Lesson Starter How many eggs does the female release? What is fertilisation? Where in the body does fertilisation take place? What is the zygote?

Reproduction in animals and plants Lesson 4

Development into a baby Lesson 4 Development into a baby

After fertilisation The egg and sperm FUSE in the FALLOPIAN TUBE during FERTILISATION After fertilisation the cell continues to divide The ball of cells IMPLANTS in the UTERUS

After fertilisation The ball of cells becomes an EMBRYO Some of the cells form organs- the others form the PLACENTA

The placenta The baby gets everything it needs from its mother’s body Placenta connects the baby and mum Mother and baby’s blood comes into very CLOSE CONTACT but never mixes

The placenta Nutrients and oxygen pass from the mothers blood to the baby Waste products and carbon dioxide pass from baby to mother- mum gets rid of baby’s waste

The umbilical cord The UMBILICAL CORD connects the baby to the PLACENTA Contains large blood vessels that carry nutrients and oxygen to the baby and waste/co2 away from the baby

Complete the questions on page 9 of your reproduction booklets Task Complete the questions on page 9 of your reproduction booklets

Embryo development The cells continue to divide in the UTERUS They form the organs and systems in the baby’s body Early stages = embryo 8 weeks= foetus

3 weeks The baby-in-the-making is a ball of cells called a BLASTOCYST. The blastocyst contains a full set of DNA from mum and dad, which determines sex, eye colour, and other traits.

6 weeks Ball of cells looks like a tadpole Has a head end and tail end Heart begins to form

8 weeks Can now see eyes Arms and legs have formed with tiny fingers and toes Baby is called FETUS

12 weeks Can kick its legs and move fingers Internal organs are working

18 weeks Mum should feel baby moving from inside her tummy

24 weeks Baby's taste buds are developing. Brain is growing very quickly, and hair may be growing, too. About a foot long and weighs just over a pound.

32 weeks Baby has grown little fingernails and toenails. Almost 17 inches long (head to heel) and weighs about 3 3/4 pounds.

37-40 weeks Baby is now considered full-term. Lungs should work fine if he's born now Baby’s head is just above the cervix- when muscles in the mum’s uterus contract- the head will be born first