Chapter 16 Flashcards
HEREDITY
-passing genetic material from one generation to the next during sexual reproduction.
FERTILISATION
-fusion of the nucleus of egg cell -the nucleus of the sperm call to form a fertilized egg.
Where is the sperm produced from?
Testes in male
Where is the egg produced from?
Ovaries in female
What is fertillisation?
the fusuion of the nucleus of egg cell and and the nucleus of the sperm cell to form a fertillised egg
twice the number genetic materials as compared to the sex cells
When is the offspring (young) formed?
when nuclei of two sex cells- an egg cell and sperm cell fuse (join together)
After fertilization, what does the fertilized egg develop into?
- into an embryo and travel to the uterus to be implanted in it the uterine wall where it develops into a foetus
New individual
- contains DNA from both parents
- inherit characteristics from both parents and is genetically different from both parents
Define the word ‘heredity’
- process of passing genetic material from one generation to the next during sexual reproduction
How does the offspring receive genetic material?
- half- from mother (egg)
- half from daddy (sperm)
*This is a random process
Some disorders or diseases such as suckle cell/anemmia (blood disorder) are carried in genetic material and CAN be passed from parent to offspring
What is puberty?
- period where the body underegoes various physical changes and matures sexually
Begins- age 11 to 14
What is puberty caused by?
- caused by hormones produced by the body
Define hormones
- chemical substances that control and coordinate activites throught the body by triggering other organs to function
Hormones- found in very small quantitiesin the blood but have a huge effect on many organ systems
Name the 5 parts of the MALE reporductive system and their functions
1) Testis
- produces sperms
- produces male sex hormones that controls sexual development in the body
2) Sperm duct
- Carries sperms from the testes to urethra
3) Sex Glands
- Releases a slippery fluid that contains nutrients to nourish the sperms
- The white liquid mixture of fluid and sperms is called semen
4) Urethra
- A tube which allows sperms to pass through during ejaculation (process in which semen leaves the male reproductive system)
- Allows urine to be removed from the body
^ Note: urine and semen passes through the urethra but never at the same time
5) Penis
- Deposits semen into vagina during ejaculation
- During sexual intercourse penis becomes erect anf hard to enter the vagina and deposits the semen containing millions of sperms cells deep into the vagina (part of female reproductive system)
Name 6 parts of the FEMALE reroductive system and the functions of them
1) Ovary
- produces eggs
- produces female sex hormones that control sexual development in the body
2) Oviduct (fallopian tube)
- narrow muscular tube leading fro, ovary to the uterus
- Mature eggs are released from the ovary into the pviduct to be fertillised
- site of fertillisation
3) Uterus (womb)
- Muscular organ where a foetus develops during pregnancy
- It has elastic muscular walls to enable contraction to push out foetus during birth
4) Uterine lining
- the inner lining of the uterus which thickens to prepare for embryo implantation
- Uterine lining breaks down when no fertilisation occurs
5) Cervix
- Opening of the uterus
- Connects uterus to the vagina
- Has a circular ring of muscle at the lower end of uterus that could enlarge to allow the delivery of fetus
6) Vagina
- Where semen is deposited during sexual intercourse
- It leads from the cervix to the opening on the outside
What happens if fertilisation does not occur?
- The egg cell will disintegrate/breakdown and be released during menstruation
What happens during ovulation?
- an ovary releases a mature egg cell which enter the oviduct
During birth, why is there strong contractions of the uterus?
To push the baby past the cervix and out the mother’s body through the vagina
Unlike males, the urethra of femal performs only one function- to carry urine from the bladder to the outside of the body
NOTE: Urethra is not considered as part of the female reproductive system
What id the testes are unable to function?
Sperm will not be produced/are unhealthy
What if the oviducts are blocked?
Sperms and eggs cannot meet for fusion to occur, thus fertillisation cannot occur :(
What is menstruation?
process- linning of the uterus, blood vessels and the unfertillised egg cell breaks down and are discharged through the vagina
Menstruation occurs if fertillisation does not occur
What happens to the two ovaries upon purberty?
Take turns to release an egg cell once in about 28 days in prepapration for fertilisation
Upon successful fertilisation, what happens to the uterus?
- The lininng of the uterus thickens with blood vessels formed to receive a fertilised egg
What is menstrual cycle?
is a series of events that repeats itself in the female reproductive system every month
affected by stress, illness and diet
typical cycle- 28 days (counted from the first day of menstruation to the first day of the next)
why does mentrual cycle of a woman stop at age of 50?
ovary stop releasing egg cells
Day 1-5
- Menstruation occurs
- The duration of menstruation varies among individuals
Day 6 -9
- The lining on the wall of the uterus thicken, with many blood vessels formed in it
- This process prepares the uterus for the implantation of the embryo if fertillisation occurs
Day 10- 15
- One ovary will release an egg into the oviduct on around day 14
- This is known as: ovulation
- A woman is most fertile during this period and having sexual intercouse is likely result in pregnancy
Day 16- 28
- The uterine lining continues to thicken
- If no fertillisation occurs, menstruation will occur again after day 28
How long can an egg survive?
for 1 day after it is released from an ovary
How long can sperms survive?
