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bazaltina [42]
3 years ago
8

Why were the rocks on the river bed smooth?

Biology
2 answers:
notsponge [240]3 years ago
8 0

because the water runs over them that, then makes them smooth.
JulijaS [17]3 years ago
4 0
The answer is actually the third one with the rushing water. The continuous flow of water down the stream gradually eroded away jagged parts of the rocks; this phenomena is actually what created the grand canyon. Over a long period of time, the flow of water can make lasting changes. 
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A survey reveals that 25 percent of a population of 1,000 individuals have attached earlobes (are homozygous recessive for the t
Mumz [18]

Answer:

d. pxp +2pq

Explanation:

The formula for genotype frequency for a population in Hardy-Weinburg equilibrium is as under:

                           p² + 2pq + q² = 1

where, p = dominant allele

           q = recessive allele

Here,

 p² represents frequency of homozygous dominant genotype

2pq represents frequency of heterozygous genotype

q² represents frequency of homozygous recessive genotype

Also, although the genotypes p² & 2pq are different from each other yet phenotypically they both will collectively produce dominant trait i.e. free ear lobes not attached earlobes. So the term "p² + 2pq or pxp + 2pq" represents the frequency of the individuals who show the dominant phenotype in this particular population. Dominant phenotype will comprise 75% of the population.

4 0
3 years ago
Martha is telling her teacher how an animal cell is like a house. Which part of the animal cell is like the doors and windows in
Elina [12.6K]
Cell membrane is like doors and windows!!

if you know how; comment !
4 0
3 years ago
Please help i will give you brainliest
Alenkasestr [34]
1)  Embryonic stem cells can become all cell types of the body because they are pluripotent (that means having the ability to originate almost every type of cell in the body). On the other hand, adult stem cells are more limited and can only differentiate into different cell types of the same tissue. For example, if the tissue is skin, they would differentiate in keratinocytes, melanocytes, etc. We can say that adult stem cells are multipotent because they can become more than one type of cell.

1.1
Advantages of embryonic stem cells:
-They can grow easily in culture
-Originate almost every type of cell in the body with the right stimuli
Advantages of adult stem cells:
-Adult stem cells that come from this patient and then are reintroduced in him are less likely to initiate rejection after transplantation.
- They are present in a lot of tissues/organs: bone marrow, brain, blood vessels, muscle, skin, heart, and many more.

1.2 Disadvantages of embryonic stem cells:
- They are obtained from human embryos and because of that they are destroyed during the process
-There is not enough information obtained to understand this cells completely.
Disadvantages of adult stem cells:
-It's difficult to isolate these cells from the rest of the tissue
It'sts not easy to have a big number of them in cell culture
(these are a problem because it needs to exist large numbers of these cells to be used in replacement therapy for this patient.)

2)
<span>The answer is: During differentiation, certain genes are activated to produce proteins that enable specific functions.
</span>During the differentiation process, some parts of the cell genome will be activated or expressed, while others parts will have it repressed. The part that was activated will lead to translated proteins that will help dictate the shape of the cell as well as their function. This is a process of gene expression and can be activated or repressed by stimuli from the inside or outside of the cell.

3. The answer that BEST explains is Meiosis results in offspring with genotypes that are not exact copies of the parents.
Something that differentiates meiosis from mitosis is the fact that the new cells have different genetic information due to the recombination of genetic material from the parents. This will make the offspring different from the parents. Also, a process that helps mixing the DNA is  Crossing over. Crossing over. is an exchange of DNA between homologous chromosomes (half are from the mother and the other half from the father).
4 0
3 years ago
If the temperature changes during a chemical reaction, what has occurred?
pogonyaev
A. energy was transferred  
3 0
3 years ago
A skin rash that neither itches nor burns is a symptom of which stage of syphilis?
iogann1982 [59]
This occurs in the first stage of secondary syphilis
7 0
4 years ago
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