Revert cell 14 to 1x2 and add total_counts=7500 cutoff line to both panels

Agent-Logs-Url: https://github.com/compbiocore/singlecell_python_workshop/sessions/6148e5ea-d7fd-48e9-8dd4-f9ded9ac6250

Co-authored-by: EricSalomaki <6400723+EricSalomaki@users.noreply.github.com>

Author: Copilot

notebooks/scRNAseq_in_Python.ipynb

@@ -384,22 +384,18 @@
    "outputs": [],
    "source": [
     "# Scatter plots — visually identify outlier cells\n",
-    "fig, axes = plt.subplots(1, 3, figsize=(18, 4))\n",
+    "fig, axes = plt.subplots(1, 2, figsize=(12, 4))\n",
     "\n",
     "sc.pl.scatter(adata, x='total_counts', y='pct_counts_mt', ax=axes[0], show=False)\n",
     "axes[0].axhline(5, color='red', linestyle='--', label='5% MT threshold')\n",
+    "axes[0].axvline(7500, color='green', linestyle='--', label='7500 total_counts cutoff')\n",
     "axes[0].legend()\n",
     "\n",
     "sc.pl.scatter(adata, x='total_counts', y='n_genes_by_counts', ax=axes[1], show=False)\n",
     "axes[1].axhline(2500, color='red', linestyle='--', label='2500 gene threshold')\n",
+    "axes[1].axvline(7500, color='green', linestyle='--', label='7500 total_counts cutoff')\n",
     "axes[1].legend()\n",
     "\n",
-    "# Standard total_counts cutoff — flag cells with very low library size\n",
-    "sc.pl.scatter(adata, x='total_counts', y='n_genes_by_counts', ax=axes[2], show=False)\n",
-    "axes[2].axvline(500, color='green', linestyle='--', label='500 UMI min (total_counts)')\n",
-    "axes[2].set_title('total_counts — standard cutoff')\n",
-    "axes[2].legend()\n",
-    "\n",
     "plt.tight_layout()\n",
     "plt.show()\n"
    ]