Answer:
Contamination of the control sample (negative control) with DNA
Explanation:
The Polymerase Chain Reaction (PCR) is a technique widely used in molecular biology laboratories to amplify a target DNA fragment using primer pairs and DNA polymerase. In PCR experiments, it is imperative to include both positive and negative controls. The positive control refers to the amplification of a PCR product (amplicon) of known molecular size during PCR reaction in order to ensure the correct molecular weight of the target DNA fragment. The negative control refers to the inclusion of a sample without DNA in order to ensure that no contamination with DNA has occurred in the other samples.
Scientists have discovered that there are reproductive isolating mechanisms that can stop a population from interbreeding and possibly lead to the formation of a new species. What is this process called
Answer:
Polyploidy
Explanation:
The isolating mechanism that is capable of stopping a population from interbreeding, possibly leading to speciation is polyploidy.
Polyploidy is a condition in which a species of an organism will have multiple, instead of a diploid, chromosomal set as a result of an error during meiosis.
Non-disjunction during meiosis can make a gamete have a diploid number of chromosomes in the place of a haploid chromosome. A 2n gamete fusing with an n gamete will result in a triploid organism, 2n plus 2n gametes will result in a tetraploid organism, etc.
If the extra chromosomal set is from the same species, such polyploidy is termed autopolyploidy, otherwise, it is termed allopolyploidy. Having extra sets of chromosomes has the capacity to make an organism to be reproductively incompatible with normal diploid organisms of the same species. However, polyploid organisms can either self-pollinate or cross with another polyploid organism, a process that can lead to sympatric speciation.
Select all that apply to the evidence of evolution:
A homologies- anatomical, molecular, and developmental
B biography
C natural selection
D fossil record
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Answer:
B.
Explanation:
Select all the true statements about density: (hint - there are 4 correct statements)
d=m/v (denisty equals mass divided by volume)
density is measured in meters
density is the ratio of an objects mass to its volume
objects that are heavy for their size are very dense
objects that are heavy for their size are not dense
density is how much matter is in a given amount of space
all dense objects will float
(there is more then 1 answer by the way)
answer
2nd is wrong
5th is wrong
last is wrong
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A change in the nucleotide sequence
produced during DNA replication
DNA is a dynamic and adaptable molecule. As such, the nucleotide sequences found within it are subject to change as the result of a phenomenon called mutation. Depending on how a particular mutation modifies an organism's genetic makeup, it can prove harmless, helpful, or even hurtful.
CUCKOO AND WARBLER symbiotic relationship?
Answer:
The relationship between the Cuckoo Bird and the Warbler is a parasitic symbiotic relationship.
Explanation:
The Warbler lays their eggs in the Cuckoo bird's nests that their offspring can be cared for by the other bird. The Warbler benefits by not having to care for their young while the Cuckoo bird is harmed by having to care for the extra birds in their nests.
What are paired chromosomes called?
Answer:
Humans have 23 pairs of chromosomes--22 pairs of numbered chromosomes, called autosomes, and one pair of sex chromosomes, X and Y. Each parent contributes one chromosome to each pair so that offspring get half of their chromosomes from their
Measurements of physical ocean characteristics are often taken at the time and place of phytoplankton sampling.
a. True
b. False
What does ambulocetus translate to?
Ambulocetus (meaning "walking whale") is an early cetacean with short limbs and large feet used for swimming. Along with other members of Ambulocetidae, it is a transitional fossil that shows how whales evolved from land-living mammals.
Answer:
Walking whale that swims
Explanation:
its a cetacean with short limbs and large feet used for swimming
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Which of the following increases soil acidity?
planting acid-loving plants
adding compost
adding aluminum
acid rain
Answer:
acid rain
Explanation:
Answer: The correct answer is acid rain
Explanation: This answer has been confirmed correct.
Cross a person who does not have freckles and is heterozygous for dimples with a person who has
freckles (but her mom does not) but no dimples.
1. What is the probability that these parents will have a child with dimples?
2. What is the probability that these parents will have a child with freckles?
3. What is the probability that these parents will have a child with dimples and freckles?
Answer:
1. 1/2
2. 1/2
3. 1/4
Explanation:
Let the allele for freckles be A or a while that of dimples be B or b.
A person without freckles but heterozygous for dimples = aaBb
A person who has freckles (whose mother has no freckles) but no dimples = Aabb
aaBb x Aabb
Offspring
4 AaBb - freckled and dimpled
4 Aabb - freckled and non dimpled
4 aaBb - non freckled and dimpled
4 aabb - non freckled and non dimpled
1. Probability that the parents will have a dimpled child = 8/16 or 1/2
2. Probability that they will have a child with freckles = 8/16 or 1/2
3. Probability that they will have a child with freckles and dimples = 4/16 or 1/4
See the attached image for the Punnet's square analysis of the cross
Which of the following statements is true?
In humans, fertilization creates a cell with 23 chromosomes.
All organisms have the same number of chromosome pairs.
Females have a 100 percent chance of inheriting Y-linked genetic disorders.
Males are more likely to be colorblind because they only have one X chromosome.
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why do cells need to go through mitosis
Answer:
Mitosis is a way of making more cells that are genetically the same as the parent cell. It plays an important part in the development of embryos, and it is important for the growth and development of our bodies as well. Mitosis produces new cells, and replaces cells that are old, lost or damaged.
Explanation:
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During the cell cycle, the cell duplicates its genetic material. Moreover, also during this cycle, the cell synthesizes all materials required for its division.
The cell cycle can be divided into an interphase and a mitotic (M) phase.
The interphase is in turn divided into three phases: Growth 1 (G1) phase, Synthesis (S) phase and Growth 2 (G2) phase.
During the S phase, the cell duplicates its genetic material by a process called DNA replication.
During G1 phase and G2 phase, the cell grows and synthesizes all materials (i.e., proteins) required to enter into the M phase.
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