Chapter 1 And 2 Flashcards
How many chromosomes make up the human genome
46 chromosomes, 23 pairs
how many autosome make up human genome
22 autosomes, one pair of sex chromosomes
how many different chromosomes do male and females have
24 for male and 23 for female
describe basic structure of DNA
5 carbon sugar, nitrogen base, and phosphate group
has complementary two strands
function of DNA
carry chemical info that can transmit genetic info from daughter cell to next generation
what two “arms” make up a chromosome
p (short )and q (long)
what structures make up a chromosome
DNA and histone proteins
what is difference of chromatin and chromosome
chromatin: loose, uncoiled form
chromosome: tightly wound, condensed form
how to distinguish different chromosomes
by length, location of centromere and sequence content
about how many genes make up human genome
20,000-25,000
what is a gene
physical and functional unit of heredity
human body cells carry how many copies _____
diploid - 2 copies of every gene
what is exon
sequence of DNA that is expressed
what is mitosis
somatic cell division where tissue regeneration 46 chrom and 23 pairs
what state of cell cycle does the cell spend most of its life in
interphase
what cells does meiosis occur in and what is it
happens in germline cells where formation of reproductive cells with 23 chromomes occurs
what is chromosome segregation
process of distributing a copy of each chromosome to each daughter cell
what does meiosis result in
4 haploid gametes
what four structures are made up of repetitive DNA
centromere, Alu elements (insertion, disrupting, transcription), LINE elements (insertion, interrupting, and coding sequence), and telomeres
distinct feature of meiosis is
recombination
what is nondisjunction or chromosome missegregation
when homologous chromosomes fail to segregate to opposite poles
crossing over is what
exchange of genetic information from non-sister chromatids
