Wednesday, January 26, 2011

Justin A.

We started off the day by turning UP pg 11 and 12. Next we filled out a sheet about the science class we are going to take next year. Then we began notes.

  • All life is connected
  • Evolution is cause of today's diversity.
  • Charles Darwin came up with the idea. He wrote "The origins of Species" in 1859.
  • 2 main points in book:1. "decent with modification"(this means every descendent is a little different. 2. the mechanism for evolution is "natural selection"
  • Darwin loved nature and traveled world in HMS Beagle." He observed species on different islands
  • saw variety of finches in the Galapagos Islands.
  • After many generations, 2 populations could become dissimilar enough to be separate. (called divergent evolution)
  • Darwin observed the finches' beaks and color.
  • Natural selection- 3 main points:
  1. Overproduction- leads to struggle for existence among individuals of a population.
  2. Individuals in a population vary in traits, no 2 are alike.
  3. Individuals with best traits to survive leave greatest number of surviving offsprings.
  • Nature decides what traits are most fit.
  • Adaption is accumulation of favorable variation in a population over time.
  • Darwin looked at Artificial Selection- Humans modify species to get best traits.
  • In Artificial selection. humans change trait, not nature.
  • natural selection today, i.e.= Pesticide- now some insects are immune to pesticide.
  • Camouflage is an example of evolutionary adaption. (mantids)

  • Evolution- 2 modern definitions:
  1. genetic composition changes over time
  2. all life descended from common ancestor
  • Scientist during Darwin's time thought earth was young, and that Darwin's idea was radical
  • Anizimander- Greek philosopher who though simpler forms of life preceded more complex life.
  • Aristotle- Greek philosopher thought species were fixed and didnt evolve.
  • Buffon- studied fossils. Said Earth is mush older. Said species in fossils were ancient versions of modern species.
  • Lamarck- said the life evolves through adaptation.
  • He said "Inheritance of Aquired Characteristics" (not using a body part would cause offspring to be born without that body part.
  • Lyell-said ancient earth was sculpted by geologic process. (earthquake and mountains)
  • Graualism principle.
  • Wallace-developed concept of natural selection. Had same idea as Darwin but Darwin published his ideas before Wallace did.
  • fossils- preserved remnants of impressions left by organisms that lived in the past.
  • Younger strata are on top of the older ones. Level reveals "relative age"
  • Fish like vertebrats are oldest, then amphibians, then reptiles, then mammals and birds.
  • Paleontologist- scientise who studies fossils.

Homework: UP pg 5, E.C. pg 6 and/or M&M.

Next scribe: Katie

Monday, January 24, 2011


  • Everything has evolved or is evolving(this has been shown in all previous chapters)
  • Usually takes millions of years, this is why fossils are best evidence that evolution took place.
  • Evolution is often politicized, for example our food pyramid in schools say we should eat a lot of red meat but when a dieticist was asked, red meat was placed in the same section of chocolate, to not be eaten often.
  • Some people believe that evolution is make believe or doesn't exist. This is obviously untrue because if there was no evolution, species would not be able to adapt to their habitats conditions and could become extinct.
Charles Darwin:
  • was an English naturalist with a fascination of nature that came from a well known family.
  • He came up with the theory of evolution and natural selection; The change of a species where it is "survival of the fittest". He also believed that all living things traced back to one common ancestor.
  • He was a revolutionary because he went against the science, politics, and the church by creating new ideas that especially went against the church's opinion that God set up all species on earth.
Process of natural selection:
  1. Genetic variation
  2. Overproduction of offspring
  3. Struggle for existence
  4. Differential survival and reproduction
Next Scribe...Justin A

Tuesday, January 11, 2011

Reproductive Alternatives and Contraception

Contraception means a deliberate prevention of pregnancy that may work if used correctly.

Some types of contraception are:
Tubal Ligation- path of sperm blocked to egg
Vasectomy- vas deferens is cut
Rhythm Method- temporary abstinance
Withdrawal- removal of penis before ejaculation from vagina
Barrier Methods- physically preventing sperm from reaching the egg
Spermicides- sperm killing chemicals
Birth Control Pills- prevent ovulation
Morning After Pills- just like abortion
Abstinence- no sex at all

Most of the pills are just messing with the hormones in a female's body.

The difference between STD's and STI's:
STD's=sexually transmitted Diseases
STI's=sexually transmitted Infections

Viral STI's are not curable, but bacterial STI's are curable with drugs.

