Changing only one variable at a time is a rule for conducting a controlled
experiment.
Controlled experiment involves the use of dependent and independent
variables . Changes in the independent variable brings about a
corresponding change in the dependent variable which is then recorded.
It is however important to note that changing more than only one variable at
a time won't accurately determine if the changes in the results were as a
result of one cause. This is why only one variable has to be changed at a
time.
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Viruses can not grow in nutrient media. Why ?
Answer:
Viruses are obligate intracellular parasites and cannot grow on inanimate media. They need living cells for replication, which can be provided by inoculation in live animals among other methods used to culture viruses (cell culture or inoculation of embryonated eggs).
Describe the three methods for harvesting stem cells, for each method, explain the benefits of the method and the ethical concerns related to the method
Answer: These stem cells are manipulated to specialize into specific types of cells, such as heart muscle cells, blood cells or nerve cells. The specialized cells can then be implanted into a person. For example, if the person has heart disease, the cells could be injected into the heart muscle.
Explanation: Describe the three methods for harvesting stem cells, for each method, explain the benefits of the method and the ethical concerns related to the method
Stem cells are specialized cells that can proliferate into many types of cells lineages. Umbilical cord blood collection, bone marrow harvesting and dental pulp collection are the methods.
What are stem cells harvest methods?Stem cells can be collected from the blood and the tissues of the umbilical cord of the baby born and is an easy method that collects the cells from the umbilical cord and the placenta for future use.
The cells and the tissues are chopped and kept in the low temperatures that include the Mesenchymal stem cells in it. They are beneficial as they can treat cancers, anaemia etc. There are not many ethical issues related to umbilical cord use.
Stem cells can be derived from the bone marrow as this is the site where they originate from. The method uses the removal of the bone marrow from the pelvic bones and subjects them to the removal of the stem cells from the blood.
Stem cells from the bone marrow are used for the replacement of damaged cells. The use of the bone marrow and using human lives is the ethical issue concerned with bone marrow based stem cells.
The dental pulp collection method of the stem cells uses the method of deriving cells from the teeth region and are a source of the bone and the mesenchymal cells.
DPSCs can be used for cell banking and are the method that has no ethical concerns. It is simple can be done in dental routines.
Therefore, umbilical cord, dental pulp and bone marrow are the stem cells collection methods.
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What is mars' origin of the name?
Answer:
Mars was named by the ancient Romans for their god of war because its reddish color was reminiscent of blood
Explanation:
Solar radiation can cause skin cancer in an individual. If a man with skin cancer caused by solar radiation has offspring, which of the following statements would be true? A. only the man getting skin cancer would be affected B. only the man and his male offspring would be affected C. only the man and his female offspring would be affected D. the man and all of his offspring would be affected
Choose ALL of the correct answers.
Which of the following must be true in order for natural selection to occur?
Group of answer choices
There must be variation in traits in the population
The trait must cause the individual to evolve
The trait must have no other advantage in fitness
The trait must be for the good of the species
The trait must be heritable
The trait must advance the goal of evolution
Answer:
For natural selection to occur, it is true that there must be genetic variation in the population.
Explanation:
According to evolution, natural selection implies the changes that occur in the genotype of a species, due to the effect of environmental factors, and which guarantee its survival through adaptive evolution.
For natural selection to occur, three fundamental conditions must exist:
A trait that can be inherited from one generation to another.
The trait is subject to variability between subjects of the same species.
Genetic variability can determine the possibility of reproductive success and survival.
Therefore, a necessary factor for natural selection to occur is that genetic variability exists in the population.
For natural selection to occur :-
There must be variation in traits in the population.The trait must cause the individual to evolve.The trait must be for the good of the species.The trait must be heritable.The trait must advance the goal of evolution.What is Evolution?It is the change in the characteristics of a species over several generation.It relies on the process of natural selection.
