Oogenesis and spermatogenesis produce gametes. What is the correct sequence of events in gamete formation?
Correct Answer: \( \boxed{\mathbf{C}} \)
During gametogenesis, germ cells first undergo mitosis to increase their number, followed by cell growth. They then divide by meiosis to produce haploid cells, which finally undergo differentiation to form mature sperm or egg cells.
The diagram below shows a cross-section of a flower with a part labelled Z.
Which option correctly identifies the structure labelled Z?
A. Structure Z is the anther, which is part of the stamen.
B. Structure Z is the stigma, which is part of the stamen.
C. Structure Z is the anther, which is part of the carpel.
D. Structure Z is the stigma, which is part of the carpel.
Flowering plants can use either self-pollination or cross-pollination. Which plants are most likely to cross-pollinate?
Correct Answer: \( \boxed{\mathbf{D}} \)
Plants that are either male or female (dioecious) cannot self-pollinate because each plant has only one type of reproductive organ. Therefore, pollen must be transferred between different plants, making cross-pollination essential.