Reproductive Alternatives

When a couple has been having unprotected sex for over a year and are unable to conceive a child, it is official that one of them or both are infertile.

Male problems:
-low sperm count
-erectile dysfunction (impotence)

Female problems:
-lack of eggs
-failure to ovulate
-cannot support a growing embryo

Treatments for male problems:
-briefs to boxers-->to regulate the body temperature down there
-drug therapy
-sperm injection/bank

Treatments for female problems:
-hormone injections
-donor egg
-surrogate mother
-In Vitro fertilization*

*In Vitro fertilization

When a couple cannot concieve a child, they give their sperm and eggs to a laboratory and they sperm and eggs are combined outside of the female's body. After they eggs have been fertilized, multiple are inserted into the female's body, at about the eight cell stage, so that at least one survives. This can result in more than one baby.

Posted by Sonali

Next Scribe=Carey

Monday, January 10, 2011

1/10/11- Nick S.

Today in class we took notes on Pregnancy:

Gestation- carrying of developing young within the female reproductive tract

· Humans = 266 days (about 38 weeks)

· After 1 week after conception, the embryo (blastacyst) implants in the endometrial wall of uterus

· Stem cells begin to grow

· Trophoblast- outer cell layer, becomes part of the placenta

· Placenta- organ the provides nourishment and oxygen to the embryo, also gets rid of waste.

There are 4 pieces of life support once the embryo implants itself into the uterus

1) Amnion- this is a fluid filled sac that encloses and protect the embryo

2) Yolk sac- contains no yolk, produces embryos first blood and germ cell

3) Allantois- forms part of the urinary bladder and part of the umbilical cord

4) Chorion- part of the placenta, maintains the high level of Estrogen and Progesterone

· Contains chorionic villi- embryonic blood vessels that are in close contact with maternal blood supply

· Mom`s blood and embryo`s blood DO NOT MIX!

· By Diffusion, oxygen, nutrients, antibodies, virus (german measles) and drugs move from mom to embryo and waste moves from embryo to mom

First Trimester

· 5 weeks old embryo
· ~ 1 month- 7 mm
· Brain and spinal cord
· 4 limbs buds, short tail and gill pouches

· 9 weeks Fetus~ 5.5 cm
· All organs and boys parts
· Can move

Second Trimester

· Ultra sound is around 18 week’s fetus, can show sex or abnormalities
· 16 week fetus~ 6 cm
· 20 week fetus~ 19 week and is 1/2 kg (1 lb)

Third Trimester

· Circulatory and respiratory systems prepare for breathing air
· Rotates head towards cervix
· At birth ave=
o 50 cm (20 in)
o 2.7-4.5 kg (6-10 lb)


· Labor- strong rhythmic contractions of the uterus controlled by hormones
o Estrogen- induces oxytocin receptors
o Oxytocin- causes uterus to contract

· Cervix dilates (0 to ~ 10 cm), ave. 6-12 hours
· Full dilation of cervix to birth, strong contractions, ave. 20-60 minutes, clamp umbilical cord
· Delivery of the placenta (afterbirth)~ 15 minutes after birth

Home work:

Finish stem cell reading and Questions- due Wednesday January 12th

Study for unit 6 test on Thursday January 13th

Study for Finals on Tuesday January 19th

Next scribe is: Carey E.

Friday, January 7, 2011

1/6/11-Yunsu Y.

Today in class we went over our labs that we did for homework yesterday and they were collected. Then we continued our notes on hormones.

Hormone Notes Continued...

-Negative Feedback Mechanism (Estrogen):

  • this happens when levels of estrogen are low causing menstruation to occur. (FSH/LH released)
  • also, when levels of estrogen are too high, pituitary stops release of FSH/LH.

---when the egg is not fertilized the levels of these hormones fall.

BUT, when the egg is fertilized/pregnant: the levels of these hormones will stay consistent.

-IF the women is pregnant, the baby makes its own hormones, HCG (Human Chorionic Gonadotropin).

  • if this hormone is present, a urine test will usually tell you that you are pregnant.
  • the baby's hormone will get mixed into the mother's kidneys and will have HCG present in her urine.

-Results From Hormones:

  • Males: deeper voice. more facial hair and on body, chest broadens, larger muscles, and longer growth stage.
  • Females: Enlargement of breasts and reproductive organs, wider hips (for the baby), hair in armpits and pubic area, menstruation, and fat deposits under skin.

-----Then after notes we went over UP 15-18

-----then worked on Lab 9-14

HW: Finish Lab UP9-14, Stem Cell Reading and The Last Word worksheet, and STUDY for FINALS and also Unite TEST on THURSDAY 1/13/11!!

