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A-Level Biology Test sobre Cellular control , creado por b187083 el 17/02/2016.

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Cellular control

Pregunta 1 de 11

1

What do genes code for?

Selecciona una de las siguientes respuestas posibles:

  • Polypeptides

  • Sugars

  • Hormones

Explicación

Pregunta 2 de 11

1

The genetic code is a duplet, degenerate code

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 3 de 11

1

Rellena los espacios en blanco para completar el texto.

A gene to be unwinds and unzips. The length of DNA that makes up the gene dips into the . bonds between bases break. RNA nucleotides bind to their exposed complementary bases. This is catalysed by . The two extra are released which releases energy for bonding adjacent nucleotides. The mRNA is complementary to the nucleotide base sequence on the strand of the DNA. Therefore it is a of the base sequence on the strand of the length of DNA. The mRNA is released from the DNA and passes through a to a .

Explicación

Pregunta 4 de 11

1

How does cyclic AMP activate proteins?

Selecciona una de las siguientes respuestas posibles:

  • By removing an amino acid

  • By adding an enzyme

  • By altering their three-dimensional structure

Explicación

Pregunta 5 de 11

1

Mutations cause changes to the sequence of amino acids in DNA molecules

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 6 de 11

1

When lactose is from the growth medium:
The regulator gene is expressed and the protein is synthesised. It has two binding sites, on the binds to and one that binds to the operator . The repressor binds to the operator region. In doing so it covers part of the region, where RNA normally attaches. RNA polymerase cannot bind to the promoter region so the genes cannot be transcribed into . Without mRNA these genes cannot be and the enzymes cannot be synthesised.

Arrastra y suelta para completar el texto.

    absent
    repressor
    lactose
    region
    protein
    promoter
    polymerase
    structural
    mRNA
    translated

Explicación

Pregunta 7 de 11

1

Genes that control development of body plans are similar in plants, animals and fungi

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 8 de 11

1

Which of these statements are true about apoptosis?

Selecciona una o más de las siguientes respuestas posibles:

  • It can act as a mechanism to change body plans

  • It is programmed cell death

  • It is the same as cell necrosis

  • It is controlled by cell signals originating only from inside the cells

  • Lack of apoptosis during development may cause syndactyly

Explicación

Pregunta 9 de 11

1

How many stages are there in meiosis?

Selecciona una de las siguientes respuestas posibles:

  • 4

  • 8

  • 19

Explicación

Pregunta 10 de 11

1

Selecciona la opción correcta de los menús desplegables para completar el texto.

An allele is a version of a ( gene, chromosome, chromatid ). A gene is a length of DNA that codes for one or more ( polypeptides, carbohydrates, cell membranes ).
The locus is the ( position, direction, completion ) of a gene on a chromosome.
( Crossing, Keeling, Swapping ) over is when lengths of DNA are swapped from one chromatid to another.

Explicación

Pregunta 11 de 11

1

The genotype refers to the characteristics that are expressed in the organism. The phenotype is the genetic makeup of an organism.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

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