What is one function of amniotic fluid?
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It acts as a shock-absorber, protecting the embryo from mechanical injury.
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What is one function of amniotic fluid?
It acts as a shock-absorber, protecting the embryo from mechanical injury.
What are the two main functions of the ovaries in the female reproductive system?
To produce ova (female gametes) and female sex hormones.
What are the two main components of the male reproductive system?
Testes and male sex hormones.
How does amniotic fluid prevent desiccation?
It prevents the embryo from drying out.
What are the oviducts and their role in the female reproductive system?
Thin-walled muscular tubes that transport the ovum and where fertilization usually occurs.
When is menstruation likely to have occurred?
From the 1st to 5th day.
What is the function of the testes?
To produce sperms (male gametes) and male sex hormones.
What stable environment does amniotic fluid provide for the embryo?
It provides a constant temperature and pH.
What structure secretes male sex hormones?
Structure 4.
How do the cilia in the oviducts assist in the movement of the ovum?
The beating action of cilia and wave-like muscular contractions move the ovum along the tube.
On which day is ovulation most likely to have occurred?
Around the 14th day.
What is the role of the scrotum in the male reproductive system?
To keep the temperature slightly lower than body temperature for proper sperm development.
What is the gestation period in humans?
About 38 weeks from fertilization to birth.
How is sperm transferred from a male to a female during reproduction?
Through sexual intercourse or copulation.
What was the world population in December 2017?
7.6 billion.
What are the three parts of the ducts that store and transfer sperm?
Epididymis, sperm duct (vas deferens), and urethra.
What role does amniotic fluid play during childbirth?
It helps lubricate the birth canal.
What is the function of the uterus?
To provide a site for embryo attachment and to accommodate the developing fetus during pregnancy.
What structure secretes seminal fluid?
Structure 2.
What is ovulation?
The release of an ovum from the ovary.
Why is a lower temperature essential for sperm development?
Because it is necessary for sperms to develop properly.
What happens to the embryo about eight weeks after fertilization?
It becomes a foetus with all major organs formed.
Which contraceptive methods prevent sperm from reaching an ovum?
Using a condom, diaphragm, and intrauterine device.
What happens to the penis during sexual stimulation?
It becomes hard and rigid due to increased blood flow.
What are the seminiferous tubules?
Highly coiled tubules in the testis that are the site of sperm production.
What is the process called when the nucleus of a sperm fuses with the nucleus of an ovum?
Fertilization.
What does the United Nations estimate the world population will reach by 2040?
10 billion.
What is the function of the epididymis?
It stores sperm temporarily and allows sperm to mature.
What is the placenta?
A disc-like organ formed at the site of implantation.
What is the function of the acrosome in a sperm cell?
It contains enzymes that help the sperm penetrate an ovum.
What is the uterine lining?
The soft, smooth inner lining of the uterus where the embryo attaches.
Which structures have a similar function?
Structures 1 and P.
Where are the testes located?
In the scrotum, which hangs outside the abdominal cavity.
What is the cycle of building up and breakdown of the uterine lining called?
The menstrual cycle.
Where does the foetus grow and develop?
In the mother’s uterus.
What happens to ovulation if both oviducts of a woman are tied and cut?
Ovulation is not affected.
What is ejaculation?
The discharge of semen through the penis.
What hormone is produced between the seminiferous tubules?
Male sex hormones, such as testosterone.
What is a diaphragm in the context of birth control?
A dome-shaped rubber cap with an elastic rim that fits over the cervix to prevent sperm from entering the uterus.
Where does fertilization usually take place?
In the oviducts.
What is one way to slow down human population growth?
Birth control.
What is the role of the sperm duct (vas deferens)?
It transfers sperm from the epididymis to the urethra.
What are villi?
Finger-like projections that grow from the embryo and contain its capillaries.
What is packed in the midpiece of a sperm cell?
Mitochondria, which supply energy for the movements of the tail.
Which is larger in size: human sperm or human ovum?
Human ovum is larger in size.
What structures should be identified in the male rat's reproductive system?
Testes, epididymis, sperm ducts, prostate gland, and penis.
What is the cervix?
The lower end of the uterus that has a ring of muscle.
What happens from Day 1 to 5 of the menstrual cycle?
Menstruation occurs.
What are sperms?
The male gametes produced by the testes.
Where are male gametes (sperms) produced in humans?
In the seminiferous tubules of the testes.
What occurs on Day 14 of the menstrual cycle?
Ovulation, where the mature follicle ruptures and releases an ovum into the oviduct.
