Biology Week 29 - Human Reproduction

Day 1 | Day 2 | Day 3 | Day 4 | Day 5 - 6

Menstrual cycle FSH Estrogen LH Progesterone Menstruation Egg cell	Sperm cell Fertilization Fallopian tubes Fraternal twins Identical twins Conjoined twins Implantation Blastocyst	Placenta Gastrulation Gestation period Pregnancy Puberty Contraception STD

Which type of twins must always be the same sex?

Read standardized test practice passage #6 and answer the nine questions.
You have twelve minutes to complete the assignment.

Day 1 Assignment/lab - Reproduction
This assignment must be completed by the beginning of class tomorrow to receive credit.

1. Use Microsoft Excel to graph this hormone data.
2. Be sure to keep the criteria on this rubric in mind when making your graph.
3. Save the file on your computer.

More work will be done with this graph tomorrow.
Be ready to show the graph to your science facilitator on your computer.

If you complete the assignment in class today, surf these reproduction websites.

Day 2

Does the female body produce the hormone testosterone?

The Menstrual Cycle: This 28 day cycle controls human reproduction. The cycle is controlled by 4 major hormones. FSH - follicle-stimulating hormone from the pituitary gland. Estrogen from the ovaries. LH - luteinizing hormone from the pituitary gland. Progesterone from the ovaries. Significant events on the graph: Menstruation Peak of female hormone drive Causes maturation of the egg Ovulation Institutes a break-down of the uterine lining The average cycle is 28 days. Normal menstrual cycles may vary in length from 26-35 days.

Click to enlarge the graph

The first thing a developing embryo must do is block the break-down of the lining. Immediately after implantation, the embryo produces large amounts of the hormone HCG to maintain the uterine wall lining. A home pregnancy test kit works by detecting HCG.

Day 2 Assignment/lab - Reproduction
This assignment must be turned in by the end of class today to receive credit.

1. Add a description of each of the 5 significant events to your Excel graph.
2. Before printing, check your graph against the Microsoft Excel graph evaluation rubric.
3. Fix any weaknesses identified by the rubric, then print the graph.

Turn in the completed graph and evaluation rubric. Remember to place the rubric on top.

Day 3

How long is a human pregnancy?

Life of the egg cell:

• How does the egg form?
• Normally, only one mature egg is produced each 28 day cycle. This germ cell is usually perfectly formed.
• An unfertilized egg survives 3 to 4 days.

• How are sperm formed?
• Sperm are formed by the millions. Because of this, not all sperm are perfect.
• There are from 40 to 400 million sperm released each time.
• Healthy sperm can survive 2 to 3 days in the female body.

• The joining of a live sperm and egg.
  • Fertilization normally takes place in the Fallopian tube leading from the ovary to the uterus.
  • Fertilization can be called conception. Pregnancy has now occured.
  • 10 signs you may be pregnant.

• Types of twins:
  1. Fraternal twins are two egg cells fertilized by two sperm cells. These two individuals are no more alike than any other siblings. Fraternal twins occur because the mother has produced two mature eggs during a single cycle.

     There is generally some confusion about twins running in a family. The tendency to produce more than one egg per cycle is an inherited trait. This trait is carried by the female, so twins might be predicted if the females on the mother's side of the family have had fraternal twins. The father and his family do not enter into the equation. Identical and conjoined twins have little if any genetic predictability.

  2. Identical twins are one egg cell fertilized by one sperm cell. The resulting zygote splits in the early stages and develops into two genetically identical individuals.
  3. Conjoined twins usually form in the same way as identical twins, except the zygote does not completely split. Conjoined twins share some body parts.

Interesting twin facts:

A swollen sac was found pressing against the kidney of a 16 year old boy in Egypt in 1997. It turned out to be the remains of his 7 inch long, 4 lb, 6 oz identical twin.

Implantation: The blastocyst attaches to the uterine lining.

Timing is important for implantation.
• What happens if implantation does not occur?
• Describe the placenta.

• What is it?
• Why is it so important?

• It is not "9 months".
• Is it the same for everyone?
• Three ways to calculate due date:
  1. Add 280 days to the date of the last period.
  2. Count back 3 calendar months from the first day of the last period - then add one year and one week.
  3. Add 266 days to the date of fertilization.
• The weight of a normal new-born child is 6 Billion times that of the original fertilized egg.

• Alcohol During Pregnancy

• Amniocentesis - a special procedure that can be performed at 15-16 weeks to obtain a sample of amniotic fluid that is sent to a genetics lab for chromosome analysis.

• Labor - the interval from the beginning of contractions to complete dilatation of the cervix (just over 10 centimeters).

• Birth - a live baby expelled from the mother's body.

Puberty: The body begins to produce sex hormones, causing physical and psychological changes. Sex hormones produced at puberty cause a young person to think about his or her sexuallity. Sexual selection

Licensed Practical Nurse

Day 3 Assignment - Reproduction (Concept Understanding) Use this webpage to answer the following questions: Sperm may move into the fallopian tube in as little as ___(a period of time). What is human chorionic gonadotropin? Describe the role the blastocyst plays in the formation of the placenta. How old is the embryo when the heart begins to pump? When is the embryo most vulnerable to the effects of drugs or viruses? How does the heart rate of a woman change during pregnancy?

Day 4

Short of sterilization, is any form of contraception 100% effective?

Before beginning this page, test your Contraceptive IQ!

Contraception:

Contraception can be defined as preventing live sperm and egg from coming together. This can be done in two basic ways: Barrier method - prevents pregnancy by stopping sperm from reaching the womb. Hormone method - prevents pregnancy by altering the formation of egg or sperm.