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You advise your pregnant friend to give her cat away becauseA. She could contract plague.B. She could give the cat tularemia.C. She could get toxoplasmosis.D. She could get listeriosis.E. You do not like cats and want to see your friend without one.Reset Selection
Answer:
c. she could get toxoplasmosis
Explanation:
she would be exposed to cat litter; cat litter usually carries those parasites that cause toxoplasmosis.
Can Glucose turn into fat
Answer:
yea
Explanation:
If u consume to much or have diabetes its cant run it so it turns into fat
scientists have discovered a mutation that prevents the formation of which are responsible for separating chromosomes
The chromosomes are separated by a structure called the mitotic spindle. The mitotic spindle is made of many long proteins called microtubules, which are attached to a chromosome at one end and to the pole of a cell at the other end. The sister chromatids are separated simultaneously at their centromeres
In a population of cattle, the average body fat percentage is 10.5%. You select parents with an average body weight percentage of 20.8%. The offspring they produce have an average body weight percentage of 17.6%. Based on these data, what is the narrow-sense heritability of this trait
Heritability in the narrow sense -h²- refers to the proportion of the phenotypic variability that is influenced by genetic factors. In the exposed example, the narrow-sense heritability of this trait is h² = 0.689 ≅ 0.7
-----------------------------
Before answering the question, let us first review a few concepts.
The selection differential, SD, is calculated by getting the difference between the mean value of the desired trait in the population (X₀) and the mean value of the same trait expressed by parents, (Xs). So,SD = Xs - X₀
Heritability in the narrow sense -h²- is the measure of the genetic component to which additive genetic variance contributes.It referes to the proportion of the phenotypic variability that is influenced by genetic factors.
The heritability might be used to determine how the population will respond to the selection done, R.
h² = R/SD
The response to selection (R) refers to the metric value gained from the cross between the selected parents. R can be calculated by multiplying the heritability h² with the selection differential, SD.R = h²SD
R also equals the difference between the new generation phenotypic value (X₁) and the original population phenotypic value (X₀),
R = X₁ - X₀
Now that we know these concepts and how to calculate them, we can solve the proposed problem.
Available data:
Population average body fat ⇒ 10.5% ⇒ X₀ Selected parents average body weight ⇒ 20.8% ⇒ XsOffspring average body weight ⇒ 17.6% ⇒ X₁We ned to get the narrow-sense heritability of this trait, h².
h² = R/SD
R = X₁ - X₀ = 17.6% - 10.5% = 7.1%SD = Xs - X₀ = 20.8% - 10.5% = 10.3%
h² = R/SD = 7.1% / 10.3% = 0.689 ≅ 0.7
The narrow-sense heritability of this trait is h² = 0.689 ≅ 0.7
-------------------------------------
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Natural selection, adaptations, genetic variation, and population evolution are all related in terms of changes in phenotypes over
time. Evaluate which statement appropriately describes the relationship between the concepts of natural selection, adaptations,
genetic variation, and population evolution and select the best choice.
A)
8)
Genetic variation exists in a population. Some of the genetic variation
results in different phenotypes. The phenotypes that enhance survival are
called adaptations. Individuals with well-adapted phenotypes are more
Likely to survive and reproduce, leading to population evolution over
generations.
Adaptations exist in certain individuals in a population. The increase in
adaptations causes an increase in genetic variation. The adaptations that
enhance survival lead to larger populations, which further increases
genetic variation. Individuals with well-adapted phenotypes are more
Likely to survive and reproduce, leading to population evolution over
generations.
Genetic variation is high in a population, but random events cause it to
decrease. Populations with fewer individuals and lower genetic diversity
are able to undergo natural selection when selective pressures are high.
The increase in selective pressure causes an increase in adaptations that
are better suited for survival This results in an evolutionary change of a
population
Selective pressures exist in nature and cause changes in a population.
