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- Question
Origins of genetic variation
Options- A. intragenic recombination
- B. mutation
- C. reticulation
- D. All the above
- Correct Answer
- All the above
ExplanationRandom mutations are the ultimate source of genetic variation. Mutations are likely to be rare and most mutations are neutral or deleterious, but in some instances, the new alleles can be favored by natural selection. Polyploidy is an example of chromosomal mutation.
Mutations are changes in the DNA. A single mutation can have a large effect.
1) mutation - an alteration in DNA sequence, various types
2) intragenic recombination - results in entirely new associations of genes not present in either parental genome.
Two forms of intragenic recombination:a) crossing over
b) independent assortment
3) reticulation ? acquisition of genetic material from unrelated or relatively unrelated sources (e.g., hybrid species, horizontal gene transfer). - 1. Where is glucose stored in the body?
Options- A. bones
- B. blood
- C. organs
- D. None of the above Discuss
- 2. The inherited traits of an organism are controlled by
Options- A. DNA
- B. Enzymes
- C. Nucleotides
- D. RNA Discuss
- 3. Where in the cell are chromosomes located?
Options- A. mitochondria
- B. DNA
- C. RNA
- D. Nucleus Discuss
- 4. Which statement describes decomposers?
Options- A. Decomposers are insignificant organisms in the ecosystem and can be absent in some ecosystems.
- B. Decomposers can produce their own source of energy and can sometimes act as primary producers.
- C. Decomposers are those organisms that recycle matter in the ecosystem..
- D. All the above Discuss
- 5. Which of the following is considered a modified stem?
Options- A. Tendril
- B. Taproot
- C. Petiole
- D. Tuber Discuss
- 6. Which best describes transformation in bacteria?
Options- A. Bacteria take DNA from their environment.
- B. Bacteria inject DNA into another cell.
- C. Bacteria lie dormant for many weeks.
- D. Bacteria transfer DNA with a bacteriophage. Discuss
- 7. Which of the following statements about aldosterone is NOT correct?
Options- A. Aldosterone increases sodium reabsorption by increasing the number of Na+-K+ ATPase pumps in the luminal membrane of the proximal tubule.
- B. Aldosterone is stimulated by decreased plasma sodium levels and increased plasma potassium levels.
- C. Aldosterone is produced in the adrenal cortex.
- D. Aldosterone increases the number of passive sodium channels in the luminal membrane of the distal tubule and collecting duct, thus aiding sodium reabsorption. Discuss
- 8. What does the central nervous system consists of?
Options- A. Brain
- B. Spinal cord
- C. Nerves
- D. All the above Discuss
- 9. Who discovered the monomers of nucleic acids?
Options- A. James Watson, Francis Crick, and Rosalind Franklin
- B. Friedrich Miescher
- C. Phoebus Levene
- D. Gerardus Johannes Mulder and Jöns Jacob Berxelius Discuss
- 10. Reuptake refers to the
Options- A. reabsorption of excess neurotransmitter molecules by a sending neuron
- B. release of hormones into the bloodstream
- C. movement of neurotransmitter molecules across a synaptic gap
- D. inflow of myelin through an axon membrane Discuss
Biology problems
Search Results
Correct Answer: blood
Explanation:
In human body, glucose is stored in blood stream before it is converted to glycogen. Excess glucose is stored in the form of fats. After conversion, glycogen is stored in Muscles and Liver.
Correct Answer: DNA
Explanation:
The inherited traits of an organism are controlled by DNA molecules.
The traits an organism displays are ultimately determined by the genes it inherited from its parents, in other words by its genotype. Animals have two copies of all their chromosomes, one from each parent.
Correct Answer: Nucleus
Explanation:
In all plants and animal cells chromosomes are located in the Nucleus of the cells.
The Chromosomes are thread like structures present in the nucleus of the cells which are made up of proteins and a single molecule of DNA.
Their function is to carry the characteristic features of parent cells to daughter cells.
Correct Answer: Decomposers are those organisms that recycle matter in the ecosystem..
Explanation:
Decomposers are organisms that break down dead or decaying organisms, and in doing so, they carry out the natural process of decomposition.
The statement "Decomposers are those organisms that recycle matter in the ecosystem" describes decomposers.
Correct Answer: Tuber
Explanation:
Tuber is considered as a modified stem. These type of stems carry out special functions that are important for the plant to survive. Tubers serves as a food reserve and bearing buds wherein new plants can grow.
Correct Answer: Bacteria take DNA from their environment.
Explanation:
"Bacteria take DNA from their environment" is what best describes transformation in bacteria.
Correct Answer: Aldosterone increases sodium reabsorption by increasing the number of Na+-K+ ATPase pumps in the luminal membrane of the proximal tubule.
Explanation:
Aldosterone, the main mineralocorticoid hormone, is a steroid hormone produced by the zona glomerulosa of the adrenal cortex in the adrenal gland. It is essential for sodium conservation in the kidney, salivary glands, sweat glands and colon.
Correct Answer: All the above
Explanation:
The central nervous system CNS is responsible for integrating sensory information and responding accordingly.
It consists of two main components::
1. The brain
2. The spinal cord
The brain is the center of our thoughts, the interpreter of our external environment, and the origin of control over body movement. The brain can be divided into four main lobes: temporal, parietal, occipital and frontal.
The spinal cord serves as a conduit for signals between the brain and the rest of the body.
Correct Answer: Phoebus Levene
Explanation:
Deoxyribonucleic acid (DNA) is a nucleic acid polymer composed of monomers called nucleotides. Nucleotides are composed of three components: (1) a pentose sugar; (2) a nitrogenous base; and (3) one to three phosphate groups.
Phoebus Levene, a Russian biochemist was the first to discover the nucleotide and the first to correctly identify the way nucleic acid molecules, DNA.
Correct Answer: reabsorption of excess neurotransmitter molecules by a sending neuron
Explanation:
Reuptake refers to the process in the brain of neurons to retrieve chemicals that were not received by the next neuron. Neurons are cells in the brain that have miniscule spaces between them. They communicate with each other by sending chemicals across the space to the next neuron.
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