• The biological purpose of intercourse is to produce offspring.
• When absolutely sure that your family is complete, sterilization is a certain way to insure fertilization will not occur.
• Without sterilization, not having intercourse is the only method that is 100% effective in preventing fertilization.
• The effectiveness of temporary contraception methods varies with how they are used.

  Choices for temporary contraception: Oral contraceptives (the pill) - 97% to 99+% Implant - 99+% Depo-Provera - 99+% IUD - 97% to 99% Diaphragm - 82% to 94% Vaginal pouch (female condom) - 79% to 95% Condom - 88% to 98% Spermicides - 72% to 97% Rhythm or Calendar Method - 80% to 99% Withdrawal - 81% to 96%

  What about RU 486? Mifeprex® does not fit the definition of a contraceptive because it does not stop sperm and egg from coming together. A positive website A negative website

• What is meant by "Emergency" Contraception?

• Permanent Contraception: Surgical methods usually used by men and women who know they do not wish to have any more children.

Day 4 Assignment - Reproduction (Concept Understanding) Go to this website. After the introduction there is a problem set of 10 questions about birth control. Find the correct answers to these questions. Study this page of frequently asked questions on contraception. Find at least two things that you learned from this website.

Day 5 - 6

Can HIV be transmitted through kissing?

Sexually Transmitted Disease (STD):

• Acquired Immunodeficiency Syndrome
  caused by the Human Immunodeficiency Virus
  • Forms of transmission:
    • Sexual contact with an infected person.
    • Sharing needles and/or syringes with someone who is infected.
    • Infected blood getting into an open cut or splashing into a mucous membrane.
    • Babies born to HIV-infected women may become infected before or during birth or through breast-feeding after birth.
  • What the virus does to the body:
    • The virus effects the immune system by harming the "T-helper cells". As the number of these cells in your body goes down, you become more and more likely to "catch" a disease that your body would normally be able to defend against.
  • Most common opportunistic infections associated with the AIDS syndrome:
    • PCP (Pneumocystis carinii pneumonia), a lung infection.
    • KS (Kaposi's sarcoma), a skin cancer.
    • CMV (Cytomegalovirus), an infection that usually affects the eyes.
    • Candida, a fungal infection in throat or vagina.

Genital warts Human papillomavirus (HPV) Herpes genitalis Herpes simplex virus Chlamydia Bacteria (Chlamydia trachomatis) Gonorrhea Bacteria (Neisseria gonorrhoeae) Syphilis Bacteria (Treponema pallidum) Scabies Mite (Sarcoptes scabiei) Vaginitis Bacteria, Protozoan, Yeast, or Non-biological Hepatitis Hepatitis B Virus (HBV) Hepatitis B Hepatitis C Infectious mononucleosis ("Mono") Epstein-Barr virus (EBV), herpesvirus group

By definition, sexually transmitted diseases are spread by contact with infected human body fluids. There are two reasons why extreme caution should be taken concerning contact with body fluids. First, the physical appearance of an STD carrier may be completely normal. Second, several STD's have no known cure. Once contracted, the disease organism will remain in the body for the rest of your life. The viruses and bacteria that cause STD's are normally easily eliminated outside the body with common disinfectants. There is very little chance of transmission unless body fluids are mixed directly. However, extreme care should always be taken for you own personal protection.

Day 5-6 Assignment/Essay - Reproduction
This assignment must be turned in by the end of class tomorrow to receive credit.

1. Use this essay planning guide to write an essay about viral STD's.

 
More Research Links:

• TeensHealth - The Nemours Foundation
• Medical Dictionary - MedicineNet
• Anatomy of the Human Body - Gray's Anatomy
• Reproductive Rights - The Ten Minute Activist
• Life's Greatest Miracle - PBS
• Pregnancy - iVillage
• Vertebrate Reproduction - George Washington University
• Vertebrate Embryology - George Washington University
• Developmental Biology - University of New South Wales
• Developmental Biology - University of Calgary
• Zygote - Swarthmore College, Swarthmore, PA
• Human Reproductive Physiology - United Medical and Dental Schools, London, U.K.
• Fertility - Atlanta Reproductive Health Care Centre
• Fertility - Fertilitext
• The Pill Turns 40 - Schering Chemical
• Male Contraceptive Compound - RTI International
• Male Contraceptive Pill - The Kaiser Foundation
• It's Your Life - The Kaiser Foundation
• Contraception - Indiana University
• The Basics of Twins - about.com
• Twin Pregnancy - Atlanta maternal-Fetal Medicine
• Women's Health - OBGYN.net
• Development of the Human Embryo - University of Pennsylvania Health System
• Embryo Images - UNC-Chapel Hill School of Medicine
• Morphing Embryos - PBS
• Multi-Dimensional Human Embryo - University of Michigan
• The First 9 Months - ParentsPlace.Com
• Reproductive Health Research - The Alan Guttmacher Institute
• Social Health Information - The American Social Health Association
• Smoking and Reproductive Health - Association of Reproductive Health Professionals
• Methods of Birth Control - Association of Reproductive Health Professionals
• Pregnancy Questions - NOAH: New York Online Access to Health
• Obstetric Ultrasound - By Dr. Joseph Woo
• Baby Information - Baby Net
• Human Milk and Lactation - University of Illinois
• Birth Defects - NOAH: New York Online Access to Health
• Cryogenic Laboratories Inc. - A professional sperm bank
• Anatomy Links - DV Biology
• Health Links - DV Biology

Identical twins must always be the same sex.
Identical twins are formed from one fertilized egg, making them genetically identical.

The adrenal glands in both males and females produce small amounts of the hormone testosterone.

The length of a normal human pregnancy is 38 weeks.
This is two weeks longer than "nine months".

No form of contraception used to prevent pregnancy when having sex is 100% effective.

While small amounts of the virus have been found in saliva, it is generally believed that HIV cannot be transmitted through kissing.