Men have XY (or YX) chromosomes and women have XX chromosomes. X-linked recessive genetic diseases (such as juvenile retinoschisis) occur when there is a defective X chromosome that occurs without a paired X chromosome that is not defective. Represent a defective X chromosome with lowercase x, so a child with the xY or Yx pair of chromosomes will have the disease and a child with XX or XY or YX or xX or Xx will not have the disease. Each parent contributes one of the chromosomes to the child. Complete parts a through d below. a. If a father has the defective x chromosome and the mother has good XX chromosomes, what is the probability that a son will inherit the disease? 0.333
Answers
Answer:
The probability that a son will inherit the disease is zero.
The human males are XY and females are XX. In addition, fathers pass their Y chromosome to their sons and X chromosome to their daughters. In contrast, mother pass one X to chromosome to son and another X chromosome to daughters.
In the given scenario, father is xY and mother is XX. Thus, father will pass x to daughters to Y to sons. The mother pass one X chromosome to son as well as daughters.
Thus, the genotype of the sons will be XY and that of daughters will be Xx. Hence, all the daughters will be carrier and all the sons will be unaffected.
The same is explained in the Punnette square in the figure below.
Final answer:
The probability that a son will inherit an X-linked recessive disease when the father has a defective x chromosome and the mother has normal XX chromosomes is 0%, as sons will inherit a normal X from the mother and a Y chromosome (not carrying the defective gene) from the father.
Explanation:
If a father has the defective x chromosome and the mother has normal XX chromosomes, the probability that a son will inherit the disease is 50%. This is because sons inherit their Y chromosome from their father and their X chromosome from their mother.
Since the father's X chromosome is defective (x), and he can only pass Y to his sons, all his sons will be Yx - the presence of the Y chromosome makes them male, but they do not receive the defective (diseased) x chromosome from the father. Instead, they receive a normal X chromosome from their mother making them XY, which means they will not have the disease. Here is the scenario:
Father: xY (carrier of the defective allele but not affected because males are hemizygous for the X chromosome)
Mother: XX (no defective allele)
Their children's possible genotypes could be:
Daughters: xX (carriers of the disease) or XX (not carriers)
Sons: XY (not affected and not carriers)
Therefore, a son cannot inherit the X-linked recessive disease in this case since he receives the Y chromosome from his father and a normal X from his mother.
Related Questions
What type of cells line the ventricles of the brain?
Answers
Answer:
Ependymal cells called Ependymocytes
Explanation:
How does the myelin sheath help the neuron?
Answers
Answer:
Myelin sheath increases the speed of electrical impulse along the nerve cells.
Explanation:
Myelin sheath is an insulting layer of proteins and fatty acids that are present around the nerves of brain and spinal cord.
Myelin sheath increases the speed of conduction of nerve impulse from one nerve cell to another cell. Myelin sheath is formed by the concentric wrapping of schwann cells around the axon. This sheath decreases axonal membrane capacitance and increases the conduction of nerve impulse.
24. What is/are the major potential energy product(s) formed in the Krebs Cycle (not the same as end-products formed a the end of cellular respiration)?
a. NADH/FADH2
c. Carbon dioxide
b. Adenosine Tri-phosphate
d. Glucose
Answers
Answer: a. NADH/FADH2
Explanation:
Complete oxidative degradation of glucose can be compartmentalized into four main biochemical steps: glycolysis, the formation of acetyl-CoA, the Krebs (citric acid or tricarboxylic acid cycle) and the electron transport chain where oxidative phosphorylation is performed. During respiration, an organic compound (usually sugar) is completely oxidized to form CO2 and H20. The Krebs cycle is the set of reactions leading to complete oxidation of glucose. It occurs in the mitochondria of eukaryotes and the cytoplasm of prokaryotes. Per each degraded glucose molecule, resulting in the final of the Krebs cycle:
• 6 molecules of NADH.
• 2 molecules of FADH2
• 2 molecules of ATP
• 4 molecules of CO2
Which gives our answer What is/are the major potential energy product(s) formed in the Krebs Cycle? a. NADH/FADH2 because 8 molecules of them in total are made.
