Asexual Reproduction

Here's some good stuff:

Paramecium with binary fission:



Puff balls:


Spores and Insects (Not for the faint of heart! Fast forward to 1:09 to see it growing....)


Budding in Yeast

Honors Bio - Break Assignment Solutions

Solutions to use in studying for the exam tomorrow:

1. (4)
2. (1)
3. (4)
4. (1)
5. (1)
6. (2)
7. (3)
8. (1)
9. (2)
10.(4)
11.(3)
12.(4)
13.(1)
14.(1)
15.(1)
16.(1)
17.(1)
18.(2)
19.(2)
20.(1)
21.(3)
22.(4)
23.(1)
24.(4)
25.(2)
26.(a)
27.(a)
28.(d)
29.(a)
30.(4)
31.(3)
32.(d)
33. doesn't exist!
34. doesn't exist!
35.(b)
36.(d)
37.(a)
38.(a)
39.(d)
40.(a)

Polymerase Chain Reaction and Gel Electrophoresis - What a mouthful!

Today's lesson focuses on the process of gel electrophoresis, which is a process typically used to compare different DNA samples to each other. The basic idea is as follows:

1. A sample of DNA (from a postage stamp, blood sample, skin cell, etc) is combined with restriction enzymes, which cut the full DNA sample into pieces at specific base pair sequences.

2. The sample of pieces is used in a polymerase chain reaction, or PCR. This takes the small pieces of DNA in the sample and creates MANY copies of each piece so that there is enough DNA that the sample can be analyzed.

3. This larger sample of cut DNA pieces is combined with a dye and placed in a gel electrophoresis set-up. By applying a voltage across the gel, the differently sized pieces of DNA are pulled towards the positive side. The smaller pieces move more quickly than the larger pieces. As a result, the different sizes of pieces spread out like runners in a race.

4. The pattern of colored bands is unique and is related to the number of pieces of each size in the original sample of DNA. The number of pieces of each size (and therefore a particular gel pattern) is unique to an individual. By comparing a gel made of an unknown person to gel patterns made of known identities, it is possible to determine the unknown identity.

Here are some videos to help you get it:
The Power of DNA:


Applications of DNA Fingerprinting:



PCR reaction:


DNA fingerprinting again:

Genetic Engineering!

The videos from class:

This video talks about how a bacterial plasmid is cut by restriction enzymes, allowing a gene to be inserted into the bacterial DNA. The bacterium then produces the proteins encoded in the DNA of the inserted gene.



An animation showing the DNA being cut by the restriction enzyme EcoR1 - look out for the enzyme searching the DNA for a specific sequence.


In this video, the nucleus of an egg is removed, and is replaced by the nucleus of a body cell (such as a skin or muscle cell). Using the nucleus, the egg then divides and develops into an embryo using the instructions encoded in the DNA. The cells in this egg are exact clones of the skin cell used to create it:

Happy Snow Day

As great as biology can be, today we have physics to thank for a day off.



Check out this site for information on snowflakes.

As a result of the extra day off, we will plan to push the honors exam to after break. Enjoy the day!

HW solutions - Honors and Regular

Hey all,

Here are your solutions. Enjoy!

Regular Class:
p. 315, 3-5, 7-9, 23

3. B
4. C
5. A
7. B
8. C
9. B

23. There are many different types of mutations - gene mutations involve a change in one or more nucleotides in a single gene. Chromosomal mutations are changes in the structure or number of whole chromosomes. Insertion mutations add one or more bases to a sequence. Deletions remove one or more bases from a sequence. Substitution mutations switch one base into another. Inversion mutations reverse the order of a sequence of two or more bases.

p. 269: #2, 4, 5
2. Punnett squares are used to predict and compare the possible outcomes (genotypes) that could result from a cross.

4. Genotype is the specific pair of alleles for a gene that an organism has (Bb or bb); phenotype is the physical trait or characteristic that the organism displays. (Brown hair or blond hair)

5. The cross will be tt x Tt, which results in genotypes Tt, Tt, tt, tt. This means 50% of the plants will be tall.

Honors:

p. 274 - 1, 3

1. During gamete formation, pairs of alleles for different traits segregate (separate) independently from each other. For example, the alleles for seed type (R or r) and seed color (Y or y) in pea plants are independent from each other. This means that in both genotypes RrYY and Rryy, the seed type will be round, while the seed color changes from yellow to green.

3. In incomplete dominance, two alleles combine to produce a single phenotype that is "in between" the dominant and recessive. The example used in class is the snapdragon flower, which is pink for the heterozygous case of Rr. In codominance, each allele is expressed separately in the same organism. For example, cats expressing codominant traits of brown (B) and orange (O) fur might result in fur that is BOTH orange and fur in the genotype BO.

Human Genome Animation

This animation is from the Human Genome Management Information System of the U.S. Department of Energy Office of Science. It shows the details of what the Human Genome project has discovered about the locations of genes on human chromosomes.

http://www.ornl.gov/sci/techresources/Human_Genome/posters/chromosome/karotypehome11.swf

I don't mean to be codominant, but...

Here are the solutions to today's worksheet:

1.
a) If R was the dominant allele, then the genotype Rr would be red, not pink. In this example, Rr represents a third genotype in which the dominant allele is only partly dominant, which makes it pink, a mixture of red and white.

b)
i.100 % pink flowers
ii. 50% white, 50% pink

c) rr x rr or Rr x rr

2.
a)The alleles are A, B, or o - these alleles are used to construct ALL of the other genotypes for blood type.
b)
i. 50% type AB, 50% blood type B (genotype Bo)
ii.50% type A (Ao), 50% type B (Bo)
c) The parents must have been Ao x Bo

3.
b) 4 BbTT, 4 BbTt (these are all Brown fur, Long tail), 4 bbTT, 4 bbTt (these are all black fur, Long tail),
c) 50% have this trait.

Secret word...karyotype. Look it up and be ahead of the game.

Also, click here to read some facts about the human genome.

It's Hip to be a Punnett Square - Honors Classwork Solutions

Hi Everyone,

Great work today in the new classes - I think they will work out well!

Here are the solutions to the handout from class:

Front Page (Level I questions...)

1. Genotypes: 2Gg, 2gg, Phenotypes are 50% green, 50% yellow
2. Genotypes: 2TT, 2Tt, Phenotypes are 100% tall
3. Genotypes: 2Tt, 2tt, Phenotypes are 50% tall, 50% short.
4. Genotypes: 2 Rr, 2rr, Phenotypes are 50% red, 50% white
5. Genotypes are all rr, Phenotypes are 100% white
6. Genotypes are all BB, Phenotypes are 100% black chicken.

Back page problems (Level II)
1. B is brown, b is tan. The cross is BB x Bb.
Genotypes: BB, Bb, BB, Bb, Phenotype is 100% brown mouse.

2. W is white, w is brown. The cross is Bb x Bb.
Genotypes: BB, Bb, Bb, bb, Phenotype is 75% white, and 25% brown.

3. R is red, r is white. The cross is Rr x Rr.
Genotypes: RR, Rr, Rr, rr, Phenotype is 75% red, 25% white.

4. T is tall, t is short. The cross is TT x Tt.
Genotypes: TT, Tt, TT, Tt, Phenotype is 100% tall plant.

5. Period 3 - note the following fact pointed out by someone in the 4th period class: Since it says the white rabbit is heterozygous, this means that WHITE is dominant (not black). If W is white and w is black, then the cross is Ww x ww.

Genotypes: Ww, Ww, ww, ww, Phenotype is 50% white, 50% black.

The secret phrase for today - independent assortment. Extra bonus to those that figure out how this relates to today's lesson....