What term is used for the time in young person’s life when second sexual characteristics take place?
Puberty
Name the hormone that maintains second sexual characteristics throughout the life of a male.
Testestorone
Where in the human female reproductive system does meiosis occur?
Ovary
Where in the human female reproductive system does the zygote formation occurs?
Fallopian tube
Where in the human female reproductive system does implantation occurs?
Endometrium
Describe the role of oestrogen in control of events of menstrual cycle.
Causes endometrium to thicken with blood
Describe the role of progesterone in control of events of menstrual cycle.
Prevents eggs from developing
By which type of cell division does the zygote divide?
Mitosis
Further divisions of zygote result in the formation of a morula. What is the next development stage after the morula?
Blastocyst
Give two roles of the placenta
Protects foetus
Materials (nutrients) move by diffusion and active transport, e.g. Glucose
Give change experienced by mother that indicates that birth process is starting
Cervix dilates (gets wider)
Contractions of the uterus
Give a short account of birth process.
1) Contractions of uterus begin and cervix dilates
2) baby’s head moves through cervix and down the birth canal (vagina)
3) Contractions of uterus expel the placenta
Name the three germ layers in the early human embryo
1- Ectoderm - on the outside gives rise to skin ,hair and nervous system
2- Mesoderm - in the middle gives rise to muscles and skeleton
3- Endoderm - on inside gives rise to lining of the digestive system
From which tissues does the placenta develop?
Uterine and embrionic tissue
What is amnion?
Amnion and chorion are membranes that surround the foetus.
They secrete amniotic fluid which protects the foetus.
What is semen?
Mixture of sperm cells and seminal fluids
State two secondary sexual characteristics of the human male.
- increased growth of penis
- shoulder broaden and muscles enlarge
Name a human female menstrual disorder in case of disorder give:
1) Possible cause
2) Method of treatment
1) Fibroids- uncertain but may be linked to levels of oestrogen/ hormonal imbalance
2) can be removed by surgery
Give an account of the importance of the placenta during human development in womb.
- antibodies can pass from mother to embryo to give passive acquired immunity
- placenta protects the embryo’s blood circulation from mother’s higher blood pressure
What is meant by in-vitro fertilisation?
IVF- involves removing eggs from an ovary and fertilising them outside the body
Explain the term MORULA.
Solid ball of cells formed from a zygote by mitosis
Explain the term BLASTOCYST
Hollow ball of cells formed from a morula
What happens in the ovary around day 14 of the cycle?
Ovulation/ release of the egg
Where is FSH produced?
Follicle stimulation hormone - secreted from the pituitary gland.
Give one function of FSH.
- stimulates Graafian follicle to secrete Oestrogen
- stimulates development of a new follicle
Give a cause of male infertility and suggest a corrective measure.d
low sperm count -> low levels of male hormone testestorone/ suffered from mumps in childhood
-> hormonal treatment or in-vitro fertilization
Where is testosterone secreted in the body of the human male?
Testes
Where are sperm produced
Testes
State two ways in which sperm differ from ova (eggs)
Egg is larger
Sperm has tail, egg doesn’t
Name gland that secretes seminal fluid
Prostate
State a function of seminal fluid
Enables sperms to move
What is meant by contraception?
Prevention of pregnancy
Give an example of a surgical method of male contraception.
Suggest advantage and disadvantage
Cutting of spurm ducts
-> 100% effective
But difficult to reverse
List three methods of contraception other than surgical.
Natural - no intercourse during time in menstrual cycle when pregnancy is likely
Chemical- spermicides kill sperm/ antibaby pill
Mechanical - physical barriers / condoms
In humans, widening of the female hips is one example of physical changes that distinguish the sexes but are not essential for reproduction.
what term is ment?
Second sexual characteristics
Which hormone in particular plays significant role in maintaining pregnancy? Where is it produced?
Progesteron/ placenta