Part of The Student Room Group

  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

IB Biology Syllabus Notes

Extracts from this document...

Introduction

6.6.1 Draw and label diagrams of the adult male and female reproductive systems. Male Female 6.6.2 Outline the role of hormones in the menstrual cycle, including FSH (follicle stimulating hormones), LH (luteinizing hormone), estrogen and progesterone. The menstrual cycle: 0. FSH is secreted by the pituitary gland and its levels start to rise. This stimulates the follicle to develop and the follicle cells to secret estrogen. 0. Estrogen then causes the follicle cells to make more FSH receptors so that these can respond more strongly to the FSH. 0. This is positive feedback and causes the estrogen levels to increase and stimulate the thickening of the endometrium (uterus lining). 0. Estrogen levels increase to a peak and by doing so it stimulates LH secretion from the pituitary gland. 0. LH then increases to its peak and causes ovulation (release of egg from the follicle). ...read more.

Middle

a) Follicle Stimulating Hormone (FSH) is secreted by the pituitary gland of the brain and stimulates the development of a primary follicle. b) Primary follicle cells secrete estrogen which in turn increases the secretion of FSH in a positive feedback. c) The estrogen thickens the lining of the uterus in preparation for a fertilized egg. d) The peak of estrogen secretion at day 12 causes the pituitary to release a surge of LH. This loosens the now mature egg which is released in ovulation: I. LH reduces the secretion of Estrogen II. LH stimulates the empty follicle to develop into the corpus luteum a) Progesterone and estrogen together stop any more LH and FSH being secreted from the pituitary. (negative feedback) b) Progesterone maintains the lining of the thickened endometrium in preparation for the implantation of a fertilized egg. ...read more.

Conclusion

is injected 36 hours before the collection of the eggs. HCG loosens the eggs in the follicles and makes them mature. 0. The man needs to ejaculate into a jar so that sperm can be collected from the semen. The sperm are processed to concentrate the healthiest ones. 0. A device that is inserted through the wall of the vagina is used to extract the eggs from the follicles. 0. Each egg is then mixed with sperm in a shallow dish. The dishes are then put into an incubator overnight. 0. The next day the dishes are looked at to see if fertilization has happened. 0. If fertilization has been successful, two or three of the embryos are chosen to be placed in the uterus by the use of a long plastic tube. 0. A pregnancy test is done a few weeks later to find out if any of the embryos have implanted. A scan is done a few weeks later to find out if the pregnancy is progressing normally. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

or


Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Biology essays

  1. : Hormone Levels During the Menstrual Cycle

    f) Describe changes in temperature before and during ovulation. The temperature slowly decreases before ovulation and reaches a high point at ovulation then starts to decrease again.

  2. Genetics NOTES

    and I(O) in which A & B are dominant over O. - Discontinuous variation involves sharply defined characteristics such as left or right handedness, whereas continuous variation is the more complex variation, involving a wide range of characteristics to be chosen such as.

  1. IB Genetic Unit Notes

    Telophase I Nuclear membrane re-forms around the daughter nuclei. The chromosome number has been halved. The chromosomes start to decondense. There is NO interphase between Meiosis I and Meiosis II Phase Description Picture Prophase II The chromosome condense and the centrioles duplicate Metaphase II The nuclear membrane breaks down and the spindle forms.

  2. IB Biology notes on infection and the body's responses.

    Protective Proteins a. complement proteins are plasma proteins that complement certain immune responses. i. may amplify an inflammatory reaction, bind to antigens to make them more recognizable, make holes in the walls and cell membranes of bacteria b. interferons are proteins produced by virus-infected cells i.

  1. Experimental Design Notes

    Finds the difference between largest and smallest value o Standard Deviation: measure of how a data set is spread out around the mean * o Error bars: graphical representation of the variability of data o Can be used to show range of data or standard deviation o In normal distribution

  2. Environmental systems revision notes

    Resources Natural capital: resources that nature gives you, reserves. It is not manufactured. (Trees, living organisms). Natural income: it is what we can get from natural capital. (Fresh water, wood, food,). Types of natural capital: Renewable: can replece themselves usually with the sun as source of energy, but can disappear if not harvested sustainable.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work