Genetic Technology, Reproductive Biology and Genetics
- Explain the main components of male and female reproductive system.
- Explain the main reproductive hormones in female and describe their role in the menstrual cycle and pregnancy
- Compare the processes of mitosis and explain their significance.
- Define key terms in genetics and summarize the outcomes of simple monohybrid crosses.
- Predict the results of non-mendelian inheritance genetics problems.
- Name the main features of male and female reproductive systems and relate features to function
- Describe the functions of FSH, LH, progesterone and oestrone in controlling the menstrual cycle
- Apply knowledge to specific issues such as of hormones in fertility treatments (IVF) and use of hormones in contraceptives.
- Identify the different stages in the processes of mitosis from diagrams/photomicrographs
- Compare and contrast meiosis and explain the biological significance of the differences
- Describe and explain the significance of meiosis (reduction division) with reference to spermatogenesis and oogenesis.
- Define key terms such as dominant, recessive, homozygous, heterozygous, gene, allele, locus, phenotype, genotype.
- Predict the results from simple monohybrid crosses.
- Demonstrate use of non- mendelian inheritance mechanisms: gender; sex-linkage; incomplete/ co-dominance and multiple alleles (blood groups) in a range of contexts.
Read more about Mendelian Genetics – Introduction to Drosophila and Genetic
ACCESS HUMAN BIOLOGY DAYTIME / EVENING
HUMAN REPRODUCTION SUMMARY
1. Male reproductive system
2. Formation of gametes – spermatogenesis
3. Structure of the sperm
4. Microscopic structure of the testis (plural: testes)
5. Female reproductive system
6. Formation of the gametes: oogenesis
7. Microscopic structure of the ovary
8. Hormonal control of the female reproductive cycle (oestrus / menstrual cycle)
9. Fertilisation to implantation
10 Placenta
11 Birth and lactation
12 Use of hormones in IVF and contraception
Questions Criteria:
4.1 Name the main features of male and female reproductive systems and relate features to function.
5.1 Describe the functions of FSH, LH, progesterone and oestrogen in controlling the menstrual cycle.
5.2 Apply knowledge to specific issues such as use of hormones in infertility treatments (IVF) and use of hormones in contraceptives.
6.3 Describe and explain the significance of meiosis (reduction division) in achieving variation within species with additional reference to spermatogenesis and oogenesis.
Figure 1: Summary of gamete formation (Boyle & Senior (2002)
Figure 3: Male reproductive system
Figure 3: Section through a testis and process of spermatogenesis (Boyle & Senior (2002)
Figure 4
Female reproductive system
Figure 5 Structure of the ovary
Table 1: Events that occur during one oestrous cycle in which pregnancy does not occur. The arrows in the table show the sequence of these events (Baker & Rowland 2004)
| Stage | Hormonal Secretion | Events in the ovary | Events in endometrium |
| Follicular stage
Ovulation
Luteal Stage | FSH is released an stimulates the follicle
The cells in the outer region of the mature follicle secrete oestrogen
Once it reaches a particular concentration in the blood, oestrogen inhibits further secretion of FSH and stimulates the secretion and storage of LH by the pituitary
A surge occurs in the blood concentration of LH as stored LH is released by the pituitary
Cells in the corpus luteum secrete oestrogen and progesterone.
High concentrations of oestrogen and progesterone inhibit further release of LH and FSH | One or more follicles start to mature
An oocyte is released from one or more mature follicles
The empty follicle becomes a corpus luteum
Without LH and FSH the corpus luteum degenerates and stops the production of oestrogen and progesterone. |
Oestrogen stimulates an increase in the thickness of the endometrium and stimulates the development of more blood vessels.
Progesterone stimulates the endometrium to: · Grow thicker · Produce more blood vessels · Develop glands that secrete a nutritive fluid |
oestrogen
Figure 5:
Reproductive hormones
Write yourself a paragraph here about how the 4 hormones link together to cause the events in the ovary and the uterus (assuming no pregnancy)
Fig 7:
Fallopian tube and uterus following fertilization
)
Complete: Use of hormones in infertility treatments (IVF) and use of hormones in contraceptives.
| Contraception | IVF |
| What hormones are used typically? | What are the main hormonal causes of infertility in women? 1.
2. |
| How do they work in terms of preventing ovulation and fertilisation? | How can hormones be used to treat these forms of infertility? 1
2 |
Reproduction
Male Reproductive system
Objectives
To recap the main stages of meiosis and to recall their importance in terms of gamete formation and variation.
