Questões de estudo 1 Flashcards
What molecule carries genetic instructions in cells?
a. Protein
b. DNA
c. Chromatin
d. RNA
c.
When does genetic recombination occur?
a. During meiosis
b. During mitosis
c. During trnscription
d. During translation
a.
What are the components of DNA?
a. mRNA transcripts and tRNA adaptors
b. Lipids and fatty acids
c. Nucleotides containing nitrogenous bases, phosphate groups and sugar molecules
d,. Amino acids and peptides
c.
When was DNA discovered to be the molecule of heredity?
a. 1951
b. 1944
c. 1928
d. 1869
b.
What are the two types of nitrogenous bases found in DNA?
a. Purines and pyrimidines
b. Double-ring and single-ring bases
c. Aromatic and aliphatic bases
d. Heterocuclic and acyclic bases
a.
What type of bonds hold the two strands of the DNA double helix together?
a. Ionic bonds
b. Covalent bonds
c. Hydrogen bonds
d. Van der Waals forces
c.
What principle allows DNA strands to be separated for replication?
a. Purine-pyrimidine attaction
b. Phosphodiester backbone
c. Complementary base pairing
d. Weakness of hydrogen bonds
d.
What type of sugar is found in DNA but not RNA?
a. Galactose
b. Glucose
c. 2’-deoxyribose
d. Ribose
c.
What did Rosalind Franklin determine through her X-ray diffaction images of DNA?
a. The sequence of nucleotides in DNA strands
b. How DNA replicates
c.The helical nature of DNA
d. The four nucleotide bases of DNA
c.
When does DNA exist as double helix?
a. Never, it is always single-stranded
b. During replication
c. Only when packaged as chromosomes
d. At all times in the cell
d.
What does the term ‘antiparallel’ refer to in the context of DNA structure?
a. The attraction between nucleotide bases
b. The opposite orientation of the DNA strands
c. The twisting of DNA into a helix
d. The double-stranded nature of DNA
b.
What determines the right-handed helical shape of DNA?
a. Interactions between phosphate groups
b. Hydrogen bonding between bases
c. The antiparallel orientation of the strands
d. The sequence of nucleotides
c.
What molecule was shown to be responsible for transmitting genetic information between generations according to the Hershey-Chase experiment?
a. Protein
b. RNA
c. DNA
d. Carbohydrates
c.
What is the double helical structure of DNA composed of?
a. Interwoven protein strands
b. Paired subunits called nucleotides, with each mucleotide containing one of the four nitrogenous bases: adenine, thymine, guanine, or cytosine
c. Repeating sugar-phosphate groups
d. Amino acids arranged in a coiled coil formation
b.
When was the double helical structure of DNA proposed by Watson and Crick?
a. 1944
b. 1953
c. 1901
d. 1952
b.
What principle of base pairing did the Watson-Crick DNA model propose?
a. Complementary base pairing between adenine and thymine, and guanine and cytosine
b. Three-base condons arranged in a linear sequence
c. Random base pairing between any of the four nitrogenous bases
d. One-to-one base pairing between each nitrogenous base
a.
What is the double helical stucture of DNA composed of?
a. A coiled ladder-like arangement of protein subunits
b. Amino acids arranged in parallel strands
c. Nucleotides bound together by hydrogen bonds between complementary nitrogenius bases
d. Simple sugars and phosphates in a repeating helical pattern
c.
What did Beadle and Tatum’s experiments on Neurospora crassa demonstrate?
a. Each gene controls multiple enzymes
b. Alternative splicing occurs in fungi
c. Enzymes can be decoded in different genes
d. Mutations can impact enzymatic function
c.
What principle allows for the replication of DNA during cell division?
a. Simultaneous synthesis of both new strands
b. Complementary base pairing between strands
c. Progressive shortening of the DNA molecule
d. Random assortment of nucleotides into new strands
b.
What is the gene-one enzyme hypothesis?
a. Genes only encode enzymes, not other proteins
b. Each gene encodes multiple proteins through alternative splicing
c. Alternative promotes do not exist
d. Each enzyme is encoded by a single gene
d.
When does transcription of genetic information form DNA to RNA occur?
a. When proteins need to be synthesized
b. Randomly throughout the cell cycle
c. When a cell is preparing to divide
d. During DNA replication before cell division
a.
According to the passage, how is the one gene-one enzyme hypothesis described?
a. Inexact
b. A completely accurate principle
c. A fully validated experimental finding
d. A purely theoretical concept
a.
What is the genetic material that encodes the sequence of amino acids in proteins?
a. Proteins
b. RNA
c. DNA
d. Amino acids
c.
What cellular mechanisms allow a single gene to encode multiple proteins?
a. Point mutations during transcription
b. Transposable element insertion
c. Gene duplication and divergence
d. Alternative splicing and alternative promoters
d.
