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The following information shows the chromosome number in root tip cells from a range of plants - VCE - SSCE Biology - Question 5 - 2012 - Paper 1
Question 5
The following information shows the chromosome number in root tip cells from a range of plants. Species | Common name | Chromosome number --- | --- | --- Arabidopsi... show full transcript
Worked Solution & Example Answer:The following information shows the chromosome number in root tip cells from a range of plants - VCE - SSCE Biology - Question 5 - 2012 - Paper 1
Step 1
A. common grape vine plants all show triploidy.
Answer
To assess this statement, we need to analyze the chromosome numbers for Vitis vinifera, which shows counts of 38, 57, or 76. Since none of these values is strictly indicative of triploidy (which would require a number that is a multiple of 3, such as 3n), we cannot conclude that all common grape vine plants show triploidy.
Step 2
B. only two of the three kinds of rockcress could reproduce by seed.
Answer
The species Arabidopsis holboellii (rockcress) shows varying chromosome numbers of 14, 21, or 28. Given that only even counts allow for feasible sexual reproduction through meiosis, it is reasonable to conclude that of the three chromosome numbers, only the plants with 14 or 28 chromosomes would be viable for reproduction by seed. Therefore, this statement is supported.
Step 3
C. those plants with odd numbers of chromosomes must be haploids.
Answer
This statement is not necessarily true. While haploid organisms do possess an odd number of chromosomes, having an odd number does not guarantee that the organism is haploid. In general, polyploidy can also result in odd chromosome counts, thus this rule does not apply universally.
Step 4
D. many of the flowery peppery goodness plants would be unable to carry out meiosis.
Answer
The species Nasturtium spp. shows chromosome numbers of either 32 or 64, which are both even. As such, these numbers allow for the potential of completing meiosis. However, if there are any plants with interspersed variants that are odd in chromosome number due to mutation, those could struggle with meiosis. Generally, this statement could hold validity depending on the chromosome number variability.