Science & Mathematics - 10 January 2007

1. How does crossing-over lead to greater variability of phenotypes. Any examples of this??

2. What differences would you exepct to see in a population made up of individuals whose chromosomes experince crossing-over frequently compared with a population made up of individuals whose chromosomes do not cross over? Why?

2007-01-10 03:27:07 · 1 answers · asked by chillbamf01 1 in Biology

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find the element,?

Identify the following element, and justify your answer (use webelements.com for help):

It is capable of forming +3 cations, but is unable to form anions.
It has a first ionization energy of 834 kJ/mol.
It has an electron affinity of 103 kJ/mol.
It has an atomic radius larger than 130 pm.
Its oxide is capable of forming either acids or bases.

2007-01-10 03:25:03 · 2 answers · asked by collegegirl 2 in Chemistry

0 ⤊

Do leather conduct electricity?

2007-01-10 03:23:11 · 5 answers · asked by munirlutfi 1 in Physics

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Anyone have a good online Organic Chemistry help website?

I really struggled with organic chemistry last semester but i have to have it to get into grad school. i got a big ol' F in it when all i did was TRY MY HARDEST. i got an A in regular chemistry so i'm not stupid. does anyone have or know of a good online tutoring website? i've found some already but they didn't help. I also had a actual tutor but he didnt help either. are there any secrets to doing well in this class i should know about?

2007-01-10 03:22:35 · 1 answers · asked by kestrelk8 6 in Chemistry

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Is there any easy method to find cube and cuberoot??

2007-01-10 03:22:24 · 7 answers · asked by Anonymous in Mathematics

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was do energy processing organelles help cells do?

i cant figure out what they do to help cells. do they help pass energy or what?

2007-01-10 03:21:17 · 2 answers · asked by babbsie_101 2 in Biology

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In some problems of simple harmonic motion, we take phase constant as zero, and in some, we do not....why?

like we take it as (pie)/2 at extreme position, and sometimes, we write equations ignoring it totally.....how do i know when i gotta take it as zero....if its not specified in the problem?
i promise to select ur answer as the best if i am convinced.
thanks a lot for ur help....

2007-01-10 03:15:00 · 4 answers · asked by practico 1 in Physics

4 ⤊

what is the basic unit of life.?

2007-01-10 03:10:47 · 8 answers · asked by cryvet.6969 1 in Engineering

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What are Lissajous figures ? i know they are something related to simple harmonic motion, but wat are they ?

plz explain clearly.....
thanks a lot for ur help........
i promise to select urs as the best answer, if im convinced.

2007-01-10 03:09:10 · 3 answers · asked by practico 1 in Physics

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How many Combinations of human DNA are there?

How many Combinations of human DNA are there? I.e. how many templates of humans can be created? What is the chance that a another human can exist with identical DNA?
If the entire population of humans that have ever existed are taken to account, can there have possibly been an identical "me" ever in history?
(Obviously we disregard identical twins in this query)

2007-01-10 03:07:11 · 8 answers · asked by AD 1 in Biology

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If the Earth holds people and Space holds Earth, what holds space?

It is like a snow globe! The snow man is in the globe, we hold the globe, Earth holds us, Space holds Earth, what holds space. Do you think that there is something else out there. Something has to hold space.

2007-01-10 03:06:48 · 19 answers · asked by wondering 1 in Astronomy & Space

4 ⤊

sun is supposedly very very hot, can one explain theory 'the higher you go the cooler it becomes'?

2007-01-10 03:05:56 · 11 answers · asked by ndlovu55 1 in Weather

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What is the relation between 1 joule,1 volt, and 1coulomb?

2007-01-10 03:05:47 · 3 answers · asked by Anonymous in Physics

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Chemistry calculations?

Ascorbic acid, (vitamin C, C6H8O6) is a water soluble vitamin. A solution containing 80.5 g of ascorbic acid dissolved in 210 g of water has a density of 1.22 g/mL at 55 degrees C. Calculate the following:

the mass percentage

the mole fraction

the molarity

the molarity of ascorbic acid in this solution

2007-01-10 03:05:30 · 3 answers · asked by bosox1989 1 in Chemistry

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Concentration of solutions?

A solution is made containing 25.5 g phenol (C6H5OH) in 495 g ethanol (CH3CH2OH). Calulate the following:

the mole fraction of phenol

the mass percent of phenol

the molarity of phenol

2007-01-10 03:02:30 · 1 answers · asked by bosox1989 1 in Chemistry

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Punnett Squares HELP!!?

i need some help i am usually really good at biology but one thing i do not understan are these punnett squares.THANKS! :)

Refer to the following information to answer Questions 4 through 7.A horticulturalist wants to produce geraniums with specific characteristics. She knows that the trait of red flowers is governed by the allele R (RR and Rr) and the trait of white flowers is governed by the allele r (rr).

1. The horticulturalist plans to cross a geranium that is true-breeding for red flowers with a geranium that is true-breeding for white flowers. What would this Punnett square look like.

2. The horticulturalist crosses two geraniums from the F1 generation. Look at the Punnett square to see this cross. What ratio of red- to white-flowering plants would you expect to see in the phenotypes of the F2 generation?
A. 1 red: 3 white
B. 3 red: 1 white
C. 2 red: 2 white
D. all red
the punnett square looks like this
R r

R RR Rr

r Rr rr

2007-01-10 02:58:51 · 2 answers · asked by Anonymous in Biology