fertilisation + prenatal development

Question 1

stages of prenatal development

Answer 1

• germinal 0-2 weeks
• embryonic 3-8 weeks
• foetal 9-38 weeks or until birth

Question 2

1 sperm

Answer 2

• the male sex cell (gamete)
• contains genetic information from the father
• produced in the testes during puberty

Question 3

2 ovum

Answer 3

• ‘egg’
• female sex cell
• contains the mothers genetic information
• females are born with all of them
• stored in the ovaries

Question 4

3 fertilization

Answer 4

• the fusing of a sperm and an egg cell
• marks the beginning of pregnancy
• also known as conception

Question 5

4 zygote

Answer 5

a full cell resulting from the fusion of an egg and sperm

Question 6

5 morula

Answer 6

the zygote takes on a spherical shape known as a morula

Question 7

6 blastocyst

Answer 7

a thin walled hollow structure consisting of a cluster of cells making up an outer shell that becomes the placenta

Question 8

7 endometrium

Answer 8

the nutrient-rich lining of the uterine wall that the blastocyst embeds in or is expelled during menstruation

Question 9

8 implantation

Answer 9

when a cluster of cells that will become an embryo attaches itself to the endometrium

Question 10

germinal stage

Answer 10

0-2 weeks
- starts at fertilization
- ends at implantation
- when fertilized the zygote begins dividing as it travels down the fallopian tubes and forms a morula

Question 11

embryonic stage

Answer 11

3-8 weeks
- implantation is complete
- baby is referred to as an embryo
- cells divide rapidly and start taking on specialized roles (cell differentiation)
- neural system develops
- limbs, facial features, body organs, tiny muscles begin to develop
- most critical time for human development
- most at risk of teratogens

Question 12

fetal stage

Answer 12

9-38 weeks or birth
- known as a foetus
- ears functioning
- sex can be distinguished
- tongue develops tastebuds
- eyelids separate and open
- fingers and toenails grow
- eyelashes and eyebrows grow
- movements are more coordinated
- starts to move to the head down position in preparation for birth and lungs develop

Question 13

the placenta

Answer 13

• a temporary, disc shaped organ
• allows the transfer of nutrients, gases and wastes between mother and foetus.
• supplies oxygen, nutrients and immune support
• removes wastes such as urine and carbon dioxide

Question 14

placenta as the “life support system”

Answer 14

• the placenta is the baby’s only way to receive nutrients and oxygen
• acts as a kidney, lung and digestive system for the foetus