Question 1

Which statement best explains why plants and animals represent independent experiments in multicellular evolution?

Accepted Answer

Multicellularity evolved more than once, and the developmental genes in plants and animals are not related.

Question 2

In the shoot meristem of Arabidopsis thaliana, which zone is responsible for maintaining the reservoir of stem cells?

Accepted Answer

Central zone

Question 3

Which combination of homeotic gene activities according to the ABC model specifies the identity of petals in Arabidopsis flowers?

Accepted Answer

$A + B$

Question 4

A class B mutant in Arabidopsis would result in which transformation of floral organs?

Accepted Answer

Sepals replace petals and carpels replace stamens

Question 5

If a triple mutant lacking A, B, and C class gene activities is produced in Arabidopsis, what is the expected phenotype of the floral organs?

Accepted Answer

All whorls resemble leaves

Question 6

Which gene in Arabidopsis is responsible for preventing B class gene expression in the fourth whorl?

Accepted Answer

SUPERMAN

Question 7

During double fertilization in flowering plants, what is the ploidy of the endosperm formed?

Accepted Answer

$3n$

Question 8

Which stage of plant embryo development is characterized by the formation of two distinct poles (shoot and root)?

Accepted Answer

Maturing bipolar embryo

Question 9

In the ABC model, which gene activity is mutually exclusive with A class activity and terminates further flower initiation?

Accepted Answer

C class

Question 10

Which of the following best describes the difference between totipotent and pluripotent cells?

Accepted Answer

Totipotent cells can form any cell type, including extraembryonic tissues; pluripotent cells can form many but not all cell types.

Question 11

A grape cultivar is propagated by cuttings rather than seeds. What is the genetic consequence of this agricultural practice?

Accepted Answer

The propagated plants will be genetically identical to the parent.

Question 12

Which gene in C. elegans represses the cell death program, and what is its human homolog?

Accepted Answer

Ced9; Bcl2

Question 13

In the context of programmed cell death, which gene encodes the death program in humans?

Accepted Answer

Bax

Question 14

Which of the following is true regarding the evolution of ABC genes in plants?

Accepted Answer

B and C class genes are not found in earlier plant lineages such as ferns and bryophytes.

Question 15

A sheep is cloned by nuclear transplantation. Which statement best describes the genetic identity of the resulting animal?

Accepted Answer

It is genetically identical to the nucleus donor.

Question 16

In C. elegans, mutations that inhibit apoptosis result in which of the following outcomes?

Accepted Answer

Survival of cells that are normally fated to die

Question 17

Which combination of gene activities is present in the third whorl of a wild-type Arabidopsis flower according to the ABC model?

Accepted Answer

$B + C$

Question 18

If a plant has a loss-of-function mutation in both A and B class genes, what floral organ identity will be present in all whorls?

Accepted Answer

C class organ identity (carpels) in all whorls

Question 19

Which of the following best describes the role of meristems in plant development?

Accepted Answer

Meristems are organized groups of pluripotent cells that generate organs and maintain stem cells.

Question 20

Which Nobel Prize-winning discovery was made using C. elegans as a model system?

Accepted Answer

The discovery of cell lineage and the first cell death gene

18. Developmental Genetics Plants

Study Guide - Practice Questions