Defense

Question 1

Title of the Study

Answer 1

Cytotoxic and Genotoxic Effects of Baking Powder Using Chromosomal Aberration Assay in Onion (Allium cepa) root tip cells

Question 2

What brand of baking powder was used in the study

Answer 2

Calumet baking powder

Question 3

concentrations of baking powder solutions used in the study

Answer 3

0.1%
1%
5%
10%

Question 4

What did the mitotic index and percentage of chromosomal aberrations assessed to determine

Answer 4

impact of baking powder on cell division and genetic stability

Question 5

were the results significant or not significant for dose-dependent decrease in mitotic activity?

Answer 5

significant

31.80% in the control

23.40%
8.80%
4.90%
1.20%

Question 6

chromosomal aberrations increased with concentration, ranging from _____ in the lowest treatment to ____ in the highest.

Answer 6

0.7%
5.2%

Question 7

What were the statistical tools used and what are their results

Answer 7

1. one-way ANOVA - highly significant differences (p < 0.05) across all groups.
2. Dunnett’s test (post-hoc test) - confirmed that each treatment significantly differed from the control for both the mitotic index and chromosomal aberrations.

Question 8

What were the observed abnormalities that indicated cytogenic damage

Answer 8

binucleated cells
nuclear lesions
sticky metaphase

Question 9

Why did we use one-way ANOVA

Answer 9

One-way analysis of variance (ANOVA) is a statistical method that compares the means of two or more groups to determine if there are statistically significant differences between them

Question 10

Why did we use Dunnett’s test

Answer 10

it is a statistical method used to compare multiple treatment groups to a control group.

Question 11

what are nuclear lesions

Answer 11

Abnormalities in the structure or integrity of the nucleus, such as micronuclei, nuclear buds, or fragmented nuclei.

Question 12

define sticky metaphase

Answer 12

a chromosomal aberration that occurs when chromosomes become entangled, or “sticky”, during the metaphase stage of cell division

Question 13

why did we use Allium cepa root assay

Answer 13

It is simple, reliable, cost-effective, and correlates with mammalian systems which makes it indispensable for toxicological studies.

Question 14

what is the gap bridged by the study

Answer 14

the scope of the findings is in related studies is limited, particularly in terms of varying concentrations and exposure durations, emphasizing the need for further comprehensive research.

Question 15

how did we evaluate the cytotoxic and genotoxic effects of baking powder on Allium cepa root tip cells

Answer 15

by examining chromosomal aberrations and assessing mitotic indices across different concentrations.

Question 16

Calumet serving suggestion

Answer 16

0.6 g

Question 17

Why do we need to use Carnoy’s solution 1 (Farmer’s solution)?

Answer 17

fixative to preserve the cellular and chromosomal structures of onion root tip cells for microscopic examination

Question 18

Why do we use acetocarmine stain?

Answer 18

DNA and RNA specific biological stain

Question 19

why do we need to use 1 N hydrochloric acid

Answer 19

pre-treatment step before staining to prepare the onion root tip cells for microscopic examination. Its primary role is to soften the cell walls and aid in the breakdown of cytoplasmic material, facilitating better access to and visualization of chromosomes.

Question 20

why do we need to squash the samples gently?

Answer 20

Violent squashing could tear, distort, or clump the chromosomes, making it difficult to identify mitotic stages or chromosomal abnormalities.

Question 21

mitotic index formula

Answer 21

Mitotic index = (# of dividing cells/total number of cells counted) x 100

Question 22

formula for percentage aberration

Answer 22

% aberration = (Total # of aberrant cells/Total # of cells counted) x 100

Question 23

What is Standard error of the mean?

Answer 23

is a statistical measure that quantifies the variability of sample means from the true population mean. It reflects how much the sample mean (average) is likely to differ from the population mean due to random sampling. The smaller the SEM, the more precise the sample mean is as an estimate of the population mean.

Question 24

frequency of aberration in increasing concentrations

Answer 24

0.1%
0.7%
1.5%
2.7%
5.2%

Question 25

p-value for the mitotic index

Answer 25

1.90×10^⁻9

Question 26

p-value for chromosomal aberrations

Answer 26

5.17x10^-7

Question 27

what are type I errors

Answer 27

false positives

A false positive occurs when a statistical test incorrectly indicates that a result is significant when, in reality, there is no true effect or difference. In hypothesis testing, it means rejecting the null hypothesis (𝐻0) when it is actually true.

Question 28

why do we need to adjust the alpha level

Answer 28

Adjusting the alpha level to 0.0125 ensures the findings are statistically reliable, reducing the risk of Type I errors (false positives) that could arise from multiple comparisons.

Question 29

clastogenic means

Answer 29

causing breaks in chromosomes, which can result in the loss or rearrangement of chromosome segments.

Question 30

Binucleated cells are caused by inhibition of the
_______, an array of actin filaments and
microtubules that serve to transport Golgi vesicles
holding cell wall precursors

Answer 30

phragmoplast

Question 31

what is the likely cause of chromosome bridges

Answer 31

This might have been caused by the physical adhesion of chromosomal proteins

Question 32

what is chromosome stickiness

Answer 32

an interchromosomal linkage of sub-chromatid strands
coupled with excessive formations of nucleoproteins and
inappropriate protein-protein interaction.

Question 33

accumulation of micronuclei arise from acentric
chromosome fragments caused by unrepaired double
strand breaks (DSBs) and chromosomal lagging, which
are specifically products of aberrant kinetochore
microtubule attachments and defects in mitotic spindle
assembly.