#Question id: 5664
#Unit 5. Developmental Biology
Following statements are regarding to gamete fusion and the prevention of polyspermy in mammals.
A. In mammals, it is not the tip of the sperm head that makes contact with the egg but the side of the sperm head.
B. The junction between the inner acrosomal membrane and the sperm cell membrane is called the acrosomal region, and this is where membrane fusion between sperm and egg begins.
C. Sperm-egg fusion appears to involve several proteins, two of which are Izumo, in the oocyte membrane, and Juno, in the acrosomal membrane.
D. These fusion proteins bind together and appear to recruit other proteins to make an adhesion and fusion complex.
Which of the following statements are correct?
#Question id: 4541
#Unit 3. Fundamental Processes
Mig1 recruits a “repressing complex” containing the Tup1 protein. This complex is recruited by many yeast DNA-binding proteins that repress transcription, including the alpha2 protein involved in controlling the mating-type specific. Tup1 also has counterparts in mammalian cells, choose correct mechanisms have been proposed to explain the repressing effect of Tup1.
I-Tup1 acts on nucleosomes either through recruiting histone deacetylases and/or by positioning a nucleosome at or near the transcription start site.
II-Tup1 interacts directly with the transcriptional machinery at the promoter and inhibits initiation.
#Question id: 23681
#Unit 13. Methods in Biology
#Question id: 7551
#General Aptitude
#Question id: 7258
#Unit 5. Developmental Biology
A four-cell embryo normally develops into a blastocyst
consisting of trophectoderm (TE) cells on the outside and inner cell mass (ICM)
cells inside. The transplantation experiments were done with mouse embryos.
A. If a labeled cell is placed on the outside of a very early
embryo, it is likely to form extraembryonic tissues.
B. If a labeled cell is placed on the inside of a very early embryo, it is likely to form embryonic tissues.
According to above observations which of the following statement is true?