Populations with high selective pressures have higher rates of genetic
change, leading to an increase in genetic variation, Increased genetic
variation leads to some individuals having well-suited adaptations. The
presence of these new adaptations is evidence that the population has
changed, or undergone evolution
o
D)
Answer:
A is the answer
Explanation:
I'm just guessing
Genetic variation exists in a population. Some of the genetic variation results in different phenotypes. The phenotypes that enhance survival are called adaptations. So, the correct option is A.
What is Genetic variation?Genetic variation among members of the same species is called genetic variation. This variation may be due to variations in gene expression, DNA sequence and epigenetic changes. Mutation, genetic recombination, and genetic drift are causes of genetic variation, which can be altered by environmental variables including exposure to chemicals or climate changes.
Genetic diversity is important because it gives natural selection a starting point to work from, helping organisms to adapt and change over time. There is genetic diversity within a population. Different phenotypes are the result of some genetic variation. Adaptations are traits that improve survival.
Therefore, the correct option is A.
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Your question is incomplete, most probably the complete question is:
Natural selection, adaptations, genetic variation, and population evolution are all related in terms of changes in phenotypes over time. Evaluate which statement appropriately describes the relationship between the concepts of natural selection, adaptations, genetic variation, and population evolution and select the best choice.
1. Genetic variation exists in a population. Some of the genetic variation results in different phenotypes. The phenotypes that enhance survival are called adaptations. Individuals with well-adapted phenotypes are more likely to survive and reproduce, leading to population evolution over generations.
2. Adaptations exist in certain individuals in a population. The increase in adaptations causes an increase in genetic variation. The adaptations that enhance survival lead to larger populations, which further increases genetic variation. Individuals with well-adapted phenotypes are more Likely to survive and reproduce, leading to population evolution over generations.
3. Genetic variation is high in a population, but random events cause it to decrease. Populations with fewer individuals and lower genetic diversity are able to undergo natural selection when selective pressures are high. The increase in selective pressure causes an increase in adaptations that are better suited for survival This results in an evolutionary change of a population.
4. Selective pressures exist in nature and cause changes in a population. Populations with high selective pressures have higher rates of genetic change, leading to an increase in genetic variation, Increased genetic variation leads to some individuals having well-suited adaptations. The presence of these new adaptations is evidence that the population haschanged, or undergone evolution.
Question 1) Discuss how compounds in different types of organisms can be used to benefit people? ( Will Mark Brainliest).
Answer:
Compounds from different organisms are being used widely bu humans for their benefits. Some of the compounds are used as drugs. For example, penicillin is used as a drug or antibiotic. There are many plants which provides humans with other types of medicines and herbal remedies. There are other compounds which are used for cancer treatment. For example, taxol is a compound obtained from trees which are being used as anticancer drugs.
Explanation:
If a nucleus has eight chromosomes following replication, how many chromatids does it have?
Answer:
It has 16 chromatids
Explanation:
Since each chromosome has 2 chromatids
why do the scientists feel comfortable with calling the hybrids a new species
Answer:
1 . They have the potential to interbreed in nature . 2 . They can produce viable offspring if they do interbreed—that is, their offspring are healthy enough to produce offspring of their own . and also its new,
Explanation:
the enteric nervous system is a network of neurons found throuout the wall of thoracic orgsns such as the lungs. true or flase
Answer and Explanation: The answer is false, as it is a network of neurons, however it is embedded in the wall of the gastrointesinal system.
narvez 5. Everyone in Dobby's family has a long nose and they brag that they are from a purebred line. Viola has a stubby nose. Draw a punnett square to determine the possible types of noses their children could have had. (Use the genotypes from #2) a. List the possible genotypes and phenotypes for their children. b. What are the chances of a child with a long nose? out of or % c. What are the chances of a child with a stubby nose? out of st or__% d. Would their children be considered purebred like Dobby? Explain:
Assuming a single diallelic gene coding for the trait and expressing complete dominance, the phenotypes, genotypes, and probabilities of getting each of them vary according to the parentals' genotypes. See the options below.
