Question

1. oogenesis produces:

a. one ovum and polar bodies
b. four equal ova
c. two diploid eggs
d. identical gametes

1. primary oocytes are arrested during:

a. prophase i
b. metaphase ii
c. anaphase i
d. telophase ii

1. meiosis ii in oocytes is completed:

a. only after fertilization
b. immediately after ovulation
c. during puberty
d. before birth

1. the asymmetry of oogenesis ensures:

a. cytoplasmic concentration in one functional ovum
b. equal division among all daughter cells
c. symmetric cytokinesis
d. equal organelle distribution

1. the structure that produces sperm in flowering plants is the:

a. anther
b. ovule
c. ovary
d. embryo sac

1. the structure that produces egg cells in flowering plants is the:

a. ovary
b. anther
c. pollen grain
d. filament

1. the male gametophyte in flowering plants is represented by:

a. the pollen grain
b. the anther
c. the sperm cell nucleus
d. the pollen tube only

Explanation:

• 37: Oogenesis is the process of female gamete formation. During oogenesis, one primary oocyte undergoes meiosis. Meiosis I results in one secondary oocyte and one polar body. Meiosis II of the secondary oocyte (after fertilization) produces one ovum and another polar body. So, oogenesis produces one ovum and polar bodies.
• 38: Primary oocytes are arrested in prophase I of meiosis. This arrest occurs during fetal development and is maintained until puberty when some primary oocytes resume meiosis.
• 39: Meiosis II in oocytes is completed only after fertilization. The secondary oocyte is released during ovulation and remains arrested in metaphase II. When a sperm penetrates the secondary oocyte, meiosis II is completed.
• 40: The asymmetry of oogenesis (unequal cytoplasmic division) ensures that most of the cytoplasm (containing nutrients, organelles etc.) is concentrated in one functional ovum. This is important as the ovum needs to support the early stages of embryonic development.
• 41: In flowering plants, the anther is the part of the stamen (male reproductive organ) that produces pollen grains. Each pollen grain contains sperm cells.
• 42: The ovary contains ovules. Inside the ovule, the embryo sac is formed. The embryo sac contains the egg cell. So, the ovary (as it houses the ovules which produce egg cells) is the structure that produces egg cells.
• 43: The male gametophyte in flowering plants is the pollen grain. The pollen grain contains the generative cell (which divides to form sperm cells) and the tube cell (which forms the pollen tube).

Answer:

A. One ovum and polar bodies
A. Prophase I
A. Only after fertilization
A. Cytoplasmic concentration in one functional ovum
A. Anther
A. Ovary
A. The pollen grain