To name key parts of male reproductive structures
To describe their key functions
To relate structure to functions.
To identify structures from microscope slides.
A
B
C
D
E
F
Put the diagrams in order of events in meiosis
Name the different stages of meiosis
When finished, check with your partner
A
B
C
D
Describe the two important processes that you can see in this picture using your miniwhite board
Check with your partner as to the wording and how it can be improved
Extension question:
Name A – D
4.1 Name the main features of male and female reproductive systems and relate features to function.
Structure of male reproductive system
2
3
15
4
5
6
7
8
9
1
10
11
12
15
2
4
7
10
8
12
13
14
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6.3 Describe and explain the significance of meiosis (reduction division) in achieving variation within species with additional reference to spermatogenesis and oogenesis.
Spermatogenesis
Continues from puberty to old age
Stages:
Multiplication: mitosis
Growth: primary spermatocytes
Maturation: meiosis
2n
2n
2n
n
n
Female Reproductive System and Oogenesis: use booklet from previous lesson and blue sheet on process of meiosis
Objectives
Review the process of meiosis
Be able to describe the structures and functions of the female reproductive system.
Be able to understand the process of oogenesis and compare with spermatogenesis
Be able to recognize different components of the ovary from slides.
1: oviduct / fallopian tube
10: ovary
1a: fimbriae
6:vagina
6a vulva
9: uterus
9a cervix
Reminder: could get front or side view in exam. Must be able to label, and also describe some adaptations of system.
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1
10
1a
2
3
4
5
5a
6a
9
9a
8
6
7
Fallopian tube: where fertilization takes place; has cilia for moving egg; 1a fimbriae used to catch egg when released
Bladder
Pelvic bone
4 urethra
Don’t worry about or 5a
Vulva
6a vagina: acidic conditions here neutralized by alkaline sperm; smooth muscle
7 anus
8 anus
9a cervix
9 uterus or endometrial lining
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Shows ovaries attached by ligaments. Don’t necessarily release an egg each month, just depends on how developed they are.
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Picture of the Ovary
Summary of Differences between oogenesis and spermatogenesis: LEARN IT
Oogenesis
Only some cells that undergo multiplication will form oocytes the rest degenerate.
Amount of growth is greater.
First stage of meiosis completed before birth (stops at prophase 1)
Unequal divisions during meiosis results in polar bodies
Second division of meiosis will not finish until after fertilization (stops at metaphase II)
Spermatogenesis
All cells that undergo multiplication will form spermatocytes.
Amount of growth is less.
Both divisions of meiosis are completed after birth
Equal divisions at meiosis so no polar bodies.
Both stages completed from puberty
process of oogenesis: oocyte development in ovary
View the slides using microscopes
ovary of monkey – simulation of microscope
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Primary follicle
Mature (Graafian) follicle
Secondary
follicle
Recap process of meiosis first, highlighting need for genetic variation (crossing over in prophase 1 and independent assortment in metaphase 1).
Check they understand that when making eggs, only one becomes the primary follicle, the rest could either not develop or form polar bodies.
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Warning: graphic photos
Ovulation
Ovarian Cysts
Uterus
Cyst : 6 – 7 cm
Probe
Ovary
Fallopian tube
Endometriosis
Acute or chronic: cause is non specific infection.
Growth of endometrial tissues outside uterus, most commonly in ovaries, uterine tubes and other pelvic structures.
Tissue is responsive to hormone fluctuations so will bleed during cycle, into lower abdomen, causing ‘chocolate cysts.
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note the round structure projecting into the pelvic cavity, which is the folly catheter balloon within the bladder
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Objectives
Review the process of meiosis
Be able to describe the structures and functions of the female reproductive system.
Be able to understand the process of oogenesis and compare with spermatogenesis
Be able to recognize different components of the ovary from slides.
Break
Hormones that control fertility
Objectives
To describe the events of the oestrous cycle.
Name the key hormones and their main actions on the uterus and ovary.
Comparison of oogenesis and spermatogenesis
The Menstrual Cycle
This is when the lining of the uterus builds up and breaks down.
This is a cycle and is repeated roughly every 28 days.
This occurs from puberty to menopause.
NB you might get questions referring to the oestrus cycle – this is the same hormones but in other mammals, like cows, pigs and sheep
Oestrous relates to a cycle using the same hormones but refers to other mammals, like a cow, pig, sheep etc.
