The G1 checkpoint in the cell cycle makes suit that A the D

The G_1 checkpoint in the cell cycle makes suit that ______. A. the DNA is duplicated B. all chromosomes are aligned on the metaphase plate C. the DNA is not damaged D. centrosome is duplicated In addition to CO_2, the Krebs (citric acid) cycle also produces ______. A. ethanol and NAD^+ B. glucose and O_2 C. pyruvate and ATP D. NADH and FADH_2 Which of the following events occur(s) during produces I of meiosis I? A. synapsis B. formation of tetrads C. crossing over D. all of the above In the electron transport chain (ETC), H^+ pumps use the energy of electrons to pump H^+ from the ______ to the ______ by ______. A. mitochondrial matrix ... intermembrane space ... facilitated diffusion B. mitochondrial matrix ... cytoplasm ... active transport C. intermembrane space ... mitochondrial matrix ... facilitated diffusion D. mitochondrial matrix ... intermembrane space ... active transport Photosystem I uses its high-energy electrons to make ______. A. O_2 B. ATP C. NADPH D. CO_2 What stage of meiosis is this cell in? A. telophase I B. metaphase I C. prophase I D. anaphase I The ATP made during glycolysis is generated by which of the following? A. electron transport chain B. chemiosmosis C. subtract-level phosphorylation D. oxidative phosphorylation Which of the following factors affect(s) cell division? A. anchorage dependence of growth B. growth factors C. density-dependent inhibition D. all of the above

Solution

8: C: The G₁ checkpoint in the cell cycle makes sure that DNA is not damaged.
9: D: In addition to CO₂, the Kreb cycle also produced NADH and FADH₂.
10: D: Prophase I of meiosis is characterised by pairing of homologous chromosomes (synapsis), formation of tetrad and crossing over.
11: D: In ETS, proton pump uses the energy of electrons to pump the protons from mitochondrial matrix to intermembrane space by active transport.