The Antibody Surface Involved in Antigen Binding Varies Depending on the Size

question 21

Multiple Choice

The antibody surface involved in antigen binding varies depending on the size and nature of the antigen. This surface can be concave or flat, and sometimes, can have extended protrusions. This is accomplished by:

• A) Flexibility in the hinge regions of the antibody allowing rotation of the antigen-binding sites
• B) Some antibodies using V region framework sequences instead of the CDRs to bind antigen
• C) The ability of different CDR sequences to form many structurally distinct shapes and surfaces
• D) The ability of the same heavy chain to pair with different light chains
• E) The differential usage of κ versus λ light chains, as κ chains form concave binding sites whereas λ chains make flatter surfaces

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Definitions:

Evolved

Refers to the cumulative changes in heritable traits of a population over successive generations, leading to biodiversity.

Acheulean Technology

A Stone Age technology characterized by distinctive oval and pear-shaped hand-axes, associated with early humans, particularly Homo erectus.

Genus Homo

The genus to which modern humans belong, characterized by higher mental faculties, upright posture, and bipedal locomotion.

Oldowan Tools

The earliest known stone tool industry, dating back to about 2.6 million years ago, associated with Homo habilis and used by early hominins for cutting, scraping, and processing animal and plant materials.