Final- chapter 7-9

molecule that carries the gene sequence to ribosomes
messenger rna
transcription starts at a region of dna called a
promoter
if the dna coding sequence was cga-atc the mrna would be
gcu uag
in eukaryotes, what modification occurs to the mrna transcript
the non coding intron segments are removed
how many nucleotides compose one codon
3
how many different amino acids make up the genetic code for proteins
20
which of the following carries amino acids to ribosomes
trna
what specifically determines the sequence of amino acids in a polypeptide of eukaryotes
the exons
which of the rnas act as an enzyme
rrna
for eukaryotes transcription takes place in the
nucleus
translation stops when
one of the three stop codons is encountered
a gene mutation
all of these
frameshift mutations may involve
insertion of one to several base pairs
homeotic genes are in general, in control of
formation of major body parts
the tightley condensed non functional x chromosome is called and
barr body
in mitosis
the chromosome number stays the same
cells with two of each kind of chromosome are discribed by the term
diploid
animal cells divide using a contractile ring by
pinching
in mitosis if a parent cell has 12 chromosomes each daughter cell will have how many chromosomes
12
cells with two of each kind of chromosome are described by the term
diploid
animal cells divide using a contractile ring by
pinching
an accumulation of cells that divide uncontrollably is known as
neoplasms
an omcogene is
a mutated gene that results in tumors
proto oncogenes are
normal genes that promote mitosis
asexual reproduction
produces clones
sexual reproduction
results in new combinations of genetic traits
alternative or different forms of the same gene are called
alleles
which of these is a disadvantage of asexual reproduction
less genetic diversity in offspring
if meiosis did not occur in sexual reproducing organisms
the chromosome number would double each generation
a chicken somatic cell carries 78 chromosomes. a chicken sperm cell will contain how many chromosomes
39
crossing over is one of the most important events in meiosis because
it produces new combinations of alleles on chromosomes
a _____is an offspring of a cross between two individuals that breed true for different forms of a trait
hybrid
which of the following determines an observable trait
genotype
an allele is ______ if its effect masks that of a ______ allele paired with it
dominant recessive
in humans skin color is controlled by several genes. thus skin color is an _____ characteristic
epistatic
what tool do geneticists use to study the genetics of families through generations
pedigrees
males more commonly are affected by , linked recessive genetic disorders than are females because
males have only on x and thus more of a chance to be recessive
why are most x linked disorders recessive
dominant x linked disorders are almost always fatal to the male embryo
amniocentesis is
used in prenatal diagnosis to detect chromosomal mutations and genetic disorders in embryos