What connects the embryo to the placenta?
The umbilical cord.
What is the size of the foetus at around 8 weeks?
Approximately 3 cm.
What is the biological principle of contraceptive pills?
They contain synthetic sex hormones that prevent ovulation.
Where are sperms usually ejaculated during sexual intercourse?
At the top of the vagina near the cervix.
What role do male sex hormones play during puberty?
They promote the development of secondary sexual characteristics.
What are the main events involved in the birth process?
Rhythmic contractions of the uterine muscles, dilation of the cervix, breaking of amnion, expulsion of the foetus, and expulsion of the placenta.
How long must a diaphragm be left in place after intercourse?
Six to eight hours.
What happens to the jelly coat of the ovum once a sperm penetrates it?
It changes to prevent other sperms from entering.
What is family planning?
The idea of planning for an ideal family size and deciding not to have many children.
On which dates was menstruation occurring?
10th to 15th April (or 6th to 11th May) because there is a great drop in the thickness of the uterine lining during this period.
What does the urethra carry out of the body?
Semen and urine.
Why is it important for the embryo's blood to be separated from the maternal blood?
To prevent clumping of incompatible blood groups and protect the embryo from high maternal blood pressure and pathogens.
What is the role of the tail in a sperm cell?
It propels the sperm forward.
What structures should be identified in the female rat's reproductive system?
Ovary, oviducts, uterus, and vagina.
What is the role of the vagina in the female reproductive system?
It receives the penis during sexual intercourse and serves as the birth canal.
Which contains a nucleus: sperm or ovum?
Ovum contains a nucleus.
What occurs from Day 6 to 13 of the menstrual cycle?
Repairing of the uterine lining.
What is the shape of sperms?
Tadpole-like.
What happens to the uterine lining from Day 15 to 28?
The uterine lining further thickens and is prepared to receive an embryo.
What does the rhythm method involve?
Avoiding sexual intercourse during the fertile period.
What does the umbilical vein carry?
Oxygenated blood and nutrients from the placenta to the embryo.
What is the size of the foetus at around 12 weeks?
Approximately 10 cm.
Where are newly formed sperms stored temporarily?
In the epididymis.
What is the failure rate of contraceptive pills?
5%.
What challenges do sperms face in reaching the oviducts?
Some are trapped by mucus, killed by acidic secretion, or are defective and immotile.
What is parental care?
The care provided by parents, including food, clothes, shelter, and teaching language and basic skills.
What is the failure rate of using a diaphragm for birth control?
About 10%.
What is formed when the sperm nucleus fuses with the ovum nucleus?
A zygote.
What does contraception mean?
The prevention of pregnancy.
What are the three sets of accessory glands in the male reproductive system?
Seminal vesicles, prostate gland, and Cowper’s glands.
What period should the woman have sexual intercourse to get pregnant?
22nd to 24th April, as ovulation occurs within this time period, allowing for potential fertilization.
What happens to potential ova before a baby girl is born?
Thousands of potential ova are already present in her ovaries but remain immature until puberty.
What is the process called when the embryo embeds itself in the uterine lining?
Implantation.
What tissues compose the placenta?
Tissues from both the mother and the embryo.
What is the first step in examining the reproductive system of dissected rats?
Examine the reproductive system of a dissected male rat.
Which can move by itself: sperm or ovum?
Sperm can move by itself.
What is the failure rate of the IUD?
About 1%.
What happens from Day 15 to 28 of the menstrual cycle?
Further thickening of the uterine lining.
How do barrier methods like condoms and diaphragms work?
They trap semen and prevent sperm from entering the uterus.
What occurs if fertilization does not happen after ovulation?
The uterine lining breaks down and a new cycle begins.
What are the three parts of a sperm?
Head, midpiece, and tail.
What is the size of the foetus at around 20 weeks?
Approximately 20 cm.
How many sperms can a healthy man produce daily?
More than 100 million sperms.
What do the umbilical arteries carry?
Deoxygenated blood and waste products from the embryo to the placenta.
Where does fertilization typically occur in the female reproductive system?
In the oviduct.
What is breast-feeding?
The feeding of an infant or young child with breast milk.
What are some side effects of contraceptive pills?
Nausea, weight gain, headache, and high blood pressure.
What creates a current to suck the ovum into the oviduct?
The beating action of cilia lining the oviduct.
What are the biological principles of contraceptive methods?
Preventing ovulation, preventing sperm from reaching an ovum, and preventing the implantation of an embryo.
