BIO 101 Exam 3 Salihu WVU |98 Q’s and A’s
chromatin - -material chromosomes are made of; consists of RNA, DNA, and protein
-sister chromatids - -replicated chromosomes that are identical
-homologues - -maternal and paternal copies of a chromosome
-centromere - -region of contact after replication located near the middle of two strands
-spindle fibers - -fibers that extend from one side of the cell to the other that pull the sister
chromatids in anaphase of mitosis
-cytokinesis - -stage following mitosis and meiosis I and II; where cytoplasm and
organelles duplicate and divide; cytoplasmic division; happens twice in meiosis and once in
mitosis
-cleavage furrow - -indentation of the cell's surface that begins the progression of cleavage
-semi-conservative process - -during replication half conserved from the original DNA,
half is new
-DNA polymerase - -critical for process of DNA replication; adds new DNA nucleotides to
the end of primer as it builds a strand complementary to the template strand
-DNA replication in eukaryotes - -happens in nucleus
-DNA repair and proof read enzyme - -correct mistakes during DNA replication
-mutation - -A change in the nucleotide sequence of DNA
-causes of mutations - -1. Radiation
2. Chemical
3. Spontaneous
-how DNA damage happens - -1. mistakes during DNA replication
2. modify nucleotide bases, phosphate backbone broken
-hereditary mutations - -mutation occurs during fertilization/in sperm and egg
-acquired mutation - -mutation that happens in somatic cells and is caused by
environmental factors
-natural protection against mutation - -1. DNA proofreading
2. DNA repair
, 3. checking RNAs as they are made
4. eliminating malformed proteins
5. genetic code
-base substitution - -type of mutation that is sometimes called silent mutations, one
nucleotide is switched; frame not altered
-base insertion - -type of mutation; more harmful; alter reading frame by inserting a
nucleotide
-base deletion - -type of mutation where a nucleotide is deleted from sequense; more
disasterous bc frame is altered
-silent mutation - -type of mutation that doesn't alter phenotype
-mutagens - -environmental factors tht cause mutations
-one-gene, one-protein hypothesis - -one chromosome has a gene that codes for one
protein
-tumor suppressor gene - -when normal is a growth inhibiting protein and cell division is
under control; when mutated is defective and nonfunctioning and cell division is not under
control; act like brakes
-proto-oncogene - -code for proteins that help to regulate cell growth and differentiation;
when mutated increases cell division/cancer; like accelerator
-oncogene - -mutated proto-oncogene
-relationship between proto-oncogene and tumor suppressor gene - -like brake and
accelerator, need both to maintain speed; when these two are balanced you have regular
cell division
-telomere - -protective cap of chromosomes; non-coding, highly repetitive section of DNA
at the tip of euk chromosomes that shorten w every cell division; if too short then cell
division can cause the loss of functional DNA and causes cell death
-telomerase - -prevents telomere shortening; less in cancer cells
-daughter cells in mitosis - -2 identical diploid cells; have the same number of
chromosomes as parent cell
-reasons for mitosis - -1. asexual reproduction
2. growth and repair of tissue
3. injury healing
chromatin - -material chromosomes are made of; consists of RNA, DNA, and protein
-sister chromatids - -replicated chromosomes that are identical
-homologues - -maternal and paternal copies of a chromosome
-centromere - -region of contact after replication located near the middle of two strands
-spindle fibers - -fibers that extend from one side of the cell to the other that pull the sister
chromatids in anaphase of mitosis
-cytokinesis - -stage following mitosis and meiosis I and II; where cytoplasm and
organelles duplicate and divide; cytoplasmic division; happens twice in meiosis and once in
mitosis
-cleavage furrow - -indentation of the cell's surface that begins the progression of cleavage
-semi-conservative process - -during replication half conserved from the original DNA,
half is new
-DNA polymerase - -critical for process of DNA replication; adds new DNA nucleotides to
the end of primer as it builds a strand complementary to the template strand
-DNA replication in eukaryotes - -happens in nucleus
-DNA repair and proof read enzyme - -correct mistakes during DNA replication
-mutation - -A change in the nucleotide sequence of DNA
-causes of mutations - -1. Radiation
2. Chemical
3. Spontaneous
-how DNA damage happens - -1. mistakes during DNA replication
2. modify nucleotide bases, phosphate backbone broken
-hereditary mutations - -mutation occurs during fertilization/in sperm and egg
-acquired mutation - -mutation that happens in somatic cells and is caused by
environmental factors
-natural protection against mutation - -1. DNA proofreading
2. DNA repair
, 3. checking RNAs as they are made
4. eliminating malformed proteins
5. genetic code
-base substitution - -type of mutation that is sometimes called silent mutations, one
nucleotide is switched; frame not altered
-base insertion - -type of mutation; more harmful; alter reading frame by inserting a
nucleotide
-base deletion - -type of mutation where a nucleotide is deleted from sequense; more
disasterous bc frame is altered
-silent mutation - -type of mutation that doesn't alter phenotype
-mutagens - -environmental factors tht cause mutations
-one-gene, one-protein hypothesis - -one chromosome has a gene that codes for one
protein
-tumor suppressor gene - -when normal is a growth inhibiting protein and cell division is
under control; when mutated is defective and nonfunctioning and cell division is not under
control; act like brakes
-proto-oncogene - -code for proteins that help to regulate cell growth and differentiation;
when mutated increases cell division/cancer; like accelerator
-oncogene - -mutated proto-oncogene
-relationship between proto-oncogene and tumor suppressor gene - -like brake and
accelerator, need both to maintain speed; when these two are balanced you have regular
cell division
-telomere - -protective cap of chromosomes; non-coding, highly repetitive section of DNA
at the tip of euk chromosomes that shorten w every cell division; if too short then cell
division can cause the loss of functional DNA and causes cell death
-telomerase - -prevents telomere shortening; less in cancer cells
-daughter cells in mitosis - -2 identical diploid cells; have the same number of
chromosomes as parent cell
-reasons for mitosis - -1. asexual reproduction
2. growth and repair of tissue
3. injury healing
