Cell walls commonly are classified into two major types. This classification is based not on structural or biochemical differences;

A) primary walls and

B) secondary walls

i) walls formed during cell growth

ii) walls that are formed after cell enlargement stops

iii) multilayered walls that are strengthened and waterproofed by lignin

iv) Usually they are thin and simple, but sometimes may be thick and multilayered, such as those found in collenchyma or in the epidermis

v) highly specialized in structure and composition, reflecting the differentiated state of the cell

Which of the following correctly represents features of primary and secondary walls?

TLS Online TPP Program

#Question id: 27375

#Unit 1. Molecules and their Interaction Relevant to Biology

An atom of sodium has an atomic number of 11 and a mass number of 23. Which of the following statements is correct?

TLS Online TPP Program

#Question id: 23832

#Unit 2. Cellular Organization

How many head domains are present in myosin I?

TLS Online TPP Program

#Question id: 2724

#Unit 2. Cellular Organization

When DNA is compacted by histones into 10 nm and 30 nm fibers, the DNA is unable to interact with proteins required for gene expression. Therefore, to allow for these proteins to act, the chromatin must constantly alter its structure. Which processes contribute to this dynamic activity?

TLS Online TPP Program

#Question id: 1846

#Unit 4. Cell Communication and Cell Signaling

A small protein subunit used in a vaccine can fail to stimulate T-cell immunity because of:

TLS Online TPP Program

#Question id: 32408

#Unit 1. Molecules and their Interaction Relevant to Biology

What would result if 14CO₂ were incorporated into the TCA cycle via the pyruvate carboxylase reaction.