In directional selection, a population's genetic variance shifts toward a new phenotype when exposed to environmental changes. Diversifying or disruptive selection increases genetic variance when natural selection selects for two or more extreme phenotypes that each have specific advantages.
Answer:
Species selection
Explanation:
Just took the test
With the aid of a sketch. Describe foetal circulation
Answer:
In animals that give live birth, the fetal circulation is the circulatory system of a fetus. The term usually encompasses the entire fetoplacental circulation, which includes the umbilical cord and the blood vessels within the placenta that carry fetal blood.
Blood flow in the unborn baby follows this pathway: Oxygen and nutrients from the mother's blood are transferred across the placenta to the fetus through the umbilical cord. This enriched blood flows through the umbilical vein toward the baby's liver. There it moves through a shunt called the ductus venosus
Via the mother's cardiovascular system and the ________ , the respiratory system supplies oxygen to and removes carbon dioxide from the blood of a developing fetus.
Answer:
The mother's cardiovascular system and the placenta.
Explanation:
Babies receive their oxygen and get rid of the carbon dioxide with the help of both the cardiovascular system of the mother and the placenta. The gases dissolve through the placenta and then gets exchanged in the cardiovascular system of the mother. So the answer is the mother's cardiovascular system and the placenta.
I hope this answer helps.
PLEASE HELP ME ASAP BECAUSE IT IS DIFFICULT TO UNDERSTAND. Explain it for me.
Answer:
C.
Explanation:
For mRNA strands, there are four letters used in their code. A (adenine), U (Uracil), G (guanine), and C (cytosine.)
For RNA, it is the same, but the Uracil is replaced with Thymine (T).
A always pairs with U.
G always pairs with C.
YOUR QUESTION:
The scientist's strand code is has to convert the Thymine to Uracil since it is RNA instead of mRNA.
Hopefully this somewhat helped :)
The uterine cycle describes the cyclic changes of thickening and degeneration that the endometrium goes through in a month. What is the order of events in one uterine cycle
Answer:
During the uterine month there are different phases through which the uterus passes, these phases are regulated by hormones and are responsible for producing the cycle necessary for fertilization.
Phase where menstruation occurs: This phase only happens if the woman was not fertilized and did not develop the diploid cell together with a sperm, since not being fertilized, all the uterine preparation that had been planned in the body for fertilization will be released as that we know "menstruation", in this phase estrogens and progesterone are low. The inner walls of the unfertilized uterus are released.
Follicular phase, in the follicular phase the ovaries prepare to release an egg and estrogen begins to rise. (From the first day of the period until ovulation)
Proliferative phase, in the proliferative phase, new vessels proliferate and the outermost layer of the uterus prepares itself for possible fertilization, is where spiral arterioles can begin to form again in the external cut of the myometrium.
Ovulation, here is where the mature ovum is called Graff's follicle, at this time estrogen reaches its peak and then descends.
Luteal phase, in the luteal phase the production of the luteal body is generated, at this stage progesterone takes center stage, and it is the range between ovulation and menstruation (if not fertilized)
Last phase, secret phase, in this phase there are two possible ends, if the woman is fertilized, the egg cell implants and begins the development of the embryo and if it is not fertilized, the entire external cut of the myometrium is prepared to be secreted.
Explanation:
A very important fact to clarify is that women are born with a quantity of ovules that at the end of this uterine cycle ceases to exist, this process is what we know as menopause.
That is to say that women have a quantity of ovules that will one day run out, and the body releases them from the menarche or the first menstruation, generating that in each released ovule a uterine cycle is completed, the day they end the woman will have reached menopause and would have no chance of being fertilized or completing the uterine cycle.
superficial layer of the endometrium is shed
basal layer of endometrium grows, forms gland and blood vessels
enriched endometrial blood supply
endometrial glands secrete nutrients into uterus
You observed many sand hill cranes on your walk. Two sand hill cranes flapped their wings and hopped up and down when you walked on the path near where their bright orange baby stood. You observed a(n) _______________.
Answer:
This question lacks options, the options are:
A) symbiosis
B) ecosystem
C) community
D) population
E) biosphere
The answer is D) Population
Explanation:
Living organisms in an ecosystem are usually found in numbers living together in a given area. This is termed POPULATION in ecology. A population refers to the group of living organisms that belongs to the same species living together in the same habitat and have the ability to interbreed i.e. mate and reproduce with one another.
