topic 2: human reproduction
Reproduction is an essential process for the survival of a species. The functions of the reproductive systems are to produce reproductive cells, the gametes, and to prepare the gametes for fertilization. In addition, the male reproductive system delivers the gametes to the female reproductive tract. The female reproductive organs nourish the fertilized egg cell and provide an environment for its development into an embryo, a fetus, and a baby.
Human reproduction takes place by the coordination of the male and female reproductive systems. In humans, both males and females have evolved specialized organs and tissues that produce haploid cells, the sperm and the egg. These cells fuse to form a zygote that eventually develops into a growing fetus. A hormonal network is secreted that controls both the male and female reproductive systems and assists in the growth and development of the fetus and the birthing process.
Assessment Statements
Human reproduction takes place by the coordination of the male and female reproductive systems. In humans, both males and females have evolved specialized organs and tissues that produce haploid cells, the sperm and the egg. These cells fuse to form a zygote that eventually develops into a growing fetus. A hormonal network is secreted that controls both the male and female reproductive systems and assists in the growth and development of the fetus and the birthing process.
Assessment Statements
Compare sexual and asexual reproduction
Compare: Give an account of similarities and differences between two (or more) items, referring to both (all) of them throughout.
Compare: Give an account of similarities and differences between two (or more) items, referring to both (all) of them throughout.
While asexual reproduction only involves one organism, sexual reproduction requires both a male and a female. Some plants and unicellular organisms reproduce asexually. Most mammals and fish use sexual reproduction. Some organisms like corals and komodo dragons can reproduce either sexually or asexually. But in the long term (over several generations), lack of sexual reproduction compromises their ability to adapt to the environment because they do not benefit from the genetic variation introduced by sexual reproduction.
image from csls-text.c.u-tokyo.ac.jp
Describe the structure and explain the function of the male and female reproductive systems
Describe: Give a detailed account.
Describe: Give a detailed account.
Human reproduction employs internal fertilization, and depends on the integrated action of hormones, the nervous system, and the reproductive system. Gonads are sex organs that produce gametes. Male gonads are the testes, which produce sperm and male sex hormones. Female gonads are the ovaries, which produce eggs (ova) and female sex hormones.
Explain the roles of oestrogen and testosterone in the development of secondary sexual characteristics
Explain: Give a detailed account of causes, reasons or mechanisms.
Explain: Give a detailed account of causes, reasons or mechanisms.
Secondary sex characteristics begin at the onset of puberty in both men and women.
In males the primary sex hormone is Testosterone. This hormone is produced in the testis. Some of the secondary sex characteristics include;
In females the primary sex hormone is Oestrogen. This hormone is produced in the ovary. Some of the secondary sex characteristics include;
In males the primary sex hormone is Testosterone. This hormone is produced in the testis. Some of the secondary sex characteristics include;
- increased number of produced sperm cells
- growth and development of the sexual organs (penis and testis)
- development of body hair (pubic hair, armpit hair, facial hair)
- body mass will also increase (partly increase in muscle mass)
- voice breaking (sudden deepening of the voice)
- development of a sexual drive in behaviour.
In females the primary sex hormone is Oestrogen. This hormone is produced in the ovary. Some of the secondary sex characteristics include;
- beginning of the menstrual cycle (includes ovulation and menstrual period)
- development of body mass (rounding of body shape at hips)
- development of body hair (pubic hair, armpit hair)
- gradual deepening of voice (but no sudden breaking process)
- growth and development of sexual organs (larger breasts)
Outline the roles of oestrogen and progesterone in the menstrual cycle
Outline: Give a brief account or summary.
Outline: Give a brief account or summary.
The menstrual cycle in women is a recurring process in which the lining of the uterus - womb - is prepared for pregnancy, and if pregnancy does not happen, the lining is shed at menstruation.Several hormones control this cycle, which includes controlling the release of an egg each month from an ovary, and changing the thickness of the uterus lining. These hormones are secreted by the ovaries and pituitary gland.
FSH
The hormone FSH is secreted by the pituitary gland. FSH makes two things happen:
OestrogenThe hormone oestrogen is secreted by the ovaries. Oestrogen makes two things happen:
LH
The hormone LH causes the mature egg to be released from the ovary.
