20. Development

Which of the following statements is true?

Cytoplasmic determinants __________.

Cells can influence each other's development by a process known as __________.

Instead of developing a head and a tail, an abnormal Drosophila embryo develops two tails. This is most likely due to __________.

Cell differentiation is first observable when __________.

During the process of differentiation, cells __________.

__________ can give rise to any type of cell whereas __________ can give rise to a subset of cell types.

The similarity of the homeobox in many different kinds of organisms is evidence __________.

The highly conserved sequence element present within homeotic genes is called the __________.

What are the two main genetic and cellular mechanisms that underlie differentiation?

Which of the following statements is true?

The products of Hox genes __________.

What is apoptosis?a. an experimental technique used to kill specific cellsb. programmed cell death that is required for normal developmentc. a pathological condition observed only in damaged or diseased organismsd. a developmental mechanism unique to the roundworm C. elegans

Which of the following occurs when a covalent bond forms?a. Electrons in valence shells are transferred from one atom to another.b. Electrons in valence shells are shared between atoms.c. Partial charges on polar molecules interact.d. Nonpolar molecules are pushed together.by surrounding water molecules.

In adult animals, are a source of undifferentiated cells that can divide to produce cells that can specialize.