---------------------------------
Since I do not have the genotypes from #2, I will provide different potential scenarios for this question.
I advise you to check on them and see which one matches the genotype from #2.
Let us assume a single diallelic gene is coding for the trait and expresses complete dominance.
SCENARIO 1 ⇒ long nose is the dominant traitLet us say that
L is the dominant allele and codes for long nosel is the recessive allele and codes for stubby noseSince long nose is dominant over stubby nose
LL and Ll ⇒ long nosell ⇒ stubby noseIf Dobby comes from a purebred family and has long nose, his genotype must be LL.
And if Viola has stubbi nose, her genotype must be ll.
Cross 1
Parentals) LL x ll
Gametes) L L l l
Punnett square) L L
l Ll Ll
l Ll Ll
F1) Genotype ⇒ 100% heter0zyg0us Ll
Phenotype ⇒ 100% long-nosed
There is 100% chances for a child to have a long noseThere is 0% chances for a child to have a stubby noseThese children are not purebred**********
SCENARIO 2 ⇒ Stubby nose is the dominant traitLet us say that
S is the dominant allele and codes for stubby noses is the recessive allele and codes for long noseSince stubby nose is dominant over long nose
SS and Ss ⇒ stubby nosess ⇒ long noseIf Dobby comes from a purebred family and has long nose, his genotype must be ss.
And if Viola has stubbi nose, her genotype must be either SS or Ss.
There are two possible crosses.
Cross 1 : Violet is h0m0zyg0us dominant SS
Parentals) SS x ss
Gametes) S S s s
Punnett square) S S
s Ss Ss
s Ss Ss
F1) Genotype ⇒ 100% heter0zyg0us Ss
Phenotype ⇒ 100% stubby-nosed
There is 100% chances for a child to have a stubby noseThere is 0% chances for a child to have a long noseThese children are not purebredCross 2: Violet is heter0zyg0us, Ss
Parentals) Ss x ss
Gametes) S s s s
Punnett square) S s
s Ss ss
s Ss ss
F1) Genotype ⇒ 50% heter0zyg0us Ss and 50% h0m0zyg0us recessive ss
Phenotype ⇒ 50% stubby-nosed and 50% long-nosed
There is 50% chances for a child to have a stubby noseThere is 50% chances for a child to have a long noseThese children are not purebred----------------------------
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Which organelle is only
found in plant cells?
A. chloroplasts
B. cell membrane
C. nucleus
D. mitochondria
Answer:
Chloroplasts Is the answer you are looking for.
Hope this helps!
The following image gives a basic diagram of a typical moss plant. Label some of the important parts of the plant, and identify which structures represent the sporophyte and gametophyte phases.
An illustration shows a moss plant. The leaf-like parts and rhizoids are labeled as C and D respectively. Together they are labeled as B. The top portion of the plant is labeled as A.
Need answers for A,B,C,D I have included the multiple choice answers below.
Answer:
for the first one its the second one i could not see the others
Explanation:
Select the TRUE statement about a resting neuron. a.) The cytoplasm side of a neuron is positively charged while the outside of the neuron has no charge. b.) The cytoplasm side of a neuron is negatively charged while the outside of the neuron is also negatively charged. c.) The cytoplasm side of a neuron is more negative than the outside of the neuron. d.) The cytoplasm side of a neuron is more positive than the outside of the neuron.
Given what we know about the nervous system and resting neurons, we can confirm the cytoplasm side of a resting neuron is more negative than the outside of the neuron.
What is a neuron?Neurons are specialized cells that make up the nervous system in the body. Their primary function is to act as messengers, delivering information in the form of electrical impulses and neurotransmitters. These neurons work using rapid shifts in membrane potentials.In order to do this, the starting value or resting point of the membrane is negatively charged.Therefore, we can confirm that since neurons function using shifts in membrane potentials, the starting point or resting form of a neuron has a negatively charged membrane, meaning that the cytoplasm side of a resting neuron is more negative than the outside of the neuron.
