Sexual reproduction Flashcards
Sexual reproduction
Requires gametes (sex cells) Produces genetically varied offspring Involves meiosis and mitosis
Asexual reproduction
Does not involve gametes
Produces genetically identical offspring
Involves mitosis
Sperm
Male gamete
Produces in testes
Are mixed with a fluid called semen
Egg cell
Female gamete
Produces in ovaries
Fertilisation
Is the fusion of a male and female gamete (each with 50% of the information needed) they have 23 chromosomes each.
It is now a ZYGOTE
Cell division
The process in which cells split in half again and again.
Zygote–>embryo
A ball of 32 cells will implant in the lining of the uterus
Placenta
Secretes progesterone to ensure the uterus lining remains thick
It allows nutrients and oxygen to move from mother to embryo
Waste materials and carbon dioxide to move from the embryo to the mother
Because the placenta does not allow the mother and babies blood to mix it prevents
Any illness being transferred
Damage to tissue due to the mothers high blood pressure
White blood cells attacking foreign blood
Mentrsual cycle days 1-5
Uterus lining sheds if no fertilised egg is implanted
Menstrual cycle days 6-10
Uterus lining begins to thicken again in preparation for an egg
Menstrual cycle days 11-18
Ovulation occurs as a new egg is released from the ovaries
Menstrual cycle days 19-28
Uterus lining continues to thicken
Puberty in boys
Voice breaks Sperm production begins Shoulders broaden Facial, armpit, chest and pubic hair growth Greater muscle development Growth and development of genitalia Possible mood swings and acne
Puberty in girls
Voice deepens Menstrual cycle begins Pelvis broadens Armpit and pubic hair growth Muscle development Fat deposits on breaths, hips and thighs Growth and development of genitalia Possible mood swings and acne
