Photo AI
From the photograph it is reasonable to conclude that A - VCE - SSCE Biology - Question 1 - 2003 - Paper 1
Question 1
From the photograph it is reasonable to conclude that A. the fetus is a female. B. there are 44 autosomes. C. the DNA sequence is identical along each of the pair of... show full transcript
Worked Solution & Example Answer:From the photograph it is reasonable to conclude that A - VCE - SSCE Biology - Question 1 - 2003 - Paper 1
Step 1
A. the fetus is a female.
Answer
To conclude that the fetus is female, we can examine the chromosomes present in the karyotype. In human males, there is one X and one Y chromosome (XY), while females have two X chromosomes (XX). Since the karyotype shows two X chromosomes (indicated by X in the photograph), we conclude that the fetus is female.
Step 2
B. there are 44 autosomes.
Answer
A human karyotype consists of 46 chromosomes total, which include 22 pairs of autosomes (44 autosomes) and one pair of sex chromosomes (XX or XY). Referring to the karyotype in the photograph, we can count 22 pairs of autosomes, confirming that there are indeed 44 autosomes present.
Step 3
C. the DNA sequence is identical along each of the pair of chromosomes labelled 13.
Answer
Chromosomes that are paired (homologous chromosomes) typically have very similar sequences, but they may contain slight differences due to genetic variation. The chromosomes labelled 13 would have identical loci and gene sequences, meaning that while they are very similar, they may have small variations due to alleles. Thus, while the DNA may be nearly identical, we cannot claim they are identical without additional genetic testing.
Step 4
D. the centromeres of the chromosomes in Group A are near the ends of the chromosomes.
Answer
In karyotyping, chromosomes can be classified based on the location of their centromeres. Group A contains larger chromosomes, and closer examination of the photograph will reveal the centromeres are located closer to the ends of these chromosomes, indicating they are acrocentric. This supports the conclusion that in Group A, the centromeres are indeed near the ends.