What are three disadvantages of sexual reproduction in mammals?
It requires 2 parents and 2 cells to form offspring Requires energy to find a mate therefore less efficent Requires complex functional, structural and behaviroual processes
What are three advantages of sexual reproduction?
Genetic strengths from both parents Beneficial mutations Remove harmful mutations
What are the two types of gametes and what do they do?
Sperm - code for males parental traits Ovum - coding for female parental traits
What is a zygote?
A fertilised egg (sperm + ovum)
What is spermatogenesis?
The formation of sperm
Where does spermatogenesis occur and how?
Occur in the seminiferous tubules of the testes Happens by meiosis of initial cells in the wall of tubules - produces millions of sperm daily
What are the five parts of the sperm cell pathway?
Seminiferous tubules Epididymis Vas deferens Ejactualory duct Urethra
What is semen made of?
Sperm cells along with secretions from the three accessory glands - -seminal vesicle - bulbourethral - prostate
What is the function of the seminal vessels for semen production? (2)
Secrete fructose - energy for sperm Prostaglandins - facilitates uterine contractions
What do prostate glands secrete and why?
A alkaline fluid (calcium, citric acid and enymes) to neutralise acidity of the vagina
What is the function of the bulbourethal glands for semen production
Produce mucous secretion to lubricated and facilitate internal reproduction (think of pre cum)
What is the secondary (hormonal) function of the testes (other than sexual reproduction)? Name the hormone, where its produced and three things its responsible for
Secretes androgen hormone - the male sex hormone Its produced by interstitial cells in the testes called leydig cells Responsible for: Rapid body growth Development of the reproductive tract Sperm formation Lean body mass Sex drive Growth of horns
What hormone does the hypothalamus release and what does it stimulate?
• Hypothalamus releases Gonadotrophin Releasing Hormone (GnRH) this stimulates anterior pituitary gland to release Follicle Stimulating Hormone (FSH) and Luteinising Hormone (LH) which both act on testes.
What does follicle stimulating hormone and luteinising hormone stimulate?
• FSH develops seminiferous tubules (sertoli cells) and stimulates spermatogenesis
• LH causes interstitial cells (Leydig cells) to secrete testosterone
• Inhibin – hormone that inhibits FSH secretion at Ant Pituitary
• Testosterone: acts on hypothalamus and Ant pituitary to keep in normal range for reproduction
What does the female reproductive system produce and what does it do during pregnancy?
It produces oocytes (immature ova)
And it houses and nourishes embryo during pre-natal development (pregnancy)
What do oogonia do in the female reproductive system?
They form during embryonic development and develop into primary oocytes
What occurs to the oocytes during ovulation?
Oocytes splits into secondary oocytes and a polar body Then it developed and seperates from the follicle to be encapsulated in a layer of glycoproteins
How does ovulation actually occur with the oocytes?
The follicle secretes proteolytic enymes to break through the ovary wall and allows the secondary oocytes to escape
What occurs to the remainder follicle after ovulation?
Its developes into the corpus lutem- an endocrine gland
What is the structure of the uterus (womb)
It has a thick wall of smooth muscle and epithelial lining which crates the endometrium
What is the difference between the mensturation and ostreus cycle in mammals?
The endometrium is released in the menstral cycle, its reabsorbed by the uterus in other mammals