This image shows how the level of oestrogen changes during the menstrual cycle. Progesterone is another hormone secreted by ovaries: it maintains the lining of the uterus and stays high during pregnancy
FSH
The hormone FSH is secreted by the pituitary gland. FSH makes two things happen:
- it causes an egg to mature in an ovary
- it stimulates the ovaries to release the hormone oestrogen
OestrogenThe hormone oestrogen is secreted by the ovaries. Oestrogen makes two things happen:
- it stops FSH being produced - so that only one egg matures in a cycle
- it stimulates the pituitary gland to release the hormone LH
LH
The hormone LH causes the mature egg to be released from the ovary.
This image shows how the level of oestrogen changes during the menstrual cycle. Progesterone is another hormone secreted by ovaries: it maintains the lining of the uterus and stays high during pregnancy
Describe the stages of the developing feotus
Describe: Give a detailed account.
Describe: Give a detailed account.
Describe the role of the placenta in the nutrition of the developing embryo
Describe: Give a detailed account.
Describe: Give a detailed account.
The placenta plays a key role in the nutrition of the fetus. It mediates the active transport of nutrients and metabolic wastes across the barrier separating maternal and fetal compartments, as well as modifying the composition of some nutrients through its own metabolic activity. The function of the placenta is essential to the growth of a healthy fetus; it is becoming apparent that the activities of the placenta are in turn modulated by signals originating from the fetus.
Describe how the developing embryo is protected by amniotic fluid.
Describe: Give a detailed account.
Describe: Give a detailed account.
image from www.howitworksdaily.com
The amniotic fluid has many purposes. It helps to cushion hard blows and jolts to the abdomen. It allows freedom for movement while permitting symmetrical musculoskeletal development. It also maintains a constant body temperature.
It also allows for lung development as the baby begins to breathe amniotic fluid to strengthen its lungs and swallow fluid.
It also allows for lung development as the baby begins to breathe amniotic fluid to strengthen its lungs and swallow fluid.
Evaluate the effectiveness of different methods of contraception
Make an appraisal by weighing up the strengths and limitations
Make an appraisal by weighing up the strengths and limitations
Analyse some of the moral and ethical questions posed by in vitro fertilization and artificial insemination by donors.
Analyse: Break down in order to bring out the essential elements or structure. To identify parts and relationships, and to interpret information to reach conclusions
Analyse: Break down in order to bring out the essential elements or structure. To identify parts and relationships, and to interpret information to reach conclusions
The term in vitro means 'in glass' and is used to describe a procedure that takes place outside the human body in some form of laboratory glassware. In in vitro fertilization, an ovum is fertilized outside a woman's body in a special dis. The fertilized ovum is placed in the woman's uterus to develop. This procedure is used to treat couples who are unable to conceive. However, there various issues associated with IVF. Debates on IVF are clouded by different ethical value systems and deep prejudices. Decision makers, medical practitioners, scientists, courts, and the public in general are facing new quandaries that involve controversies among profoundly held values.
Key Terms
|
asexual
stolen plantlets sexual reproduction mitosis meiosis parent cell daughter cell homologous reduction division haploid flagellum offspring |
vegetative
runner tissue culture embryo gamete ejaculate semen sexual intercourse afterbirth puberty luteinising hormone menstrual cycle external fertilisation |
tuber
binary fission zygote embryo fertilisation identical twins stem cell implant fallopian tube ciliated cells oestrogen progesterone penis |
fission
fragmentation twins fraternal twins clone sperm uterus cervix vagina scrotum period follicle epiditimus |
budding
cuttings ovum testes ovaries internal fertilisation seminal vesicle prostate vas deferins testosterone ovulation corpus luteum |
Class Material
Sexual and Asexual Reproduction
Sexual and Asexual Study Guide
Asexual Reproduction video worksheet
Investigating Reproductive Strategies activity
Sexual and Asexual Reproduction
Sexual and Asexual Study Guide
Asexual Reproduction video worksheet
Investigating Reproductive Strategies activity
Part 1 Asexual and Sexual Reproduction
Human Reproduction
Human Reproductive System (study guide)
Why Sex video worksheet
Human Reproduction Stop and Think activity
Menstrual Cycle Graphing activity
Great Sperm Race Worksheet
Life's Greatest Miracle worksheet
How Ultrasound Changed The World of Sex article
From Delivering Limbs article
In-vitro Fertilization Fact Sheet
In-vitro Fertilization Family Cards activity
Contraception (ppt)
Contraception Methods worksheet
TOK - When is it immoral to have children?