This is the case in this question where many sandhill cranes (large flying birds) were observed in a particular area, which represented their habitat. Asides the group of sandhill cranes living together, they were also observed to be interbreeding. This was evident in the observation of two sandhill cranes hopping up and down around their bright orange baby. This shows that members of the population are capable of mating and reproducing fertile offsprings.
This observation completes what a POPULATION is all about, hence, a population was observed.
Explain three ways in which the human
sperm cell is adapted to its function.
1) Sperm cell is adapted to its function by carrying genetic information to an egg.
2) It has a stream lined body that allows it to move quickly.
3) They also contain large number of mitochondria in the mid region, so it is able to produce a lot of energy in order to operate tail
In most mammals, the embryo obtains food substances from the mother via the
O Yolk
O Amnion
O Placenta
Uterus
Explanation:
it is through the placenta.
it also protects the embryo from harmful substances
The leaves of both monocots and dicots contain different tissues in a different organization than in the stems and leaves, but again, share many similarities. View the photos of a generalized plant leaf in the provided PowerPoint to answer the following questions. (12 points possible, 6 points each part) a. What function do the leaves of plant serve in supporting its survival and reproduction? Describe at least two important functions of leaves. b. Describe in your own words two unique cell types or tissue types we only see in plant leaves. How do they support the survival of the plant?
Answer:
Leaf are usually flattened green extension from the stem of a vascular plant.
a) Leaves functions :
- primary sites of photosynthesis and produces food for plants.
- leaves are an essential part of stem system and connect through vascular system to the rest of the plant so that free movements and exchange of nutrients, water and end products of photosynthesis.
b) leaves are differentiate into three types of tissues: dermal tissue, vascular tissue, and ground tissue. Dermal tissue protects the plant, and controls gas exchange in leaves, vascular tissues helps in translocation of nutrients and water.
Even though cannabis use is legal in some states, it may not be allowed on a college campus in those states because:
Answer: well you can consider half of the college campus population as underage. So the distribution to monitors would be easier. Making it illegal is just easier
Explanation:
A biologist is in the process of classifying a newly discovered fungus. The fungus is a decomposer and has saclike structures. The organism most likely belongs in the same group as which of the following? fungi that are rusts fungi that are associated with bread mold fungi that makes blue cheese fungi that are autotrophic decomposers
Answer:
fungi that are associated with bread mold
Explanation:
Bread mold fungi are fungi, they grow where there is moisture and organic food substance.
Bread mould are formed from mould spores that grows usually on bread surface especially when exposed
they feed on the organic substance found in the bread such as carbohydrate. Bread mould grow within 5-7days.
Answer:
b. fungi that are associated with bread mold
Explanation:
Albumin is a protein found in blood that helps to regulate amount of fluids in the body. What is the main function of albumin?
to provide structure
to fight disease
to maintain homeostasis
to regulate cell reactions
Answer: c.) to maintain homeostasis
Explanation: you're welcome!! cx
Answer:
C
Explanation:
Edge2020 quiz
10 Points
Which of the following statements is TRUE:
A. Plants are single celled, animals are multicellular, both are eukaryotes
B. Plants and animals are eukaryotes and multicellular
C. Plants are eukaryotic, animals are prokaryotic
D. Plants and animals are prokaryotes and multicellular
Reset Selection
Answer:
Option B is the correct answer.
Because they both are multicellular and eukaryotes.
Those organism which are composed of multiple no. cell is called multicellular organism. Those organism which have their cells composed of all cell organelles and nucleus is bounded by nuclear membrane is called eukaryotes.Hope it helps...
Answer: B
Explanation: They are both multi-cellar(having more than one cell)
Also they are both eukaryotes meaning that they both have a nucleus.
what is DNA explain the concept of DNA and RNA
Answer:
DNA is the abbreviation of deoxyribonucleic acid, while RNA stands for ribonucleic acid. Both the RNA and DNA carry certain genetic information, however, there is some difference between the two. DNA comprises sugar deoxyribose and RNA comprises sugar ribose. DNA is found to be stable under alkaline conditions, while RNA is not stable.
