What is true about the relationship of dna and chromosomes?
chromosomes manufacture the proteins that build the dna molecule.
chromosomes unwind the dna molecule so that sections can be made into genes by rna.
various nucleotide sequences of dna code for different chromosomes.
each chromosome contains a single, tightly wound dna molecule.
what is true of all body cells except sex cells?
each cell type carries chromosomes and genes that identify it as that specific type of cell. for example, skin cells have different chromosomes and genes than muscle cells.
each body cell contains the same number and kinds of chromosomes for that organism. the chromosomes contain the same number and kinds of genes for that individual.
while each cell in the body contains the same number of chromosomes, each cell type has different genes along those chromosomes.
while each cell type in the body contains the same kinds of genes, they are organized on different chromosomes depending on the cell type.
what role does mrna play in the delivery of genetic code information?
mrna reads the code from one gene on a chromosome and then delivers that message to rrna.
mrna copies the code from one segment of dna that represents one gene and then carries it out of the nucleus to a ribosome.
mrna transports a gene segment to trna where the code is read and an amino acid is made.
mrna collects the dna from all of the chromosome and duplicates it using nucleotide base pairs.
a snapping turtle has 52 chromosomes. which statement correctly compares the number of chromosomes in a body cell with that in a sex cell of a snapping turtle?
the body cell has 2n; the sex cell has 1n.
the body cell has 26; the sex cell has two.
the body cell has 1n; the sex cell has 2n.
the body cell has 24; the sex cell has 26.
which statements correctly compare mitosis and meiosis?
the result of mitosis is two identical diploid cells. the result of meiosis is four genetically different haploid cells.
mitosis brings genetic variety to a species. meiosis the body grow and heal.
mitosis involves two cycles of cell division. meiosis involves one cycle of cell division.
cells that divide by mitosis carry the genetic information for body cells. cells that divide by meiosis provide only the code for gender.
which phase of cell division includes the pinching off or cleaving of the cell into two new cells?
prophase
metaphase
anaphase
telophase
which statement describes the chromosomes by the end of telophase of mitosis?
the chromosomes have coiled and become more compact.
the chromosome pairs collect in a line across the middle of the cell.
the chromosomes separate at the centromere and begin to move apart.
the chromosomes reach opposite sides of the cell and begin to be incorporated into two new nuclei.
which phase of sex cell production results in homologous pairs of chromosomes forming?
prophase i of meiosis
anaphase ii
telophase i
telophase ii
which describes the chromosomes by the end of prophase ii of meiosis?
the chromosomes in each of two diploid cells coil and become more compact.
the chromosomes in each of two diploid cells line up in the middle of the cell.
the chromosomes of two haploid cells split apart at the centromere.
the chromosomes of two haploid cells reach opposite sides of the cell and incorporate into two new nuclei.
a frog is the best jumper in the pond due to its long legs. what is true about this frog's heritable traits?
its parents passed on genes for jumping distances through the chromosomes found in their gametes.
its parents taught it the tricks to jumping farther.
its parents passed on genes for longer legs through the chromosomes found in their gametes.
it spent more time practicing jumping greater distances.
two genes for the same trait are compared. which one is not an example of a mutation?
in the first, the series is adenine followed by two thymine; in the second, adenine is followed by two thymine.
in the first, the series is cytosine - adenine - thymine; in the second, it is cytosine - adenine - adenine.
the first has thymine where the second has a guanine.
the first has a series of three nucleotide bases; the other has a series of four.
which headline would be an example of gene therapy?
pet fish glow under ultraviolet light
farmer brown's pigs have less saturated fat
prize winning orchid is a hybrid
gene added to bone marrow improves immune system function
which sentence properly uses the word genotype?
having inherited one dominant and one recessive gene for height, the genotype of the plant was heterozygous.
each of the homologous chromosomes in the pair had the same recessive genotype.
each gamete had the same genotype on each chromosome, so the result was identical twins.
the genotype was not a mutation because mrna successfully copied the dna strand.