Imagine that you have the dna sequences from the intron of a gene in three species called a, b, and
c. species a and b are most closely related, while c is more distantly related. the sequences of a and b differ by 18 base pairs, a and c differ by 26 base pairs, and b and c differ by 28 base pairs. fossils show that species a and b diverged about 1.2 mya, but there is no fossil evidence as to when the most recent common ancestor of all three species lived. use the genetic data to estimate that date. what assumptions are you making to get this estimate?
By assuming a consistent rate of genetic change, this analysis approximates that the most recent common ancestor of all three species lived approximately 1.87 million years ago.
Explanation:Estimating the timing of species divergence using genetic data involves some assumptions. First, we assume a constant molecular clock, meaning that genetic changes accumulate at a consistent rate over time. Second, we assume that differences in DNA sequences are reflective of the time since species diverged.
Given the divergence of species A and B is known to be 1.2 million years ago (mya) and this corresponds to a difference of 18 base pairs, it suggests that the mutation rate is 15 base pairs per million years. If we apply this rate to other pairings, the divergence of species A and C, which have a difference of 26 base pairs, would be approximately 1.73 mya, and B and C, which differ by 28 base pairs, diverged approximately 1.87 mya.
The most recent common ancestor of all three species would be the most distant divergence, which is between B and C at approximately 1.87 mya.
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Brass gets discoloured in air because of the presence of which of the following gases in air?
A. Oxygen
B. Hydrogen sulphide
C. Carbon dioxide
D. Nitrogen
After fertilization, the ovule develops into a seed. can you match the parts of the ovule with the corresponding parts of the seed? drag the terms on the left to the appropriate blanks on the right to complete the sentences. resethelp
Members of the Protista kingdom contain multi-celled organisms such as kelp and single-celled organisms such as .
Answer:
The correct answer will be Paramecium.
Explanation:
Protista is a heterogeneous group of simple eukaryotic organisms which did not arise from a single ancestral protist.
The members of protist are polyphyletic, which means they are not closely related to each other and do not share many common characters. They vary greatly in organization from single-celled to synctial to multi-cellular organisms.
The most common single-celled protista is Paramecium.
Paramecium are unicellular protist found in freshwater habitats, shaped like a sole of a shoe with short hairy structures on its body called cillia. Cillia helps in locomotion and dragging the food to its oral cavity.
Thus, Paramecium is the correct answer.
Many of the proteins in the human body are enzymes that catalyze chemical reactions. What is the relationship between enzymes and activation energy?
Answer:
When an enzyme catalyzes a reaction, it does not affect the activation energy of the reaction.
Explanation:
Organs, such as the stomach and the small and large intestines, are lined with smooth muscle tissue. These organs, due to the muscular contractions of their walls, involuntarily A) grind food into smaller pieces. B) move food through the digestive tract. C) add liquids to food to make it a slurry. D) supply digestive enzymes that aid in digestion.
the answer is b move food through the digestive tract
He association of two or more polypeptides in a multimeric protein is known as the:
How can karyotype analysis detect genetic disorders lab 12-2 answers?
Karyotype enable viewing of the physical attributes of chromosomes. When compared to the karyotype of a normal individual, any abnormalities in chromosomes can be identified by either noticing an abnormal number of chromosomes or pairing (aneuploidy), or regional changes within chromosomes such as shorter or longer than normal chromosomes due to translocations.
Describe the function of the structure pictured below.
a. Spore production
b. Food absorption
c. Water uptake
d. Enzyme release
Spores are the reproducing body of an organism. Option A is correct. The function of the structure in the given picture is spore production.
Spores:
Spores are the reproducing body. They are found in the lower organisms such as Fungi, algae, and lower plants.
Spores can be Haploid or Diploid depending upon the life cycle.
In the picture, The lower blob-like structure is a stalk that produces spores and a small ball-like structure is spores.
Food is absorbed inside the stomach. Enzymes are released from the cells.Therefore, the function of the structure in the given picture is spore production.
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The nurse is assessing a patient who is malnourished and has a history of poor nutrition. the patient reports difficulty seeing at night. this patient is likely to be deficient in which fat-soluble vitamin?
In the Winter, temperatures are cold, whether it's a windy day or not. The daily weather condition expressed here is the _____.
a. Temperature
b.Winter
c. Wind
(30 POINTS)
temature is the answer
A heterozygous individual has a _____ for a trait being studied.
a. haploid condition, in genetic terms
b. pair of identical alleles
c. pair of nonidentical alleles
any rock formed from molten material from inside the earth is 1-igneous, 2-metamorphic 3- sedimentary 4- weathered
Consider the cladogram. mc014-1.jpg Which group of organisms has the derived characteristics of true tissues, bilateral symmetry, and a pseudocoelom
sponges
roundworms
annelids
chordates
The right answer is roundworms
In the scientific sense, worm refers to the primitive form of organization of the Bilaterians. The three groups of animals (roundworms, flatworms and ringed worms) have a fundamental bilateral symmetry. Their appearance, probably at the very beginning of the Cambrian (primary era), marks an important stage in the evolution of living beings. In spite of their apparent simplicity, they inaugurate a new type of anatomical organization which will then be taken over by all other animal species. The different tissues or specialized organs, come from one of the three embryonic leaves (endoderm, mesoderm and ectoderm) inaugurated by these verses.
Why are all of the organs in the alimentary canal important in digesting food? As food passes through each organ, different hormones are produce to help break it down so that our body can easily absorb nutrients. Each organ has the same role in digesting food but is necessary in order to efficiently break food. The human body needs a long time to digest food in order to be able to absorb nutrients.