DNA is a molecule having double strands, while RNA is a single-stranded molecule. There is a slight difference in the base-pairing found in the two nucleic acids. In DNA, the bases present are adenine, thymine, cytosine, and guanine. While RNA utilizes adenine, uracil, cytosine, and guanine bases. Both RNA and DNA perform distinct roles in humans. RNA codes for amino acids and functions as a messenger between the ribosomes and the DNA to produce proteins. While DNA is accountable for storing and conducting genetic information.
Explain the mechanism responsible for summation of contractions and the increase in height of contraction when the stimulus frequency is increased.
Answer:
The higher the stimulation frequency, the contractions will be more continuous and even additive.
Continuous stimuli reactivate muscle contraction once the action potential cycle is complete.
Explanation:
Muscle contractions can be continuous or cumulative once the action potential curve drops, since the action potential at the top of the mountain is in a refractory period.
I knit a graph of what cumulative contractions are like due to continuous stimulation.
In the graph I leave you pointed out some references:
mr = refractory moment
mnr = non-refractory moment (where the new stimulation is accepted and a more powerful cumulative muscle contraction is generated)
PA = potential for muscle action or contraction itself.
Help can you pls number 2 to 4
Answer:
Hey there!
1. Load
2. Broom
3. Flagpole
Hope this helps :)
How do plants get the nitrogen they need?
A.
From bacteria living in their roots
B.
From the air
C.
Directly from the soil
D.
Through photosynthesis
What is produced when cells differentiate?
•proteins
•hormones
•uniform cells
•specialized cells
Answer:
specialized cells
Explanation:
i believe is the answer
A 26-week-old baby was brought to the pediatric clinic because of increasing lethargy and cyanosis. The infant has been in good health at birth, and the mother had attempted breast-feeding. A blood sample was collected and a positive test for methemoglobinemia was obtained. The baby then was treated with intravenous ascorbate and methylene blue. Within 2 days the child was alert, and the cyanosis had disappeared. It is known that methemoglobin has absorption spectra maxima at 500 nm and 631 nm.
Answer the following questions:
a. What is the chemical difference between hemoglobin and methemoglobin, and how do their oxygen capacities compare?
b. How do you analyze the sample blood to detect methemoglobin?
c. What is the cause of the cyanosis associated with toxic methemoglobinemia?
d. What is the biochemical basis for treatment of toxic methemoglobinemia with ascorbate and methylene blue?
Answer:
a,
This is due to differences in the oxidation states of Fe. atoms present in the two protein pigments.
Generally,the Fe2+ atom in the heme groups is responsible for the oxygen carrying capacities of haemoglobin in RBC.However,in +2 state that Fe carry oxygen through cooperative binding in the blood.When methemoglobin is formed the Fe exits in +3,and therefore can not bind oxygen. Methemoglobin is a mettaloprotein of Fe3+ states. It results from the oxidation of Fe atoms in Hb from Fe2+ to Fe3+ states,during exposure to certain medications,and some nitrate,certain dyes and some compounds.
This can be conducted with CO-oximeter.This is a device used to measure the blood percentage oxygen saturation levels.It conduct this by measuring the oxygen carrying capacity of haemoglobin in a blood sample. Since oxygen saturation levels of a blood sample depends on the amount of Hb,therefore by passing some wavelengths of light across the blood samples,The more the wavelength of lights absorbed by the blood samples, the more the percentage saturation of the blood sample with oxygen,and therefore the oxygen carrying capacity of the blood,thus more Hb.
Hence, if the blood sample absorbs wavelength of light in the range of (500 nm and 631 nm.) it shows that little Hb is present in the blood samples,and the blood should contain Methemoglobin of Fe3+ and not Hb.
Methemoglobinemia is a condition in which methmoglobin concentration of the blood rises,due to the higher percentage of Hb,with F3+( of poor oxygen carrying capacity or uncoupling ) compare to normal F2+ for carrying oxygen. Since these can not transport oxygen,Cyanosis results as the baby turns blue,with lack of oxygen.
Since the rise in the concentration of methmoglobin is the major cause of this condition,reduction of it concentration is the primary step.Therefore, the Methylene blue role is to reduce the amount of methmoglobin by enzyme NADPH-methemoglobin reductase.This occurs with 10-60mints after administration.Thus the concentration of these pigment is reduced,likewise its toxic levels.