You may get asked questions relating to other mammals, principles are the same but the cycle might be a different length.
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Three functions
Maturation of the egg
Release of the egg so it can be fertilized
Development of a suitable environment for growth of the zygote (embryo)
FSH (1)
Oestrogen (2)
3
4
Animation of growth of follicles and ovulation
Multiple choice Quiz
Preparation for exam
Write yourself a paragraph on how all the hormones work (you can do this in your booklet under fig 5)
where they are made specifically
What effects they have on the ovary and the uterine wall (endometrium)
What effect they have on other hormones
Use other materials (e.g. video clips) to add to your class notes to learn material at a higher standard
Get it checked so that you are learning the right thing.
In the exam you might have to write a paragraph or interpret a graph
Controlling Reproduction in Humans
Treating Infertility
&
Avoiding Pregnancy
Objectives
Recap the function of the main hormones
Describe the hormones involved
Evaluate the effect they have on the process of ovulation
Review
In pairs discuss different forms of contraception, how they work, how effective they are; pros and cons
Link to different forms of contraception – downloads
Divided into
1) Methods with user failure
2) methods with no user failure
Contraceptive Pill
First introduced in 1951
Prevents ovulation
Used correctly over 99 % effective
Combined pill
Oestrogen and progesterone
Prevents release of both LH and FSH
Follicles do not develop in ovary each month
Ovulation does not occur
Pill taken daily for 21 days then
During 7 pill free days uterus lining breaks down
Mini Pill
Progesterone only
Mucus in cervix region thickens
Limits thickness of endometrium making it more difficult for implantation
Not very reliable at inhibiting ovulation
Treating Infertility
Affects 1 in 8 couples
It is a hormonal issue in 20 % of women who fail to conceive
To check female is ovulating which hormone would you check for?
Progesterone: this is released by corpus luteum.
Dept of Statistics: infertility in women
| Type | Tubal disease | Ovulatory disorder | Endome-triosis | Uter-ine | Multiple female factors | Male factor | Multiple female & male factors | Un-explained | Other |
| IVF | 3653 | 1970 | 1213 | * | 1031 | 2294 | 799 | 7970 | 8 |
| ICSI | 1171 | 910 | 474 | * | 326 | 12295 | 2852 | 4368 | * |
| Table 1: Percentage of couples seeking standard IVF or ICSI treatment by the reason they sought treatment (where a reason is recorded), 2011 ICSI: intracytoplasmic sperm injection |
If number is less than 5 it is obscured due to patient confidentiality.
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Treatment: Learn this!
Problem: Either produce too much oestrogen or too little FSH.
So: Synthetic anti oestrogen drug (e.g. Clomiphene)
Stimulates FSH and LH so removing inhibition by oestrogen.
Or given FSH / LH directly. More expensive as need to be purified from urine of postmenopausal women or produced by recombinant micro-organisms.
Check understanding
Look over exam questions on hormones
Read over relevant sections in Anatomy and Physiology textbooks and attempt questions.
Questions etc
Fill in the labels
Highlight which structure is responsible for producing sperm
Extension:
How is the male reproductive system adapted for producing and transferring sperm?
Testis
Cowper’s gland
A
B
C …
Useful to use for revision purposes later on
Fill in the labels
Highlight which structure is responsible for producing sperm
Extension:
How is the male reproductive system adapted for producing and transferring sperm?
Testis
Cowper’s gland
A
B
C …
Seminal vesicle
bladder
prostate
Vas deferens
urethra
penis
rectum
epididymis
testis
scrotum
prostate
See the notes sections for extra guidance for exam
Notes:
Producing: you should mention information on the scrotal sac, housing testes at lower temp to increase motility of sperm; use of glands (research each one separately) to produce semen containing mucus for lubrication, prostaglandins for peristalsis in female, fructose for energy, alkaline fluid to neutralize acidity in vagina.
Transferring: smooth muscle in vas deferens; blood and muscle in penis to make it erectile
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Label A, B, D, G, E, F What letter represents where fertilization takes place?
Useful to use for revision purposes later on
Answers Label A, B, D, G, E, F What letter represents where fertilization takes place?
See the notes section for answers
Ovary
Fallopian tube
Uterus
Endometrium
Cervix
Vagina
Watch spelling. B is where fertilization takes place (not fallopian tube – read the Q!)
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