Binding Ca2+ to the troponin complex causes ____________ to move
a. troponin
b. actin
c. the myosin binding site
d. tropomyosin
Answers
Answer:
Tropomyosin
Explanation:
The calcium binding to troponin and induces the muscle contraction. The active binding site gets exposed due to the calcium binding.
The calcium ions then attaches with troponin molecule. This changes the shape of troponin and removes the tropomyosin protein from the binding site. No ATP is available during this process.
Thus, the correct answer is option (d).
Answer:
d. tropomyosin
Explanation:
Binding Ca2+ to the troponin complex causes the tropomyosin to move.
Tropomyosin is a protein that helps muscle contraction.
Describe the parts of a neuron including the cell body, dendrites, axons, and terminals.
Answers
Answer:
A neuron has a cell body, an axon and dendrites. Apart from these structures, the white myelin sheath covers the axons. The gaps where myelin sheath is absent are called nodes of Ranvier. Axon terminals are the extreme ends of the axon from where nerve impulse is carried to the dendrites of the post synaptic neuron.
Explanation:
A neuron has a cell body, an axon, and dendrites.
Cell body: It is the metabolic center of the neuron and does not take part in the conduction of nerve impulse.
Axon and dendrites: These are the extensions arising from the cell body. Dendrites are smaller and more in number while axon is a single large extension.
The function of the axon is to carry the nerve impulse from the cell body to the axon terminals. Dendrites receive the nerve impulse from the axon terminal and pass it to the cell body. The ends of axons are called axon terminals. They synapse with dendrites of postsynaptic neurons.
The myelin sheath is the fatty layer present on long axons and serves to accelerate the rate of conduction of nerve impulse. The nodes of Ranvier are the gaps where the myelin sheath is not present.
Suppose you were interested in the effect of breastfeeding versus formula feeding on the composition of gut flora in newborns. As part of your experiment, stool samples from healthy babies in the study get plated on various agar media. You notice that greater numbers of colonies are recovered when samples are plated on blood agar compared to Luria Bertani (LB) agar. After some diligent subculturing, you isolate several bacterial species capable of slow growth on the blood but not on the LB agar. You correctly surmise that these organisms
Choose one:
A. are opportunistic blood pathogens.
B. should be classified as beta-hemolytic.
C. have extensive and complex nutritional requirements not met by LB agar.
D. grow because the blood agar suppresses the growth of faster-growing bacteria.
E. are Gram-positive and, thus, inhibited by the ingredients in LB agar.
Answers
Answer:
Option (C).
Explanation:
Luria Bertani is a rich nutritional medium generally used for the growth of bacteria. This media was created by Giuseppe Bertani.
Bacteria shows slow growth on blood but can grow grow easily in LB agar because they have complex and extensive requirement that cannot be met by LB agar. Blood agar is more enriched media and can grow the bacteria that are dependent upon the host organism.
Thus, the correct answer is option (C).
Final answer:
The bacterial colonies are able to grow on blood agar and not LB agar because the organisms have extensive and complex nutritional requirements. Blood agar is a rich medium compared to LB agar, which accounts for their difference in growth pattern.
Explanation:
If you notice that bacterial colonies grow on blood agar but not on Luria Bertani (LB) agar, it suggests that these organisms have complex nutritional requirements that are not met by LB agar. Blood agar is a rich medium that provides many nutrients, which may explain the growth of organisms that are not growing on the simpler LB agar formulation. The correct answer to the experiment question is C: The organisms 'have extensive and complex nutritional requirements not met by LB agar.'
This does not necessarily mean the bacteria are opportunistic blood pathogens, beta-hemolytic, or that their growth is due to suppression of other bacteria. Additionally, while isolation on blood agar may commonly be associated with Gram-positive bacteria, growth on blood agar alone doesn't confirm that the bacteria are Gram-positive; this would require a Gram stain test. Therefore, option E is not the correct answer without further evidence.
Selective media are designed to suppress the growth of unwanted microorganisms and support the growth of the organism of interest, while differential media allow one to distinguish between different bacteria based on observable reactions occurring in the media, such as changes in color or clarity around colonies in the presence of specific reactions like hemolysis.
Copper in soil is usually toxic to plants, but some plants that grow near copper mines evolve copper tolerance. When copper-tolerant plants are grown in copper-free soil, they are outcompeted by the non-tolerant genotype. Which of the following principles does this scenario exemplify?
a.