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Could there be winds without differential heating? Using evidence from Unit 5 explain what differential heating is and whether this effects the earth’s global wind patterns.
HELPPP PLEASE SITE EVIDENCE (WILL MARK BRAINLIEST)!!!!!!!!
Differential heating is responsible for the wind patterns across the globe.
Differential heating is defined as the difference in heating of air on the land versus water. Sea breezes occur when land heats up faster than water which rises and creates a low pressure system. The high pressure air from the sea influxes is responsible for the creation of a sea breeze.
Unequal heating of the Earth's surface is responsible for the formation of large global wind patterns. Warm air rises at the equator and moves toward the poles while on the other hand, the cooler air rises at the poles and moves back toward the equator so in this way the earth’s global wind patterns occurs so we can say that differential heating is responsible for the wind patterns across the globe.
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Human embryonic development is the development and formation of the human embryo. It is characterized by the process of cell division and cellular differentiation of the embryo that occurs during the early stages of development. In biological terms, the development of the human body entails growth from a one-celled zygote to an adult human being. Choose ALL of the statements that correctly describe stages in human embryology and gestation.
The normal period of gestation is about 40 weeks.
The germinal stage refers to the time from fertilization through the development of the early embryo until implantation is completed in the uterus in about 21 days.
The stages of human development include, in order: zygote, blastocyst, embryo, and fetus
A blastocyst, if untouched and allowed to remain implanted, will eventually develop into a morula.
Changes to the form of the embryo come from differentiation and growth.
The statements that correctly describe gestation are: the normal period of gestation is about 40 weeks; the stages of this process include: zygote, blastocyst, embryo, and fetus; and changes to the form of the embryo come from differentiation and growth.
The gestation period in humans lasts about 40 weeks and comprises different stages and processes from conception until birth. The main stages of this process include:
Zygote: Fertilized ovum.Blastocyst: Cluster of cells that is the result of the zygote going through cell division.Embryo: Unborn human that is still developing, usually before the 8th week of gestation.Fetus: Unborn human in development after the 8th week of gestation.Moreover, this process implies differentiation as cells specialize for specific functions, for example, muscle cells or nerve cells, and growth as the number of cells increases and therefore the embryo or fetus increases in size.
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Answer:
Many different types of cells make up the human body. Therefore, it is important for cells to differentiate to form different types of tissue. The tissue can then combine to form different organs and systems that carry out specialized functions for the human body.
Explanation:
Did the predators prey on the two variations of moths equally?
Answer:
This is true.
Explanation:
I did the test.
Are gender traits completely a result of societal expectations?
Are there any parts of the human body that get oxygen directly from the air and not from the blood?
Answer:nope there are no parts like that.
Explanation:
our body uses energy in the form of ATP which is a by product of respiration.
Glucose molecue is broken down into water and ATP molecule.
So our body only take oxygen from blood.
We don't have stomata all over our body dude!
How do you think scientists figure out the life cycle of a star
Answer:
space
Explanation:
they figured it out going to space and since a star is a small peice of the sun they can't touch it it's impossible without getting heat burns or dying so they ither observe a star using a telescope or went to space for days
1
Which two ways do the black-tailed jackrabbit and the kit fox interact with the
desert environment?
Select two correct answers.
A
Black-tailed Jackrabbits and Kit Foxes interact with the desert
environment by providing food for plants.
Black-tailed Jackrabbits and Kit Foxes use water and air from the
environment to survive.
B
>
с
Black-tailed Jackrabbits and Kit Foxes obtain energy from consuming
other organisms.
Black-tailed Jackrabbits and Kit Foxes consume plants but do not
need the environment for survival
D
E
Black-tailed Jackrabbits and Kit Foxes meet their needs in their
environment by eating only plants for food.