What surrounds each immature ovum in the ovaries?
Follicle cells, forming a follicle.
What is sterilization in the context of birth control?
A surgical method to prevent pregnancy with a failure rate of less than 1%, often irreversible.
How long after fertilization does implantation occur?
Around seven days.
What is released from the acrosomes of sperm to help penetrate the ovum?
Enzymes.
Why is the uterine lining thick during the period of 22nd to 24th April?
The uterine lining is thick during this period, ready for the implantation of the embryo.
What is the function of seminal fluid?
It nourishes sperm, provides a medium for swimming, and neutralizes vaginal acidity.
What safety precautions should be taken during the examination?
Cover any wounds with sterile dressings and wear disposable gloves.
Can the IUD be removed if a woman wants to become pregnant?
Yes, it can be removed by a doctor.
What is the purpose of surgical methods like vasectomy and tubal ligation?
To prevent sperm or ova from passing through and meeting.
What is the size of the foetus at around 38 weeks?
Approximately 36 cm.
How often is one mature ovum released from the ovaries?
Each month.
What materials diffuse from maternal blood into the embryo's blood?
Nutrients, oxygen, and antibodies.
What happens to the uterine lining if fertilization occurs?
The uterine lining does not break down and menstruation will only occur after the birth of the baby.
Why is the vaginal secretion important during reproduction?
It contains acid that helps slow down the growth of microorganisms.
What are the three distinct regions of a sperm?
The head, midpiece, and tail.
What happens to mammary glands during pregnancy?
They enlarge and become able to produce milk.
What should a woman do before starting contraceptive pills?
Consult a doctor and have regular check-ups.
How often does ovulation occur in females?
Approximately every 28 days.
What is formed by some cells of the embryo as it develops in the uterus?
The amnion.
What should be done after examining the reproductive systems of dissected rats?
Draw labelled diagrams of the reproductive systems.
Will tubal ligation affect a woman's secondary sexual characteristics?
No, her secondary sexual characteristics will not be affected because female sex hormones can still be produced by the ovaries.
What happens to the penis during sexual stimulation?
It becomes erect to allow for sexual intercourse.
What are some side effects of the IUD?
Irritation of the uterine lining, heavy menstruation, and painful cramps.
What is a vasectomy?
A surgical operation in which both sperm ducts of a man are tied and cut.
How do contraceptive pills work?
They contain synthetic female sex hormones that prevent follicles from developing in the ovaries, stopping ovulation.
What occurs during sexual intercourse in relation to fertilization?
Sperms are transferred through a male’s penis into a female's vagina.
What triggers the development of follicles and immature ova at puberty?
The secretion of female sex hormones.
What is the shape of an ovum?
Spherical.
What metabolic wastes diffuse from the embryo into maternal blood?
Urea and carbon dioxide.
What is the function of an intrauterine device (IUD)?
It prevents the embryo from implanting in the uterine lining.
What is menarche?
A woman's first menstruation, usually occurring around the age of 11.
What is the pathway of sperm after ejaculation?
Sperms swim through the cervix into the uterus and then to the oviducts.
What is lactation?
The process of producing and releasing milk when a baby sucks the nipples.
What is the rhythm method commonly known as?
The ‘safe-period’ method.
What happens to the follicle after it releases an ovum?
It becomes the yellow body.
What is the approximate length of a sperm?
About 0.06 mm.
How are female sex hormones transported to target organs after tubal ligation?
They are transported by blood to the target organs to carry out their functions.
What is the space between the amnion and the embryo called?
Amniotic cavity.
What activity involves examining human reproductive systems?
Examination of the male and female reproductive systems of humans using models.
What structures are involved in the female reproductive system?
Ovary, vagina, uterine wall, uterine lining, cervix, and oviduct.
What must individuals consider before undergoing sterilization?
They must be sure that they do not want babies in the future.
What position does the fetus change to a few weeks before birth?
Head downwards just above the cervix.
What happens if no ovum is released?
No fertilization can take place after sexual intercourse.
What happens to the remaining sperms after one sperm penetrates the ovum?
They soon die.
How many mature ova are typically released during a female's lifetime?
About 500.
Why are regular medical check-ups needed for IUD users?
To ensure the device remains in place.
What substances diffuse from maternal blood to foetal blood through structure X?
Antibodies and glucose.
What adaptations does the placenta have to facilitate material exchange?
Numerous villi for surface area, close proximity of blood, and a rich supply of blood vessels.
What is menopause?
