February 7th

CJ P.
Took notes today. Lots o' notes.
HW: 39-43 in UP. Read ch. 1, 13, 14, 15, 17. Quiz tomorrow
Notes pages 1-11 in 7B packet.

LIFE ON ANCIENT EARTH
Earth theories on life development:
1. BIG BANG - great big explosion and condensed forming atoms.
4 conditions necessary for chemical evolution:
1. No free oxygen. So no mammals.
2. Energy - built up by storms, volcanoes, and UV radiation.
3. Chemicals
4. Time.

OPARIN HYPOTHESIS:
Simulated mini big bang. mini bang.
Found monomers which make polymers and amino acids and building blocks and and and RNA and DNA bases!

HOW DID LIFE FORM?!
1. life from non life.
2. life from life
3. Earth's new compounds.

EARTH SOUP = primordial.

Stages of origin of life:
1. Synthesis from abiotic chemicals.
2. linked monomers to make polymers (amino acids)
3. Origin of SELF replicating
4. Formation of pre-cells using monomers and polymers to form precells (no nuclei)
THESE CAME FIRST: Single cell, anaerobic, asexual, heterotrophic.

cell theory:
Cells are building blocks of life, cells come from other cells, all living things contain cells.

How did species evolve? From natural selection! Nature selected the fittest.

MACROEVOLUTION:
Speciation: creating new species. NONBRANCHING vs. BRANCHING
NONBRANCHING turns into different species
BRANCHING creates a new species and keeps the original ancestor as well.

SPECIES create FERTILE offspring!
REPRODUCTIVE BARRIERS
PREZYGOTIC BARRIERS
1. Temporal isolation ---> TIME
2. Habitat isolation ----> some species live in winter, some in fall
3. Behavioral isolation ---> species must understand mating rituals, if not, no game.
4. Mechanical isolation ----> sex organ must work.
5. Gametic isolation ----> sex organs work together, but gametes do not work.

POSTZYGOTIC BARRIERS
1. Hybrid inuiability---->offspring dies early in life
2. Hybrid sterility ----> offspring lives but is infertile/sterile

allopatric - other country. Some organisms are physically separated making it impossible for them to mate and produce new species
sympatric - together. new species live amongst parent species.

polyploidy - sudden speciation



My name is CJ and thank you for joining us on this week's episode of Honors Biology Period Three: THE BLOG.

Back to you, James (aka next scribe)

STUDY, QUIZ TOMOMO.

Feb 4

Hardy-Weinberg
important things to remember:

Punnett Squares
-know where to place dominant homozygous, heterozygous, recessive homozygous











p= dominant
q= recessive

p+q=1
p^2 + 2pq + q^2 = 1

If you know p, then you know q (and vice versa)

know the difference between frequency and percentage

know the difference between finding the frequency/percentage of a gene (p/q) and population (2pq/p^2/q^2)

read the question carefully- the given info might not be what you think at first
go back to genetics notes if you forgot recessive/ dominant diseases

Notes
Vocab
-microevolution
-genetic drift:
-bottleneck/founder effect
-gene pool
-gene flow
-mutations
-natural selection:
-directional, diversifying, stabilizing
-darwinian fitness

Next scribe - CJ

Feb 1st

Today, we went over answers to UP pgs. 17A-E and notes.

WHAT NOTES???

Modern synthesis: the fusion of genetics with biology

Modern synthesis is a study of variations in populations caused by mutations and sexual recombination.

Population: group of SAME SPIECIES living in same area at same time (Important!)

Gene Pools: all of the alleles in all the individuals making up a population (how many big and small alleles)

Allele: form a trait

Ex: Wildflower with only two varieties-

Red flowers = R & white flowers = r

Suppose 80% or .8 of all flowers in the gene pool have the R allele.

p = relative frequency (how common something is) of the dominant allele (R), so p = .8

q = frequency of the recessive allele (r), so q = .2

YOU MAY BE THINKING, “BUT WHY?”

Since there are only two alleles for flower color, then p+q=1 (MEMORIZE FOR TEST)!

Now that we know the formula, we can find the frequencies of the different genotypes in the population IF the gene pool is completely stable (non-evolving).

Meaning, no one can leave or join the population.

This is called the Hardy-Weinberg equilibrium.

G.H. Hardy questioned, “How can both dominant and recessive alleles remain in populations? Why don’t dominants simply drive out recessives?”

It was discovered that genetic recombination does not by itself change the overall composition of the gene pool. They examined the behavior of alleles in an idealized population in which five conditions hold:

1. No mutations occur

2. No net movement of individuals in or out of the population

3. Population is large enough

4. Mating is random

5. All alleles are equally viable (no natural selection)

• Ex: Dwarfism -> Aa = Dwarf aa = normal AA = too much dwarfism in you, you can’t survive

This ideal environment is hard to find.

Now, back to the wildflower problem!

What’s the probability of producing an RR individual by “drawing” two R alleles from the pool of gametes?

R sperm x R egg (p x p) -> .8 x .8 = .64, or 64% of the plants in the population will have the RR genotype.

Well then, what is the frequency of rr individuals in the population?

r x r (q x q) -> .2 x .2 = .04, or 4% of the plants in the population will have the rr genotype.

What is the frequency of Rr in the population?

Rr + rR, or 2pq

2 (.8 x.2) = .32, or 32% are Rr with red flowers.

General formula: p^2+2pq+q^2=1 (MEMORIZE)!

You can use a Punnett Square to solve the problem as well.



Tonight’s homework:  UP pgs. 31-36 due Thursday

Next Scribe: Christine K.

Justin A.

1/26/11

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.

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

Evolution

• 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

Reproductive Alternatives and Contraception

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 EFFECTIVE METHOD!

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

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

Placenta
· 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)

Childbirth

· 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.