Question in English:
A female carries a recessive lethal gene (l) on one of her X chromosomes, and a normal dominant allele (L) on the other. What is the sex ratio to be expected in this woman's dependency if she marries a normal man?
Answer:
2/3 females
1/3 males
Explanation:
Females have two X chromosomes (XX) and males have an X and a Y chromosome (XY).
The genotype of the female is XLXl. The genotype of the male is XLY, since he is normal.
The possible genotypes are:
<u> XL Xl</u>
<u>XL</u> <em>XLXL XLXl</em>
<u>Y</u> <em>XLY </em><em>XlY</em>
<em />
All female offspring will be normal as they will always have one normal copy of the X chromosome from their father.
50% of the male offspring will be normal, but 50% will inherit the lethal gene from their mother.
Because the allele is lethal, that means XlY males will not be born.
That means 2/3 of the children will be females, and 1/3 will be males.
FAULT-TOLERANT computer systems are systems that are built with
the ability to keep working to
a level of satisfaction, even in the presence of faults within one or more of
its components. <span>This
fault tolerant ability is sometimes referred to as graceful degradation</span>
Answer:
The number of STR repeats is unique and therefore it is considered as an allele of that <em>locus</em>
Explanation:
Short Tandem Repeats (STRs), also known as microsatellites or simple sequence repeats (SSRs), are short DNA sequences with a size of 1-6 nucleotide bases which may be many times repeated in tandem. STRs localize in specific regions of the genome (<em>loci</em>) and therefore they are molecular markers. Gel electrophoresis a technique used to separate DNA fragments based on their size. In consequence, the pattern of STR repeats or 'alleles' obtained by electrophoresis can be used to identify individuals. In a gel electrophoresis, STR markers produce different bands that run more slowly or faster on the gel in different lanes according to their size (e.g., more slowly >> higher size of the STR sequence), and thereby STR alleles are unique and serve to identify individuals.
We know that oil floats on water and do not mix
<span>
What happens to the oil when you first pour it in? It flows into the water, but then seperates.
Why does this happen? oil is lighter than water and the molecules of the oil are attracted to the other oil molecules, not water, the water molecules the same
What kinds of animals would be most affected by an oil spill at the beginning? animals that live their lives near the surface of the ocean. Why? because now the water that was clear and free-flowing is now dark and sticky. oil also changes the way how some animals survive so make their ways less effective. one example are birds like pelicans
Use a spoon to stir the oil for 30 seconds.
Answer the following questions:
What natural action stirs the real ocean? ocean currents caused by wind and the earth's roation
What happened to the oil? went back to the top
Even if you can’t see it, is all the oil still in your ocean? yes
Which animals in the ocean become affected after wave and current
action causes some of the oil to settle to the bottom, or be absorbed
into the water? bottom-feeders
Add a splash of dish detergent to the mixture and stir.
Answer the following questions:
What happened to the oil? it mixed with the water Is it all still in the ocean? yes
Sometimes cleanup efforts involve dumping a soap mixture over a spill area. Why is this done? to bond the oil to the detergent and the detergent to the water. so they can grab all the oil
What might be a negative effect of dumping the soap?</span> soap has chemicals that could upset the ballance of the ecosystem and kil some animals/plants