The time when a woman's ovaries stop releasing ova and menstruation ceases, typically occurring between ages 45 to 55.
How does the size of an ovum compare to that of a sperm?
An ovum is much larger than a sperm.
What are the benefits of breast-feeding for babies?
Breast milk contains essential nutrients and antibodies that help protect against infectious diseases.
What occurs if the released ovum is not fertilized?
The yellow body degenerates.
How does the rhythm method work?
By avoiding sexual intercourse for several days around the time of ovulation.
How many embryos typically develop in a human pregnancy?
Usually only one embryo develops.
What process stimulates sperm production starting from puberty?
Meiotic cell division.
What is the importance of prenatal care?
It helps reduce the risk of many birth defects.
How can one estimate the time of ovulation?
By counting 14 days backwards from the first day of menstruation of the next cycle.
What fills the amniotic cavity?
Amniotic fluid.
What should be indicated in the photographs of human reproductive systems?
Structures that produce gametes and sex hormones, and where fertilization usually takes place.
What is the sequence of events leading to the birth of a baby called?
Labour (childbirth).
What is the purpose of emergency contraceptive pills (ECPs)?
To avoid unwanted pregnancy within 120 hours after sexual intercourse.
What is often used together with a diaphragm for increased effectiveness?
A spermicide.
Which of the following is not a function of fluid Y?
To provide oxygen to the foetus.
What are the components of an ovum?
Cell membrane, jelly coat, cytoplasm with yolk, and a nucleus.
How does the placenta maintain a steep concentration gradient?
By allowing efficient transport of materials away from the placenta.
What is the relationship between the events in the ovaries and the uterine lining?
The thickness of the uterine lining changes in response to the events occurring in the ovaries throughout the menstrual cycle.
How does breast-feeding benefit mothers?
It helps the mother recover from childbirth and may reduce the risk of breast and ovarian cancers.
What prepares the uterine lining to receive an embryo?
The thickening and sponginess of the uterine lining, supplied with blood vessels.
What is the fertile period?
The five days before and two days after ovulation.
What happens to sperms in the epididymis?
They mature and become motile.
What are the two types of twins?
Identical twins and fraternal twins.
What should women include in their diet during pregnancy?
A balanced diet with enough iron and folic acid.
What aids the zygote in traveling to the uterus?
The beating action of cilia and muscular contractions of the oviduct.
What is the purpose of the mini lab activity?
To examine the structure of the reproductive system in human models.
What happens to the muscles of the uterus when labour begins?
They contract regularly.
How do ECPs work?
They contain synthetic hormones that either stop or delay ovulation.
What are the side effects of using a diaphragm?
It has no side effects.
What is implantation?
The embedding of the embryo into the uterine lining.
What does the cytoplasm of an ovum contain?
Food reserves (yolk) for the developing embryo.
Why is breast milk easy for babies to digest?
Because the protein in breast milk is easy for babies to digest and absorb.
What hormones does the placenta secrete?
Hormones that help maintain the uterine lining throughout pregnancy.
What is the cycle of building up and breaking down the uterine lining called?
The menstrual cycle.
How long can an ovum survive after being released?
12 to 24 hours.
How are identical twins formed?
From a single zygote that divides into two separate cells, each growing into an embryo.
Why is iron important during pregnancy?
It is needed for the formation of foetal red blood cells.
What is the ball of cells formed after repeated mitotic divisions of the zygote called?
Embryo.
What is tubal ligation?
A surgical operation in which both oviducts of a woman are tied and cut.
When should ECPs be used?
As emergency contraception or in case of contraceptive accidents.
What is the first stage of labour?
Dilation of the cervix.
What is the role of the amnion?
To enclose the embryo and bathe it in amniotic fluid.
What occurs during Days 1 to 5 of the menstrual cycle?
Menstruation, where the thickened uterine lining breaks down and is expelled as menstrual blood.
What type of movement do ova exhibit?
Ova are not motile.
What is the failure rate of the rhythm method in birth control?
About 25%.
What happens to the uterine lining if fertilization does not occur?
It breaks down.
How long can some sperms survive in the female reproductive tract?
Up to five days.
What is the genetic relationship between identical twins?
They are genetically identical.
What does folic acid do during pregnancy?
It lowers the risk of some birth defects.
What marks the start of pregnancy?
Implantation.
What happens to sperm production after a male undergoes a vasectomy?
The testes can still make sperm and male sex hormones, but there are no sperm in the semen.
What must be done before taking ECPs?
They must be prescribed by doctors.