Next Scribe: Nick S.

Differences in male and female gametogenesis:

Females: Males:
ovaries testes
1 gamete parent cell 4 gamete parent cells
large,nonmotile, full of nutrients Small, motile few nutrients
oogenesis completed with sperm oogenesis completed before sperm is out of testes

Hormones & the Menstrual System:

4 hormones control menstrual system
  • Menstruation happens when Estrogen and progesterone are low
  • Progesterone causes lining of the uterus to thicken
  • When LH peaks it causes ovulation
  • Hypathalamus tells Auterior Pituitar to release LH
  • If 1 hormone does not work the system will not work
  • synchronize ovarian and menstrual cycles

Goal of female cycle: to get ready for fertilization(just in case)

4 Phases of Menstrual Cycle:

  1. Menstruation-about day 1-5, lining leaves the body
  2. Follicle-follicle matures
  3. Ovulation-day 14, mature egg released from ovary
  4. Luteal-development of the corpus luteum

Wednesday, January 5, 2011

1/5/10- Justin A.

Today we started off the day by going over UP page 4. For the rest of class we went through notes.

Human Reproduction
  • Both male and female have gonads. (organs that produce gametes). Males have testis and Females have ovaries.
Female Reproductive Anatomy
  • Ovaries- site of gamete production.
  • Follicles-Consists of single developing egg with tissue to nourish it.
  • Ovulation- When the egg is ejected from the follicle.
  • Corpus Luteum- The remaining follicle tissue after ovulation.
  • oviduct (fallopian tube)- Where fertilization takes place.
  • Uterus- site of pregnancy. Has muscle to expand to accommodate the fetus.
  • Endometrium- Layer of tissue that lines the uterus. Site where embryo implants itself.
  • embryo- from zygote to 9 weeks.
  • fetus- 9 weeks to birth.
  • cervix- neck at bottom of uterus
  • vagina-(birth canal) where sperm is deposited.
  • urethra- Tube for urine.
  • Labia Minora- skin around opening to vagina.
  • Labia majora- skin around genetil region.
  • Hymen- thin membrane partially covering vagina.
Male Reproductive Anatomy

  • Penis- Contains erectile tissue. Shaft that supports glans.
  • Testes- male gonads located outer body in scrotum.
  • scrtotum- sac that holds testes away from body.
  • epididymis- stores sperm
  • ejaculation- expulsion of sperm containg fluids from penis.
  • Pathway of sperm during Ejaculation.
  1. Leave epididymis.
  2. Vas deferen -duct
  3. seminal vesical and prostate gland.
  4. Empties into urethra
  5. semen- 95% fluid from glands and 5% sperm cells.

Gametogenesis- (production of gametes)
  • gametes are haploid ccells developed in meiosis.
Female Gametogenesis
  • oogenesis- developement of eggs with the ovaries.
  • At birth each follicle contians 1 dormant primary oocyte. (diploid cell)
  • FSH (Follicle Stimulating Hormone) trigger further developement of follicles.
  • Follicle enlarges and oocyte completes meiosis
  • Secondary oocyte recieves almost all of cytoplasm. Other degenerates.
  • IF sperm fuses with secondary oocyte, it will complete meiosis 2.
Male Gametogenesis
  • spermatogenesis- formation of sperm cells.
  • Some cells go under mitosis while the others go through meiosis.
  • four spermatids are produced after meiosis 2.
  • Spermatids are immature to sperm.
Homework:Pre lab 35-38,

Next scribe : Carey E.

Monday, January 3, 2011


1/3/11- Today, we began a new unit: reproduction. The main concept that we learned was the main differences between external and internal fertilization and external and internal development. We also completed the first 3 pages of notes, which can be found on Mrs. Andrew's moodle page.
So, the main differences between external and internal fertilization is the fact that external fertilization involves the union of gametes outside the body and usually involves water-type environments. Internal fertilization, however, involves the union of gametes inside the body and is most common in terrestrial animals.
In addition, the main differences between internal and external development is the fact that external development involves growth of offspring outside the body, and internal development involves growth of offspring inside the parent's body.
Besides the types of fertilization and development, we also discussed the two types of reproducing organisms: sexual and asexual. Sexually reproducing animals reproduce via the fertilization of sperm (from a male parent) and egg (from a female parent). An asexually reproducing organism is one who literally "clones" itself, because of the fact that they would reproduce without the fertilization process.

Justin A. is the next scribe poster.