An onion is made-up of layers, which is separated by a thin skin or
membrane. The cells are easily visible under a high power, compound microscope
and the preparation of a thin section is straightforward.<span> </span>
<span>The correct
procedure for preparing a stained wet mount of onion epidermis are as follows.
First, place a piece of thin onion epidermis on a slide. Second, add one drop
of water and put one edge of a coverslip in the water drop, and then slowly
lower the opposite edge to the water. Third, put one drop of stain at one edge
of the coverslip and put a piece of paper towel at the opposite side of the
coverslip. Lastly, allow the towel to absorb some water so that the stain will
move under the coverslip and view it under a microscope. </span>
Answer:
A major factor in determining the mode of nitrogen excretion is the availability of water in the environment. Generally, aquatic animals excrete mostly ammonia, whereas terrestrial animals excrete either urea or uric acid.
Explanation:
Answer:
Tt - 2/4 = 1/2 or 50% Heterozygous TALL
tt - 2/4 = 1/2 or 50% Homozygous Dwarf
Explanation:
So let's make a Punnett for this so you can see what the outcome is yourself:
Tall is <u>dominant</u> - T
Dwarf is <u>recessive</u> - t
Heterozygous means that they have one of each allele. The genotype of one parent would be then Tt.
***It is heterozygous tall because Tall is a dominant trait so if it is accompanied by the recessive trait dwarf, then the Tall allele would mask it.
The other parent is a dwarf plant. The genotype would then be tt.
*** Now for a recessive trait to appear, it should not have a dominant trait mixed with it, which could mask it. The result then is homozygous recessive or homozygous Dwarf.
So now that we know the genotypes of the parent plants, we can put it into a Punnet:
t t
T Tt Tt
t tt tt
As you can see, out of the 4 outcomes we have:
Tt - 2/4 = 1/2 or 50% Heterozygous TALL
tt - 2/4 = 1/2 or 50% Homozygous Dwarf
Smoking during pregnancy affects your and your baby's health before, during, and after your baby is born. The nicotine (the addictive substance in cigarettes), carbon monoxide, lead, arsenic, and numerous other poisons you inhale from a cigarette are carried through your bloodstream and go directly to your baby. Smoking while pregnant will:
<span>Lower the amount of oxygen available to you and your growing babyIncrease your baby's heart rate<span>Increase the chances of miscarriage and stillbirth</span>Increase the risk that your baby is born prematurely and/or born with low birth weightIncrease your baby's risk of developing respiratory problems</span>
The more cigarettes you smoke per day, the greater your baby's chances of developing these and other health problems. There is no "safe" level of smoking for your baby's health.
Answer:
The correct answer is -
1. right-handed
2. right-handed
3. positive
4. left-handed
5. negative
6. negative
Explanation:
In a circular bacterial chromosome, the structure of DNA is a right-handed double helix In a circular bacterial chromosome.
If DNA is twisted in the right-handed direction, it becomes overwound. Overwinding results in positive supercoiling takes place. If DNA is twisted in the left handd direction, it becomes underwound. Underwinding results in negative supercoiling.
f. One effect negative supercoiling in bacterial chromosomes is to promote separation of the two strands of DNA in the double helix
