A student cut a piece of onion and placed it on a microscope slide. The student then placed this slide on the stage of a light microscope and looked through the eyepiece. No cells could be seen in the piece of onion. Explain two ways this method could be improved to see details of the onion cells. (b) Figure 4 shows mitosis occurring in some plant cells. (i) The cells in Figure 4 were taken from a rapidly growing part of a plant. Which part of a plant has rapidly dividing cells? (ii) Which stage of mitosis is shown in cell R? (iii) Describe two genetic similarities of the new cells that would be produced by cell Q in Figure 4. (iv) The cells in Figure 4 were heated in hydrochloric acid. State two safety precautions that should be taken when heating hydrochloric acid. (c) Explain one advantage of using an electron microscope to observe plant cells.

GCSE Edexcel Biology Combined Science Core Practical: Drawing specimen from microscope: A student cut a piece of onion a

A student cut a piece of onion and placed it on a microscope slide - Edexcel - GCSE Biology Combined Science - Question 4 - 2018 - Paper 1

Question 4

A student cut a piece of onion and placed it on a microscope slide. The student then placed this slide on the stage of a light microscope and looked through the eyep... show full transcript

Worked Solution & Example Answer:A student cut a piece of onion and placed it on a microscope slide - Edexcel - GCSE Biology Combined Science - Question 4 - 2018 - Paper 1

Step 1

Explain two ways this method could be improved to see details of the onion cells.

96%

114 rated

Answer

Use a Stain: Applying a stain, such as iodine, can enhance the visibility of cellular structures in the onion cells. Stains increase contrast, making structures such as cell walls and nuclei more evident.
Adjust Microscope Settings: The focus and magnification of the microscope can significantly impact visibility. By using a higher power objective lens, the student can achieve greater detail when observing the cells.

Step 2

Which part of a plant has rapidly dividing cells?

99%

104 rated

Answer

The part of a plant that has rapidly dividing cells is meristem.

Step 3

Which stage of mitosis is shown in cell R?

96%

101 rated

Answer

The stage of mitosis shown in cell R is metaphase.

Step 4

Describe two genetic similarities of the new cells that would be produced by cell Q in Figure 4.

98%

120 rated

Answer

Identical Genetic Material: Both new cells will have identical sets of chromosomes, containing the same genetic information as cell Q.
Same DNA Sequence: The DNA sequence in the daughter cells will be the same, as they are produced through mitosis, ensuring genetic consistency.

Step 5

State two safety precautions that should be taken when heating hydrochloric acid.

97%

117 rated

Answer

Wear Goggles: Protective eyewear is essential to avoid eye contact with the acid, which can cause serious harm.
Avoid Contact with Acid: It's important to use gloves and proper techniques to prevent skin contact with the hydrochloric acid.

Step 6

Explain one advantage of using an electron microscope to observe plant cells.

97%

121 rated

Answer

One advantage of using an electron microscope is higher resolution. This allows for detailed observation of microscopic structures that cannot be seen with a light microscope, leading to greater understanding of cell organization and function.

A student cut a piece of onion and placed it on a microscope slide - Edexcel - GCSE Biology Combined Science - Question 4 - 2018 - Paper 1

Worked Solution & Example Answer:A student cut a piece of onion and placed it on a microscope slide - Edexcel - GCSE Biology Combined Science - Question 4 - 2018 - Paper 1

Explain two ways this method could be improved to see details of the onion cells.

Which part of a plant has rapidly dividing cells?

Which stage of mitosis is shown in cell R?

Describe two genetic similarities of the new cells that would be produced by cell Q in Figure 4.

State two safety precautions that should be taken when heating hydrochloric acid.

Explain one advantage of using an electron microscope to observe plant cells.

Join the GCSE students using SimpleStudy...