BIOM 3040 test 1 Exam Questions AND Correct Answers
dizygotic twins - ✔✔from two eggs fertilized by 2 different sperm
How is the blastocyst hatched? - ✔✔occurs prior to implantation
embryo breaks through ZP due to proteases secreted by blastocyst
monozygotic twins - ✔✔from one fertilized egg and a single spermatozoon
Spermatogenesis - ✔✔process in which spermatozoa are produced from male
primordial cells by way of mitosis and meiosis
What are 3 characteristics of crossing over? - ✔✔occurs in all sex chromosomes
not purely random
occurs at "hot spots" along the chromosome
What are primordial cells germ cells? - ✔✔The earliest recognizable precursors
of gametes
what are the 2 proteins involved in crossing over? - ✔✔cohesin
condensin
What are the 4 phases of gametogenesis? - ✔✔1. Extraembryonic origin of PGCs
and their migration to the gonads
2. An increase in the number of PGCs by mitosis
3. A reduction in chromosomal material by meiosis
, 4. Structural and functional maturation of gametes (oogenesis,
spermatogenesis)
What are the 4 stages in spermatogenesis? - ✔✔Spermatocytogenesis
spermatidogenesis
spermiogenesis
spermiation
What are the events associated with cleavage? - ✔✔initial division of zygote to
form embryo
involves rapid mitotic divisions with no growth phases
blastomeres
blastomeres are smaller with each division since there is no overall growth
blastomeres up to 8-cell stage are totipotent
What are the functions of cleavage? - ✔✔to convert unicellular zygote into
multicellular embryo
what are the functions of the zona pellucida? - ✔✔promotes maturation of
oocyte and follicle
only allows sperm of the same species access to egg
initiates acrosomal reaction
prevents any additional spermatozoa from reaching the sygote
acts as porous filter through certain substances secreted by uterine tube can
reach embryo
immunological barrier
dizygotic twins - ✔✔from two eggs fertilized by 2 different sperm
How is the blastocyst hatched? - ✔✔occurs prior to implantation
embryo breaks through ZP due to proteases secreted by blastocyst
monozygotic twins - ✔✔from one fertilized egg and a single spermatozoon
Spermatogenesis - ✔✔process in which spermatozoa are produced from male
primordial cells by way of mitosis and meiosis
What are 3 characteristics of crossing over? - ✔✔occurs in all sex chromosomes
not purely random
occurs at "hot spots" along the chromosome
What are primordial cells germ cells? - ✔✔The earliest recognizable precursors
of gametes
what are the 2 proteins involved in crossing over? - ✔✔cohesin
condensin
What are the 4 phases of gametogenesis? - ✔✔1. Extraembryonic origin of PGCs
and their migration to the gonads
2. An increase in the number of PGCs by mitosis
3. A reduction in chromosomal material by meiosis
, 4. Structural and functional maturation of gametes (oogenesis,
spermatogenesis)
What are the 4 stages in spermatogenesis? - ✔✔Spermatocytogenesis
spermatidogenesis
spermiogenesis
spermiation
What are the events associated with cleavage? - ✔✔initial division of zygote to
form embryo
involves rapid mitotic divisions with no growth phases
blastomeres
blastomeres are smaller with each division since there is no overall growth
blastomeres up to 8-cell stage are totipotent
What are the functions of cleavage? - ✔✔to convert unicellular zygote into
multicellular embryo
what are the functions of the zona pellucida? - ✔✔promotes maturation of
oocyte and follicle
only allows sperm of the same species access to egg
initiates acrosomal reaction
prevents any additional spermatozoa from reaching the sygote
acts as porous filter through certain substances secreted by uterine tube can
reach embryo
immunological barrier
