You'll need to go into your templates and change code for both of these.
You'll want to remove this from loop-single.php:
<?php if ( get_the_author_meta( 'description' ) ) : // If a user has filled out their description, show a bio on their entries ?>
<div id="entry-author-info">
<div id="author-avatar">
<?php echo get_avatar( get_the_author_meta( 'user_email' ), apply_filters( 'twentyten_author_bio_avatar_size', 60 ) ); ?>
</div><!-- #author-avatar -->
<div id="author-description">
<h2><?php printf( esc_attr__( 'About %s', 'twentyten' ), get_the_author() ); ?></h2>
<?php the_author_meta( 'description' ); ?>
<div id="author-link">
<a href="<?php echo get_author_posts_url( get_the_author_meta( 'ID' ) ); ?>">
<?php printf( __( 'View all posts by %s <span class="meta-nav">→</span>', 'twentyten' ), get_the_author() ); ?>
</a>
</div><!-- #author-link -->
</div><!-- #author-description -->
</div><!-- #entry-author-info -->
<?php endif; ?>
the comments form edit would take a little more code messing if you're up to it. I'd recommend leaving it in so commenter's know why they're comments get filtered.