Cell numbers can be counted directly by all of the following except A) microscope counting chamber. B) Coulter counter. C) flow cytometer. D) turbidity

Which of the following techniques is the best way to directly count viable cells?ANSWERMeasuring the turbidity of a solutionPlate countsMeasuring the consumption of oxygenDirect microscopic counting of only motile cells

Which of these methods can be used to obtain a total cell estimate? Group of answer choices Most probably number estimations Any of the methods listed Plate counts of serial dilutions Optical density measurement

Gametes are described as ______________ cells, meaning they have _______ the number of chromosomes that are found in a typical body cell.diploidhalfhaploidthirdhaploid

An honours student needs to count the number of cells they have in a tube. They take an aliquot of the cells and dilute them 1:50 before loading 10 uL into a haemocytometer to perform a cell count. They count 4 quadrants and obtain the following counts for each quadrant: 12, 5, 17, 9.Which of the following statements is the most correct?Group of answer choicesThey should take the cells from the original flask, perform a new 1:5 dilution and repeat the cell countThe cells in the original flask are at a concentration of 5.4 x10^6 cells per mLThe cells in the original flask are at a concentration of 1.08 x 10^5 cells per mLThey should take the cells from the original flask, perform a new 1:100 dilution and repeat the cell count

c) A student wanted to find out more about the cell cycle. The student made a slide of an onion root tip. She counted the number of cells in each stage of the cell cycle in one field of view. The table below shows the results.Stages in the cell cycleNon-dividing cells Stage 1 Stage 2 Stage 3 Stage 4 TotalNumber of cells209 4 2 1 36 Each stage of the cell cycle takes a different amount of time. Which stage is the fastest in the cell cycle? Give a reason for your answer. Stage _____________________ Reason ____________________________________________________________ ___________________________________________________________________ (2) Page 11 of 16the genetic material and subcellular organelles are duplicating and then are moving to oppositesides of the cell where the cytoplasm then then divides resulting in the formation of twodaughter cells. in photograph A the cell are beginning to form two genetically identical daughter cells but are still connected via a shared membrane(d) The cell cycle in an onion root tip cell takes 16 hours. Calculate the length of time Stage 2 lasts in a typical cell. Give your answer to 2 significant figures. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Time in Stage 2 = ________________________ minutes (3) (e) Bacteria such as Escherichia coli undergo cell division similar to mitosis. Figure 2 shows a growth curve for E. coli grown in a nutrient broth. Figure 2What type of cell division causes the change in number of E. coli cells at P? ___________________________________________________________________ (1) Page 12 of 16(f) Suggest why the number of cells levels out at Q. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________