- 3-5 days in the female reproductive system
Hence, if sexual intercouse took place on day 10, it is still possible to get pregnant (may be able to survive until day 14)
How long does it take for an embryo to grown into a foetus with developed organs?
- two months
What affects development of foetus?
- poor nutrition
- substance abuse (smoking/alcohol/drugs)
Effect of substance abuse on the foetus
- born premature- require intestive care- as organs may not be fully developed
- born with low birth weight- may have undeveloped immune systems and higher risk od getting infections
- smoking-affect development of foetus’ heart, lungs and brain-,may develop respiratory problems later in life,likely to face obesity and diabetes
- alcohol consumption and abuse of drugs- lead to physical/intellectual/behavioural challenges, find it difficult to pay attention and learn
What do birth control methods do?
- prevent pregnancy by disrupting certain processes and/or functions of human reproductive system:((
classified into 2 grps
- temporary (reversible)
- permanent (irreversible)
Name the 6 temporary birth control methods
1) Rhythm method (males/female)
- Do not engage in sexual intercourse during the time when woman is ovulation/during the fertile period of her menstrual cycle
- This method- can be unreliable and pregnency may still occur
2) Condom (males)
- rubber covering placed over the penis before sexual intercourse
- prevent sperm from entering the uterus
3) Spermicide (females/males)
- cream that kills sperms in the vagina
- used alone/with other methods of birth control
4) Inter- uterine Devive (IUD) (females)
- contains copper that is inserted into uterus by doctor
- prevents sperms from fertilling an egg
- prevents an embryo from being implanted in the uterus
- last- 3 to 10 years
5) Birth control pills
- contains sex hormones that disrupts the release of eggs from ovaries (prevents fertillisation from occuring)
6) Diaphragm (female)
- dome shaped plastic capp placed into the vagina to cover the cervix
- prevents sperms from entering the uterus and reaching the oviducts
Contraceptives not 100% effective
100% effective- abstinence
Name the 2 permenant birth control methods
1) Vasectomy (male)
- Sperms ducts are surgically cut and tied
- No sperms can reach the penis so no sperms released via ejaculation
- Sperms produced by the testes- broken down in the testes
2) Tubal ligation (female)
- Surgical tying and cutting of oviducts
- Egg released from ovaries cannot reach the oviduct to be fertilised by sperms
Contraceptives not 100% effective
100% effective- abstinence
What is not a form of birth control?
ABORTION as it is a DELIBERATE termination of pregnency
How is STI spread and what is the cause?
STI- Sexually transmitted infections
- mainly through sexual intercourse
- cause:
- bacteria/viruses
- transmitted from an infected person to an uninfected person via:
1) sharing of unsterilised/contiminated needles used by an infected person (during injection/pircing/tattooing)
2) from mother to an infant during childbirth/breast- feeding
3) Blood transfusion
Some STI diseases and their symptoms and possible long term effects
1) Syphilis (bacterial infection)
- symptoms: fever, headache weight loss
- possible long term effects: blindness/infertility/major brain damage
2) Gonorrhoea (bacterial infection)
- symptoms: buring sensation during urination/pain in lower abdomen
- possible long term effect: infertility/long- term pelvic/abodminal pain
3) Human Immunodeficiency Virus (HIV) (viral infection)
- symptoms: Flu- like symptoms like sore throat/fever
- possible long- term effects: death :) /development into AIDS if left untreated
What do antibiotics do?
- kill harmful bacteria/stop their growth
- treat- syphilis/gonorrhea
- NO EFFECT- viruses- HIV
What can help to prevent transmission of STIs?
- Condoms IF used correctly/consistently
- HOWEVER, may not completely effective
- best way to avoid transmitting/contracting- practice abstinence :(
What was the reason why there are more pople being born each year than dying?
1) Medical advancements
- New drugs/vaccines- helped people to survive and live longer live
- Vaccines- protect people against deadly diseases
2) Increase in food production
- With advancement in technology, plants- grown in soil that used to be infertile
- Crops- better protectedd from pests
- More food available to feed farmed animals- healthier with new drugs
- Good food=good health :)
3) Improved transportation
- Transportation via trian/ship/plane became more common
- Allowed goods (food/medicines) supplied to more regions in a shorter time
4) Improved sanitation
- Better sanitation and waste mangement reduced the spread of deadly diseases
- better protected- healthier societies
