B embryo’s blood vessels – C and D