Answer:
b
Explanation:
Select ALL the correct answers.
A mother has blood type A and her son has blood type O. Which blood types are possible for the father?
A
O
AB
B
Answer: Blood types O, A, and B are possible for the father.
Explanation: Since the mother has type A blood, there are two possible genotypes that she can have: AA or AO. Since her son has type O blood, he only has one genotype: OO.
For blood types,
Type A - AA or AO
Type AB - AB
Type B - BB or BO
Type O - OO
* A and B are dominant over O.
Now we have to do crosses between the mother and the father:
AA mother with AB father: child with type AA or type AB blood
AO mother with AB father: child with type AA, AO, AB, or BO blood
AA mother with OO father: child with AO blood
AO mother with OO father: child with AO or OO blood
AA mother with AA father: child with type AA blood
AA mother with AO father: child with type AA or AO blood
AO mother with AA father: child with type AA or AO blood
AO mother with AO father: child with type AA, AO, or OO blood
AA mother with BB father: child with type AB blood
AA mother with BO father: child with AB or AO blood
AO mother with BB father: child with AB or BO blood
AO mother with BO father: child with AB, AO, BO, or OO blood
The father can have blood types O, A, or B.
Which of the following is a correct association?
Answer:
The first one
Explanation:
because it has the most words on their.
The correct association is option a.The cell synthesises proteins and organelles in the G2 phase (also known as the "Gap 2 phase") of the cell cycle in order to prepare for cell division.
The cell enters the G2 phase following DNA replication, which takes place during the S phase. In order to manufacture the elements required for cell division, the cell continues to expand and goes through further protein synthesis during this phase. These proteins play a role in the development of the mitotic spindle, control of cell cycle checkpoints, and cytoskeleton organisation.
The cell also creates organelles like the mitochondria and endoplasmic reticulum to make sure there will be enough energy and cellular building blocks for the impending division in the phase.
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Which of these is a compound?
Answer:
your anwser would be sugar please mark brainliest
Explanation:
Answer:
I think it's sugar.
Explanation:
It is formed by a combination of three atoms: carbon, hydrogen and oxygen.
A control can be best defined as:
A) a variable that is kept constant in an experiment
B) an experiment where the final results are known ahead of time
C) a hypothesis that regulates the results of an experiment
D) an experiment that is undertaken both in the field and in the laboratory
E) a variable that changes during the course of an experiment
Answer:
A) a variable that is kept constant in an experiment
Jennipher was asked by her mother to take a certain kind of fish in a bucket full of water so that she can prepare it for meal.when jenipher touched the fish she felt like an electric shock to her hand. what behavioural mechanism did the fish generate?
The fish use reacting behavioural mechanism in order to protect itself from the danger.
The fish uses reacting behavioural mechanism when the fish sense any type of danger surrounds it. This behaviour is a type of defense mechanisms which is used to defend and protect itself.
The fish apply electric shock in order to protect itself from the attackers and give harm to the other organisms which comes in contact with it so we can conclude that the fish use reacting behavioural mechanism in order to protect itself from the danger.
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A researcher sequences the genome of a variety of bacterial and eukaryotic cells. She finds that the bacterial genome is smaller, but that there are more genes for a given number of base pairs in the eukaryotic cells. In other words, there are fewer genes per unit of length of DNA in the eukaryotic cells. What do you predict she will find if she examines the DNA more closely
From this observation, it is possible to conclude that there are more repetitive sequences in the eukaryotic DNA than in the bacterial DNA. Prokaryotic genes do not contain introns.
Introns are internal non-coding segments of eukaryotic genes that must be removed to produce the final mature mRNA.
In prokaryotic genomes, there are no introns, and genes are expressed in groups known as operons.
Eukaryotic genomes contain highly repetitive intergenic (regulatory) and intragenic (introns) non-coding regions.
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