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4 years ago

Which of these are the two major sources of nitrate pollution in rivers?

1 answer:

3 0

Rivers can be polluted by nitrates because the fertilizers in the field that contain nitrates are washed into the river because of rain and flooding. Other source of nitrate pollution in the rivers is the mixing of sewage which contains human and animal wastes.

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The greatest cause of the worldwide loss of species is ________.

Bad White [126]

The greatest cause of the worldwide loss of species is human activity. I think

7 0

4 years ago

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If two genes are found on different chromosomes, or if they are far enough apart on the same chromosome that the chance of a cro

nika2105 [10]

Complete question:

A wild-type tomato plant (Plant 1) is homozygous dominant for three traits: solid leaves (MM), normal height (DD), and smooth skin (PP).

Another tomato plant (Plant 2) is homozygous recessive for the same three traits: mottled leaves (mm), dwarf height(dd), and peach skin (pp).

In a cross between these two plants (MMDDPP x mmddpp), all offspring in the F1 generation are wild type and heterozygous for all three traits(MmDdPp).

Now suppose you perform a testcross on one of the F1plants (MmDdPp x mmddpp). The F2 generation can include plants with these eight possible phenotypes:

solid, normal, smooth

solid, normal, peach

solid, dwarf, smooth

solid, dwarf, peach

mottled, normal, smooth

mottled, normal, peach

mottled, dwarf, smooth

mottled, dwarf, peach

Assuming that the three genes undergo independent assortment, predict the phenotypic ratio of the offspring in the F2 generation.

Answer and Explanation:

Cross 1:

Parental) MMDDPP x mmddpp

F1) MmDdPp

Cross 2: Testcross

Parental) MmDdPp x mmddpp

Gametes) MDP MdP MDp Mdp mDP mdP mDp mdp

mdp mdp mdp mdp mdp mdp mdp mdp

Punnet Square)

mdp

MDP MmDdPp

MdP MmddPp

MDp MmDdpp

Mdp Mmddpp

mDP mmDdPp

mdP mmddPp

mDp mmDdpp

mdp mmddpp

F2) 8/64 = 1/8 MmDdPp, solid leaves, normal height, smooth skin

8/64 = 1/8 MmddPp, solid leaves, dwarf height, smooth skin

8/64 = 1/8 MmDdpp, solid leaves, normal height, peach skin

8/64 = 1/8 Mmddpp, solid leaves, dwarf height, peach skin

8/64 = 1/8 mmDdPp, mottled leaves, normal height, smooth skin

8/64 = 1/8 mmddPp, mottled leaves, dwarf height, smooth skin

8/64 = 1/8 mmDdpp, mottled leaves, normal height, peach skin

8/64 = 1/8 mmddpp, mottled leaves, dwarf height, peach skin

Another way of predicting the phenotypic ratio of the offspring in the F2 generation is by performing a testcross for each gene by separately and then multiplying their genotypic proportions. This is:

Leaves Gene

Parental) Mm x mm

Gamtes) M m m m

Punnet Square) M m

m Mm mm

F2) 1/2 Mm

1/2 mm

High Gene

Parental) Dd x dd

Gamtes) D d d d

Punnet Square) D d

d Dd dd

F2) 1/2 Dd

1/2 dd

Skin Gene

Parental) Pp x pp

Gamtes) P p p p

Punnet Square) P p

p Pp pp

F2) 1/2 Pp

1/2 pp

To get the phenotypic ratio of the offspring we multiply the genotypic proportion for each trait by the genotypic proportions of the other two traits, like this:

For plants with solid leaves, normal height, smooth skin

solid leaves ratio -> 1/2

normal height ratio -> 1/2

smooth skin ratio -> 1/2

MmDdPp ratio: 1/2 x 1/2 x 1/2 = 1/8

For plants with solid leaves, dwarf height, smooth skin

MmddPp ratio: 1/2 x 1/2 x 1/2 x 1/2 = 1/8

For plants with solid leaves, normal height, peach skin

MmDdpp ratio: 1/2 x 1/2 x 1/2 x 1/2 = 1/8

For plants with solid leaves, dwarf height, peach skin

Mmddpp ratio: 1/2 x 1/2 x 1/2 x 1/2 = 1/8

For plants with mottled leaves, normal height, smooth skin

mmDdPp ratio: 1/2 x 1/2 x 1/2 x 1/2 = 1/8

For plants with mottled leaves, dwarf height, smooth skin

mmddPp ratio: 1/2 x 1/2 x 1/2 x 1/2 = 1/8

For plants with mottled leaves, normal height, peach skin

mmDdpp ratio: 1/2 x 1/2 x 1/2 x 1/2 = 1/8

For plants with mottled leaves, dwarf height, peach skin

mmddpp ratio: 1/2 x 1/2 x 1/2 x 1/2 = 1/8

3 0

3 years ago

A female patient who is diabetic sustained an ST-elevation myocardial infarction (STEMI). The nurse provides discharge teaching.

Aneli [31]

Answer:

The options

A) "Medications are needed to prevent heart failure."

B) "I will take aspirin, atenolol, and captopril indefinitely."

C) "My blood pressure should be less than 130/80 mm Hg."

D) "Daily estrogen will prevent another heart attack."

The CORRECT ANSWER IS D)

D) "Daily estrogen will prevent another heart attack."

Explanation:

A reduction in the natural hormone estrogen levels could be a causative factor in heart disease increase within post-menopausal women. Estrogen is thought to show a positive impact on the inner layer of artery wall, functioning in such a way to keep blood vessels elastic.

In spite of the advantages of estrogen, the American Heart Association speaks against employing postmenopausal hormone therapy to decrease the likelihood of coronary heart disease or stroke as some research works have revealed that it vividly do not decrase the risk of heart attack but increases the likelihood of blood clots and stroke.

4 0

3 years ago

HELP HELP HELP PLZ!

Mekhanik [1.2K]

Hi,

Let us get an introduction of the problem first, Incomplete dominance is a pattern of inheritance in which, offspring from the cross of two parents shows a phenotype that is not like either parent but in between both.

For example: Let us take the example of Oompah's hair that can be either red or purple or blue. As described in the question, Red is dominant so let us denote allele for Red hair with R. The other hair color is blue that is recessive, let us denote its allele with r. Now, there is another intermediate phenotype that is purple, let us denote it with Rr because it is derived through a combination of R and r.

Now, here is the key for all possible genotypes and phenotypes of Oompahs. There are only three possible genotypes and phenotypes for the hair color.

Genotype: Phenotype

RR : Red hair

Rr : purple hair

rr : Blue hair

This is because no allele can fully express itself over the other. So is we cross a red hair Oompah with Blue hair Oompah, let us see what will happen:

RR x rr

Gametes: r and R

rr: Rr : Rr : RR

It means that 25 % of the offspring will have red hair, 50% will have contain purple hair and 25 % will have blue hair.

RR: Red hair 25%

Rr: Purple hair 50 %

rr: Blue hair 25%

Hope it helps!

8 0

4 years ago

A group of organisms of the same species that live together in the same place at the same time are called a/an

Usimov [2.4K]

It is called a population since they are all the same species

3 0

3 years ago

Read 2 more answers