Question

Which of the following should be used as an explant to generate a disease-free plant?

• A. Ovary cell
• B. Anther
• C. Young embryo
• D. Shoot tip

Answer 1

The correct option is D

Shoot tip

The correct option is D

Explanation of the correct option:

1. The tissues that can first renew the plant are the shoot tips.
2. A plant's isolated shoot-tip culture has the ability to proliferate and reproduce clone plants in the form of an axillary bud, protocorm-like body, or shoot primordium.
3. Explants/shoot tips are made up of the shoot apical meristem, a number of 1 cm long leaf primordia, and unexpanded leaves in various developmental stages.
4. The explants are injected into a cytokinin-supplemented medium during shoot-tip culture.

Explanation of the incorrect options:

Option A:

1. The female gametes, or egg cells, are produced and periodically released from the ovaries.
2. In the body, the ovaries serve two major reproductive purposes. They generate the reproductive hormones estrogen and progesterone as well as oocytes (eggs) for fertilization.

Option B:

1. The anther is a structure that may be found in the stamen or androecium, the male reproductive component of the flower.
2. It has a knob-like shape made up of two lobes that are often connected by connective tissue.
3. Within the microsporangia, which later turns into a pollen sac, it carries the pollen grains.

Option C:

1. The embryo (the young plant) and cotyledons are found inside the seed.
2. One portion of the embryo develops into the plant as the seed grows, whilst the other portion develops into the plant's root.

Final answer: The plant part that is used as an explant to generate a disease-free plant is the shoot tip.