A ribbonlike structure consisting of three protein components and extending across the region of synapsed chromosomes during the prophase of meiosis, is called:
1. Phragmoplast
2. Phragmosome
3. Synaptonemal complex
4. Recombination nodule
Which statement regarding enzyme inhibition is correct?
1. Competitive inhibition occurs when a substrate competes with enzyme for binding to inhibitor protein
2. Competitive inhibition occurs when a substrate and the inhibitor compete for active site on the enzyme
3. Non-competitive inhibition of an enzyme can be overcome by adding a large amount of substrate
4. Non-competitive inhibitors often bind to the enzyme irreversibly
The structure that helps in cell wall formation, DNA replication and respiration in bacteria is :
1. Mesosome
2. Chromatophores
3. Pilus
4. Nucleoid
Cell membrane carbohydrates participate in
1. transporting substances between two protein layers
2. cell-to-cell recognition
3. attaching the membrane to cytoskeleton
4. cell adhesions
The point of contact between paired chromatids during meiosis, resulting in a cross-shaped configuration and representing the cytological manifestation of crossing over is called:
1. Centromere
2. Centrosome
3. Chiasmata
4. Tetrad
Organisms prefer sexual mode of reproduction in adverse conditions because:
1. It leads to a rapid proliferation of numbers
2. It requires two individuals that can support the progeny
3. It is less energy consuming than the asexual mode of reproduction
4. It provides protection and increases variations that may help progeny to survive
A molecule of ATP is structurally most similar to :
1. RNA nucleotide
2. DNA nucleotide
3. amino acid
4. fatty acid
In feedback inhibition, a metabolic pathway is switched off by:
1. a rise in temperature
2. lack of a substrate
3. accumulation of the end product
4. competitive inhibition
The unique properties of each amino acid is determined by its particular :
1. R group
2. amino group
3. finds of peptide bond
4. number of bonds to other amino acids
If there were 4 chromosomes present during prophase I, how many chromosomes are there in each cell at the end of anaphase II?
1. 2
2. 4
3. 8
4. 16