Ascorbate can also be used,however a lot of doses is required for this to have a significant effects,and compare to Methylene blue it is less effective.,
Explanation
At low frequencies during DNA replication, an extra nucleotide maybe inserted into the DNA strand. If this occurs within a gene, what would be the effect on the protein product
Answer:
1. It could result in a loss of function of the protein product
2. It could result in a protein product with excessive activity
3. It could result in altered structure of the protein
Explanation:
Any changes that occur in the nucleotide sequence in the DNA of an organism is known as a mutation. Various forms of mutation can occur in the DNA sequence of an organism which could be as a result of insertion or deletion of a nucleotide in the DNA sequence.
Insertion of an extra nucleotide into a DNA strand within a gene could have any of the following effects on the protein protein;
1. It could result in a loss of function of the protein product of the gene whereby the protein can no longer carry out its normal functions
2. It could result in a protein product with excessive activity other the normal range at which it functions.
3. It could result in altered structure of the protein either in the primary, secondary, tertiary, or quaternary structure
Jayden is raised in a culture where girls are not expected to like math or do well at math. Jayden therefore rarely studies for tests and in middle school, her test scores begin to drop below the average. In high school, she ends up taking the lower-level math courses. Which theoretical concept does this example illustrate? A. cognitive dissonance B. the self-fulfilling prophecy C. the actor-observer discrepancy D. the fundamental attribution error
Answer:
THE SELF FULLFILLING PROPHECY
Explanation:
BRAINLIEST PLS
Fur color in mice is affected by a gene with two alleles. The B allele causes dark brown fur and is completely dominant over the b allele that causes light brown fur. What is the fur color of a mouse with the genotype, Bb
Answer:
Since this is heterozygote dominant state(Bb), and B allele is dominant over the b allele brown(b) ,hence the fur color must belong to the dominant allele which is dark brown.
Explanation:
Generally a dominant gene is the type that manifest itself from generations to generation irrespective of the presence of the recessive gene.
If there are two allele for fur colors (dark and light brown)
Therefore B(Dark brown) is a dominant allele,assuming with genotype BB.
while the recessive light brown (bb)
Therefore if the F1 generation is crossed the offspring are
Bb,Bb,Bb,Bb. These are hetero zygote dominants
Therefore the phenotype is dark brown.
In Complete dominance, the dominant allele masks the expression of the recessive allele. Heter0zyg0us individuals, carrying both alleles, only express the dominant phenotype. The fur color of a Bb mouse is dark brown.
-------------------------------------------
Available data:
A diallic gene codes for fur colorB allele is dominant and codes for dark brownb allele is recessive and codes for light brownB allele is completely dominant over the b alleleThe hint to answer this question is that The B allele causes dark brown fur and is completely dominant over the b allele. This sentence suggest that complete dominance is going on.
Complete dominance
When the dominant allele completely masks the recessive allele, we talk about complete dominance. This is the case of individuals that are heter0zyg0us for a particular gene and express the dominant phenotype. The dominant allele is hiding the expression of the recessive allele. Many genes show complete dominance.
The mouse with the heter0zyg0us genotype Bb is carrying both alleles. However, the dominant allele B hides the expression of the recessive allele b.
This mouse expresses the dominant phenotyope dark brown.
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Related link: https://brainly.com/question/20399807?referrer=searchResults
help asap giving branlist plsss helppp
Answer:
except option 2 all of them are applied
Explanation:
Produces proteins
What produces protein
Answer:
There are two organelles that produce proteins
The endoplasmic reticulum The ribosomes.Explanation:
Answer:
ribosomes
Explanation:
D
In the cytoskeleton these are the thickest of the three components, typically in cell maintenance of cell shape, chromosome movement and organelle movements.
Answer:
The correct answer is - Microtubules
Explanation:
The cytoskeleton is a complex web of fibers present and find throughout the cytoplasm
It helps in organizing the shape size, structures and activities of the cell, anchoring many organelles . It is made up of of 3 types of molecular components: Microtubules , Microfilaments , and Intermediate filaments.
Microtubules : it is the thickest of of all the 3 components of the cytoskeleton as it is made up of tubulin. Maintenance of cell shape, organelle movements, chromosome movements in cell division, cell motility are major role of microtubules.
Thus, the correct answer is - Microtubules
All of the following would be visible on a karyotype except
aneuploidy.
polysomy.
trisomy.
homologous chromosomes.