The evolution of tolerance to copper resulted in a dependence on copper
b.
Evolution always maximizes the improvement or progress of a species
c.
Evolutionary changes can be advantageous under some environmental conditions but disadvantageous under others
d.
Resistant phenotypes always out-compete non-resistant phenotypes
Answers
Answer:
C. Evolutionary changes can be advantageous under some environmental conditions but disadvantageous under others
Explanation:
Evolution means to change something to survive, but that is under specific context. If we change the context, maybe that evolution is not advantegerous on the new scenario or context.
In this case, the plant evolve to survive copper in soli. If the soil has no more copper, that evolution is no longer needed.
Explain the significance of retinal changes in a patient with high blood pressure.
Answers
Answer:
Explanation:
The retina is layer of tissues that surrounds the surface of the back of the eyeball. It consists of several layers that consists of photoreceptors which detects the color and intensity of light. The retina is affected by the blood pressure levels.
When the blood pressure becomes high the retina blood vessel may become thick. This may cause the blood vessels to become narrow, this restricts the flow of blood reaching the retina.
The high blood pressure may cause damage to the retinal blood vessels, as it restricts the function of retina. The high blood pressure inside the optic nerve may cause the problem of vision. This situation is called as hypersentive retinopathy.
Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle?
A) gamma aminobutyric acid
B) acetylcholine
C) cholinesterase
D) norepinephrine
Answers
Answer:
B) acetylcholine
Explanation:
Acetylcholine is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle.
Which of the following is known to promote fat storage in adipocytes? a. Glucagonb. Lipoprotein lipasec. Cellulite synthetased. Lipoprotein synthetase e. Adipose lipase
Answers
Answer:
Lipoprotein lipasec- b.
The correct option that promotes fat storage in adipocytes is Lipoprotein lipase. Lipoprotein lipase is an enzyme found on the surface of adipocytes that promotes the uptake of triglycerides from circulating lipoproteins, such as chylomicrons and very low-density lipoproteins (VLDL), into adipose tissue for storage. This process increases the amount of body fat, contributing to fat storage in adipocytes.
Explanation:The correct option that promotes fat storage in adipocytes is Lipoprotein lipase.
Lipoprotein lipase is an enzyme found on the surface of adipocytes that promotes the uptake of triglycerides from circulating lipoproteins, such as chylomicrons and very low-density lipoproteins (VLDL), into adipose tissue for storage.
This process increases the amount of body fat, contributing to fat storage in adipocytes.
Learn more about fat storage in adipocytes here:https://brainly.com/question/33301753
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Why is it important not to misuse or overuse antibiotics?
A- Antibiotics will begin to rupture healthy cells.
B- Viral infections will become more prominent.
C- Bacteria will evolve, leading to the development of resistant bacteria
D- Normal flora will become pathogens.
Answers
Answer:
C- Bacteria will evolve, leading to the development of resistant bacteria
Explanation:
It is important not to misuse or overuse antibiotics because bacteria will evolve, leading to the development of resistant bacteria.
Answer:
Option C) Bacteria will evolve, leading to the development of resistant bacteria.
Explanation:
I took the test
Which of the meninges is a delicate connective tissue membrane that clings tightly to the brain like cellophane wrap following its every convolution?
Answers
Answer:
Pia mater
Explanation:
Three meninges cover the brain and spinal cord. Pia mater refers to the deepest meninx of the brain. It is a thin delicate layer of connective tissue. It is a transparent connective tissue layer like that of cellophane. Being a transparent and thin tissue layer, it looks like a cellophane wrap adhered to the surface of the brain.
The delicate connective tissue membrane that clings tightly to the brain and follows its convolutions is the pia mater, which is the innermost layer of the meninges.
The meninges are a series of protective membranes that cover the brain and spinal cord. Among the layers of the meninges, the innermost layer that clings tightly to the brain and follows its every convolution is called the pia mater.
This delicate connective tissue membrane is directly adjacent to the surface of the brain, fitting into the grooves and indentations of the cerebral cortex. The pia mater ensures that the brain's surface is well-protected, adapting to its intricate structures.
The other two layers of the meninges include the dura mater, which is the tough, fibrous, outermost layer, and the arachnoid mater, which is situated between the dura and pia mater and resembles a spider web.