vQUESTION 2 [53 marks]

Question

Question 2.1 [9 marks]
Study the diagram below which shows the structure of a flower and answer the
questions that follow.
Figure 4: Structure of a flower
Question 2.1.1 [1 mark]
Which phylum does the above plant belong to?
Question 2.1.2 [2 marks]
Identify the parts labelled 1 and 2.
Question 2.1.3 [1 mark]
What do we call part Y?
12
Question 2.1.4 [3 marks]
Using the number only, identify the following:
a) Structure where a seed can form.
b) The part that receives pollen.
c) The part where pollen is produced.
Question 2.1.5 [2 marks]
A seed bank in Cape Town has been storing seeds of a rare and endangered
plant. To keep the seeds fresh, 90 of the seeds of this plant were selected to be
grown. Of the 90 seeds, only 50 germinated. What percentage of the seeds was
not fertile? Show all your calculations.
Question 2.2 [19 marks]
Study the diagram below and answer the questions that follow.
Figure 5: Diagram showing evolutionary relationships.
Question 2.2.1 [2 marks]
Name the diagrammatic representation of evolutionary relationships shown
above.
13
Question 2.2.2 [2 marks]
Identify the missing labels a and b.
Question 2.2.3 [9 marks]
Tabulate FOUR differences between Bryophytes and Angiosperms.
Question 2.2.4 [6 marks]
Describe in detail how pollination occurs in angiosperms.
Question 2.3 [25 marks]
During the holidays a learner forgot to take his lunch box out of his school
bag. Inside were some uneaten sandwiches. At the beginning of the
following term, his mother found black, furry patches growing on the leftover
bread.
Figure 6: Left-over bread
Question 2.3.1 [2 marks]
Identify the organism most likely to be responsible for the growth on the bread.
Question 2.3.2 [2 marks]
Write the aim of the investigation.
14
Question 2.3.3 [2 marks]
State:
a. The independent variable
b. The dependent variable
Question 2.3.4 [2 marks]
State the relationship between temperature and the growth of bread mould.
Question 2.3.5 [6 marks]
Name THREE conditions that made the lunch box a suitable environment for the
organism mentioned in 3.1 to grow and give a reason for each of your
conditions.
Question 2.3.6 [3 marks]
State THREE ways in which the learner ensured that the results were reliable.
Question 2.3.7 [8 marks]
The table below shows the time it took the bread to mould.
Time (hours) Number of black patches
24 2
30 4
36 6
48 10
Plot a line graph to show the amount of black patches that appeared on the
bread over time.

Answer 1

Question 2.1 [9 marks]

Question 2.1.1 [1 mark]
Which phylum does the above plant belong to?
Answer: Angiosperms (or Anthophyta).

Question 2.1.2 [2 marks]
Identify the parts labelled 1 and 2.
Answer:

1. Stamen
2. Pistil (or Carpel)

Question 2.1.3 [1 mark]
What do we call part Y?
Answer: Petal

Question 2.1.4 [3 marks]
Using the number only, identify the following:
a) Structure where a seed can form.
Answer: (Usually would be the ovary - number associated with it)
b) The part that receives pollen.
Answer: (Usually the stigma - number associated with it)
c) The part where pollen is produced.
Answer: (Usually the anther - number associated with it)

Question 2.1.5 [2 marks]
A seed bank in Cape Town has been storing seeds of a rare and endangered plant. To keep the seeds fresh, 90 of the seeds of this plant were selected to be grown. Of the 90 seeds, only 50 germinated. What percentage of the seeds was not fertile? Show all your calculations.
Answer:
Total seeds = 90
Germinated seeds = 50
Non-germinated seeds = 90 - 50 = 40
Percentage not fertile = (Non-germinated seeds / Total seeds) × 100
= (40 / 90) × 100 ≈ 44.44%

Question 2.2 [19 marks]

Question 2.2.1 [2 marks]
Name the diagrammatic representation of evolutionary relationships shown above.
Answer: Phylogenetic tree (or cladogram).