Answer: I think aneuploidy id wait for someone else to confirm this
Explanation:
All of the following would be visible on a karyotype except is aneuploidy
How to identify karyotype?The normal karyotype of the species is described as 46, may XX or XY, in which the first number of chromosomes is followed by a comma indicating the chromosomes. Thus, 46, XX corresponds to the karyotype of a woman; and 46, XY represents a male karyotype.
Aneuploidy is the presence of an abnormal number of chromosomes in a cell so this is the exception.
See more about genes at brainly.com/question/8832859
Match each of the following descriptions with the correct term:
a. Located on presynaptic membrane
b. Space between two neurons
c. Contains neurotransmitters
d. Located on postsynaptic membrane
e. Bulbous ending of axon
f. Chemical messenger
1. synaptic cleft
2. neurotransmitter
3. synaptic vesicle
4. receptor
5.axon terminal
6. calcium channel
Answer
a-6
b-1
c-3
d-4
e=5
f-2
Explanation:
The sequence shows synaptic transmission across
The arrival of action potential at the presynaptic neuron,prompted the influx of calcium ions on the presynaptic membrane to the axoplasm.
This leads to the fusion of the synaptic vessels with the post synaptic membrane,These empty their contents of neurotransmitters into the synaptic cleft.
The neurotransmitter e.g acetycholine crosses the cleft to bind with the receptors on the postsynaptic membrane,
The leads to the opening of ligand gated sodium channels which leads to the transmission of the action potential as Post Synaptic Potentials.
This is transmitted along the axon of the postsynaptic neuron,as post synaptic potential which can either be excitatory or inhibitory
g The Electron Transport Complex (ETC) consists of four proteins. How many of these proteins directly contribute to the proton gradient by moving protons across the membrane?
Answer:
Three proteins directly contribute to the proton gradient by moving protons across the membrane
Explanation:
The Electron transport chain is a group of proteins and molecules incrusted in the internal mitochondrial membrane and organized into four complexes, I, II, III, and IV. These complexes contain the electron transporters and the enzymes necessary to catalyze the electron transference from one complex to the other. Complex I contains the flavine mononucleotide -FMN- that receives electrons from the NADH. The coenzyme Q, located in the lipidic interior of the membrane, conducts electrons from complex I and II to complex III. The complex III contains cytochrome b, from where electrons go to cytochrome c, which is a peripheric membrane protein. Electrons travel from cytochrome c to cytochromes a and a3, located in the complex IV. Finally, they go back to the matrix, where they combine to H+ ions and oxygen, to form the water molecule. As electrons are transported through the chain, protons are bombed through three proteinic complexes from the matrix to the intermembrane space. These are complexes I, III and IV.
2.
When there is more water outside a cell than inside a cell, water will
O move into the cell causing it to shrink
O move into the cell causing it to expand
move out of the cell causing it to shrink
move out of the cell causing it to expand
Answer:
I'm pretty sure it is: move into the cell causing it to expand
Explanation:
22. Sickle cell disease is... (1 point)
A)autosomal dominant
B)dominant
C)sex-linked recessive
D) autosomal recessive
Answer:
D. autosomal recessive
Explanation:
Sickle cell is a hereditary disease caused by a mutation in one of the genes that encode the protein hemoglobin. It is inherited in an autosomal recessive pattern, meaning that both copies of the gene have mutations. The mutation causes the red blood cells to have a sickle shape.
Hope this helps.
Mendel crossed two plants that were heterozygous for the trait of flower color. Which genotypes could he have used to represent the cross?
PP ´ PP
Pp ´ Pp
pp ´ pp
Pp ´ PP
heterozygous means it is not the same gene expression
so both are
Pp'Pp
the second one
The genotypes that he could have used to represent the cross between two heterozygous individuals is: Pp ´ Pp
WHAT IS HETEROZYGOUS CROSS:Heterozygous cross is a cross between two individuals in which the genotype of both contains different alleles of a gene. According to this question, Mendel crossed two plants that were heterozygous for the trait of flower color. The alleles of flower color are P (purple) and p (white). This means that a heterozygous genotype will be Pp.Therefore, the genotypes that he could have used to represent the cross between two heterozygous individuals is: Pp ´ Pp
Learn more about heterozygous at: https://brainly.com/question/13050360