Caesarean births 'affecting human evolution' - BBC Dec 2016
Part 2 Human Reproductive System Anatomy
Part 3 Reproductive Hormones
Part 4 Female Menstural Cycle
Part 6 Copulation, Fertilisation and Conception
Part 7 Pregnancy and Development
Useful Links
Quizlet Study Guide: Asexual Reproduction
Quizlet Study Set: Reproduction
Quizlet Study Set: Human Reproduction
Quizlet Study Set: Fetal Development
Quizlet Study Set: Contraception
Sexual and Asexual Reproduction
Check out this video clip on Asexual reproduction
Asexual Reproduction
Asexual vs Sexual Reproduction
Human Reproduction
BBC Bitesize Reproduction
Check out this interesting video clip on Mate Choice
BBC Bitesize Sex Hormones
Male Reproductive System
Female Reproductive System
Menstruation
Menstruation Cycle Animation and Quiz
In-vitro Fertilization ethics
BBC Bitesize IVF
Videos
Quizlet Study Guide: Asexual Reproduction
Quizlet Study Set: Reproduction
Quizlet Study Set: Human Reproduction
Quizlet Study Set: Fetal Development
Quizlet Study Set: Contraception
Sexual and Asexual Reproduction
Check out this video clip on Asexual reproduction
Asexual Reproduction
Asexual vs Sexual Reproduction
Human Reproduction
BBC Bitesize Reproduction
Check out this interesting video clip on Mate Choice
BBC Bitesize Sex Hormones
Male Reproductive System
Female Reproductive System
Menstruation
Menstruation Cycle Animation and Quiz
In-vitro Fertilization ethics
BBC Bitesize IVF
Videos
Asexual Reproduction
Hank gets into why sex is the preferred method of reproduction for most species - and it's not for the reasons you're thinking.
Evolution - Why Sex? - PBS/Nova Documentary
David Puts discusses the evolution of human mating and reproduction, illustrating how evolutionary biology can help us understand ourselves and each other. Topics include how people compete for and choose mates, men's care for their children, infidelity, and women's orgasms (This talk describes explicit sexual content and contains graphic images)
Paul Andersen starts with a brief description of asexual and sexual reproduction. He explains how meiosis ensures variation in the next generation. He describes the important structures in the male and female reproductive system. He explains how the menstrual cycle ensure the success of the released ovum. He also shows how a zygote becomes a blastula, gastrula, embryo and fetus.
Hank lets us in on the meaning of life, at least from a biological perspective - it's reproduction, which answers the essential question of all organisms: how do I make more of myself? So, sex, how does it work?
An informative video of the biological processes behind the menstrual cycle.
The Great Sperm Race (Documentary Film 2009). With 250 million competitors, it is the most extreme race on earth and there can only be one winner.
Image-maker Alexander Tsiaras shares a powerful medical visualization, showing human development from conception to birth and beyond.
NOVA presents the first film ever made of the incredible chain of events which turns a sperm and an egg into a newborn baby. Amazing photographic techniques give the viewers the feeling of being reduced to the size of cells, following the sperm on its perilous voyage toward the egg, and meeting protectors and enemies along the way—like Ulysses on a microscopic odyssey.
This is a beautiful medical animation about IVF (In Vitro Fertilization)
Infertility affects 1 in 8 couples worldwide. But in the last 40 years, more than 5 million babies have been born using in vitro fertilization (IVF). How does it work? Nassim Assefi and Brian A. Levine detail the science behind making a baby in a lab.
Gym teacher Hank gives us the full story of the past, present, and future of birth control.
