bio exam 3

an RNA copy of a gene is produced through the process of ___

transcription

the enzyme that catalyzes the formation of covalent bonds between adjacent okazaki fragments to complete the replication process of DNA

Ligase

The DNA protein complex that makes up the eukaryotic chromosomes is termed

chromatin

translation is the process of creating a polypeptide from an mRNA template on structures called

ribosomes during protein synthesis

the synthesis of an RNA copy of a gene is called?

transcription, which occurs in the nucleus.

DNA is ___ to produce mRNA, which is then ____ to produce proteins that determine the traits on organism expresses

transcribed then translated

The chromatin that makes up eukaryotic chromosomes is a complex of.

proteins and DNA

which of the following best describes the process of transcription

DNA → RNA

What end of a eukaryotic mRNA is modified by the addition of a cap?

5’

how is the 3’ end of eukaryotic mRNA modified?

a poly A tail is added to it

how is the 5’ end of eukaryotic mRNA modified?

a cap is added to it

what part of the gene signals the end of transcription

terminator

what process allows a single gene to encode two or more polypeptides with difference amino acid sequences?

alternative splicing

In eukaryotes, pre mRNA go through the processes of ____ modifications before it can become a mRNA

pre-mRNA are spliced, capped, and polyadenyalated prior to translation.

the genetic code is read in groups of three nucleotide bases known as?

codons

during the process of mRNA splicing what happens?

Introns are removed from the transcript; exons are joined together.

a codon in a messenger RNA molecule consists of ___ nucleotides. Each mRNA codon specifies ___ amino acids

three; one

how many nucleotide bases in one codon

3

more than one codon can specify the same amino acid. Thus, the genetic code is said to be

degenerate/redundant

which RNA molecule involved acts an intermediary between an mRNA codon and an amino acid

tRNA

the function of a tRNA is to

carry the amino acids used in translation

which macromolecules are found in ribosomes

RNA and protein

relatively small changes in DNA sequence are known as

gene mutations

the mRNA, tRNA, and ribosomal subunits are assembled

initiation

peptide bonds are formed between amino acids to syunthesize a polypeptide

elongation

a release factor binds to the A site of the ribosome

termination

how is an mRNA sequence used to produce a specific amino acid sequence?

a codon on mRNA base pairs with an anticodon on a tRNA that carries the appropriate amino acid

what does a gene mutation affect?

the seqauence of bases in a particular gene

a mutation that affects only a single base pair in the DNA is termed?

point mutation

what type of mutation changes a single amino acid in a polypeptide sequence?

missense

a mutation that converts a normal codon to a stop codon is called?

nonsense mutation

which of the following steps occurs last during cancer progression?

metastasis

the activity of an oncogene is ___ that of a normal gene

higher than

an overgrowth of cells, which can be benign or become cancerous, is known?

tumor

the scientific term for programmed cell death is?

apoptosis

series of events that take place in a cell, leading to its division

cell cycle

what are sister chromatids

identical structures formed wehn a chromosome is copied

in humans, the X and Y chromosomes are called the ___ chromosomes

sex

chromosomes that are not sex chromosomes are called?

autosomes

a diploid organism contains?

two sets of chromosomes

in a diploid organism, the members of a pair of chromosomes are called

homologs

what do the G1, S, and G2 phases collectively represent?

interphase

the cell has postponed proceeding through G1 and is considered nondividing in a phase of cell cycle called the ___ phase

G zero

in general, mitosis is quickly followed by a stage in which the two nuclei are segregated into separate daughter cells. This state is called?

cytokinesis

bivalent formation and crossing over are two key events that typically occur at the beginning of which of these?

meiosis only

Meiosis I sorting separates with of these?

Homologous chromosomes

what phase of mitosis is characterized by the reformation of the nuclear envelop and the production of two separate nuclei?

telophase

what is the phase in which the two nuclei are segregated into separate daughter cells by the division of cytoplasm

cytokinesis

homologous chromosomes are separeted from each other during

meiosis I only

the formation of bivalents and subsequent crossing over occur in what phase of meiosis

prophase I

during metaphase I of meiosis, the bivalents are organized along the metaphase plate. In particular, the sister chromatids are?

randomly aligned in a double row

the process involving two sequential cell divisions that generates four haploid cells is called?

meiosis

the idea that the two alleles of a gene separate during the formation of eggs and sperm so that every gamete receives only one allele is known as Mendel’s law of?

segregation

the set of observable characteristics or traits of a living organism

phenotype

refers to the combination of alleles

genotype

a situation where a single individual expresses two different alleles is referred to as

codominance

a genetic pattern where neither allele is completely dominant over the other

incomplete dominance