Answer:
the first one
Explanation:
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Gregor Mendel determined that some tall pea plants carried the dominant gene TT, while dwarf pea plants carried the recessive gene tt.
Part A: Draw a Punnett square showing the possible genotypes for the first generation of offspring.
Part B: What percent of plants in the first generation will be dwarf pea plants?
Energy in most ecosystems must flow through autotrophs because ______.
Energy in most ecosystems must flow through autotrophs because only autotrophs can convert solar energy in chemical energy.
Explanation:
This suggests that these are organisms which are entirely based on the Greek name self-producers that can produce complex organic materials by fixing together simple building blocks in their local situation. E.g plants on land. Photosynthesis in plants transforms solar energy into chemical energy using electrons and protons from water. The method of photosynthesis in plants involves a series of steps and reactions that use solar energy, water, and carbon dioxide to produce organic aggregates and oxygen.
Can the genotype for a gray-bodied fly be determined? why or why not? describe all of the possible genotypes for a fly with that phenotype. *
What factors have affected (and will continue to affect) the growth of health psychology?
Inherited character traits and genetic abnormalities are examples of biological factors. Style of living, personality traits, and stress levels are all examples of psychological factors.
What is health psychology?The study of psychological and behavioral processes in health, illness, and healthcare is known as health psychology.
The discipline seeks to comprehend how psychological, behavioral, and cultural factors influence physical health and illness.
Being in a good mental state can help you stay healthy and prevent serious health problems.
According to one study, positive psychological well-being can lower the risk of heart attacks and strokes. Poor mental health, on the other hand, can lead to poor physical health or harmful behaviors.
The study of how biological, social, and psychological factors influence health and illness is known as health psychology.
Psychological science is used by health psychologists to promote health, prevent illness, and improve health care systems.
Thus, these are the factors that affect the growth of health psychology.
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A plant that has flower parts that occur in multiples of four or five is usually a
Widow's peak, a pointed hairline on the forehead, is a genetic trait caused by a dominant allele. it can be traced back through a family's history using pedigree analysis. the pedigree shown here is of three generations of a family. notice that some individuals (shown in gray) have a widow's peak (w = dominant allele and w = recessive allele). this pedigree supports the fact that widow's peak is due to a dominant allele, because if it were due to a recessive allele and both parents show the recessive phenotype, then ________.
Which planets have rings? Check all that apply. Jupiter Mercury Saturn Venus Uranus Neptune Earth Mars
Jupiter, Saturn, Uranus, and Neptune
Jupiter, Saturn, Uranus, and Neptune have rings. The ring system of Jupiter is thin and dark and is chiefly made up of dust. It can only be seen by using most powerful telescopes. The ring system of Saturn contains 12 rings with 2 divisions and many gaps. The rings are wide and colorful. Uranus has 13 rings which are all very faint, while Neptune has 6 rings which are also faint and thin.
The _____ sends out an electrical impulse that regulates the heartbeat.
Answer: The SA node
Answer choices are:
A. The AV node
B. The SA node
C. The purkinje fibers
D. The AV bundle
The SA node is the heart's natural pacemaker consisting of a cluster of cells located in the upper part of the wall of the right atrium. (the right upper chamber of the heart). The electrical impulses are produced and sent out from there to regulate heartbeat. This is also called the sinus code.
Protective antibodies are produced in the primary response to a microbe then in smaller amounts during secondary responses.
a. True
b. False
earth's magnetic field affects what?
Which factor differentiates between weather and climate
Answer:
the length of time over which conditions are measured
Explanation:
apex
According to the fossil record, which of these evolved after amphibians? Check all that apply. mammals sponges fish bacteria reptiles Mark this and return
According to the fossil record, mammals and reptiles are evolved after amphibians.
What are the characteristics of amphibians?Amphibians are four-limbed and ectothermic vertebrates of the class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial, fossorial, arboreal.
Amphibians have a backbone, are cold-blooded, need a moist place to live, can breathe air through their skin, externally fertilize their eggs, eat meat, and grow legs when they mature.
Amphibians are a class of cold-blooded vertebrates made up of frogs, toads, salamanders, newts, and caecilians (wormlike animals with poorly developed eyes).
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What is the expected growth mile markers for a 6-month infant?
If we traced the sensory pathways that carry sarah's thigh pain up to her brain, which cerebral lobe and which part of the cortex would be active when she feels this sensation?
Answer:
Parietal lobe and left primary somatosensory cortex
Explanation:
The parietal lobe is that area of integration where it passes much of the information from the rest of the brain regions. It is he who organizes, who allows us to feel and understand the reality around us. It is through him that we perceive the touch of someone, the feeling of the hug and the force of a blow that causes pain.
In addition to the parietal lobe, the primary sensory cortex is also responsible for receiving tactile information from the body. Thus, we can state that when we feel a physical pain, such as Sarah who is experiencing leg pain, the parietal lobe and primary sensory cortex will be active.
Birds, insects, and many reptiles excrete nitrogenous waste in the form of uric acid, which _____. is not very toxic compared to other nitrogenous wastes, but requires the loss of a lot of water with its excretion reduces water loss compared to other nitrogenous wastes, but is highly toxic is much more soluble in water than other nitrogenous wastes, but is energetically costlier than other nitrogenous wastes to synthesi reduces water loss compared to other nitrogenous wastes, but requires more metabolic energy to produce reduces energy use compared to other nitrogenous wastes, but is highly toxic to animals that produce it