Question 2.2.2 [2 marks]
Identify the missing labels a and b.
Answer:
a. Common ancestor (or Node)
b. Divergence (or Speciation event)

Question 2.2.3 [9 marks]
Tabulate FOUR differences between Bryophytes and Angiosperms.

| Feature | Bryophytes | Angiosperms | |----------------------|-----------------------------------|---------------------------------| | Vascular System | Absent | Present | | Seed Formation | No seeds (spores) | Seeds enclosed in fruits | | Habitat Adaptation | Usually found in moist environments | Can thrive in various habitats | | Reproductive Structures| Gametangia (antheridia & archegonia) | Flowers (stamens & carpels) |

Question 2.2.4 [6 marks]
Describe in detail how pollination occurs in angiosperms.
Answer:
Pollination in angiosperms involves the transfer of pollen from anthers (male gametes) to the stigma (female receptive part) of a flower. This process can occur through various agents:

• Wind Pollination: Pollen is carried by wind currents to other flowers.
• Insect Pollination: Insects (e.g., bees) visit flowers to collect nectar and, in the process, brush against the anthers, picking up pollen and transferring it to the stigma of another flower.
• Animal Pollination: Other animals, such as birds and bats, may also assist in pollen transfer, especially in tropical regions.
• Water Pollination: In some aquatic plants, pollen can be transported by water. Once the pollen grain lands on a compatible stigma, it germinates, and a pollen tube forms, growing down the style into the ovary where fertilization occurs, leading to seed development.

Question 2.3 [25 marks]

Question 2.3.1 [2 marks]
Identify the organism most likely to be responsible for the growth on the bread.
Answer: Mould (commonly, Penicillium or Aspergillus species).

Question 2.3.2 [2 marks]
Write the aim of the investigation.
Answer: To investigate the growth of mould on bread over time under specific environmental conditions.

Question 2.3.3 [2 marks]
State:
a. The independent variable
Answer: Time (duration the bread is left uneaten).
b. The dependent variable
Answer: The number of black mould patches on the bread.

Question 2.3.4 [2 marks]
State the relationship between temperature and the growth of bread mould.
Answer: Generally, the growth of bread mould increases with temperature, as warmer temperatures promote microbial activity.

Question 2.3.5 [6 marks]
Name THREE conditions that made the lunch box a suitable environment for the organism mentioned in 2.3.1 to grow and give a reason for each of your conditions.

1. Moisture:
   Reason: Mould requires moisture to grow and reproduce, as it thrives in humid environments.

2. Nutrient Availability:
   Reason: The leftover bread serves as a rich source of nutrients for the mould to absorb, facilitating growth.

3. Warm Temperature:
   Reason: Mould tends to grow faster in warm conditions, and the insulating nature of the lunch box may have contributed to a warm and stable environment.

Question 2.3.6 [3 marks]
State THREE ways in which the learner ensured that the results were reliable.
Answer:

1. Consistent Measurement: By measuring growth (black patches) at regular time intervals.
2. Controlling Environment: Keeping the lunch box in the same temperature and humidity conditions to minimize variations.
3. Replicates: If multiple pieces of bread were tested, averaging the results helps ensure accuracy.

Question 2.3.7 [8 marks]
The table below shows the time it took the bread to mould. Plot a line graph to show the amount of black patches that appeared on the bread over time.
(Note: Since I cannot visually plot graphs, I will describe how to plot this graph.)

Instructions to Plot:

1. X-axis (Horizontal): Time (hours) with scale marking from 0 to 50.
2. Y-axis (Vertical): Number of black patches with scale marking from 0 to 12 (or higher as needed).
3. Plot Points:
   • (24, 2)
   • (30, 4)
   • (36, 6)
   • (48, 10)
4. Connect the Points: Draw a line to connect each point for visualization.

Note: Ensure to label the axes and title the graph appropriately (e.g., Time vs. Number of Black Patches on Bread).