General Biology - Exam 3 - Lewis 2025

:P

Physiological respiration is distinct from cellular respiration because…

Takes place in the lungs and airways

Respiratory tract is split into two parts

Upper and lower

Lungs have an ___ to increase surface area

alveoli are the interface between the physiological respiratory system and the circulatory system

Oxygen & CO2 cross the cell membrane by

Diffusion; O2 is moving down; CO2 is moving up

Different forms of physiological respiration share three qualities. 1.

Membranes that do gas exchange are kept__. 2. They are typically connect to a ___ system. 3. Animals with simple respiratory systems tend to be ___.

1. Wet. 2. Circulatory. 3. Small, flat, and wet

Absorptive properties of physiological respiration are limited by

Diffusion

What part of the cell can DNA be found in?

Nucleus 

Blueprints → ___. Nucleic Acids → ___.

Buildings. Human

What are the different parts of a nucleic acid?

Phosphate group, sugar, and base. Hydrophilic. DNA, only one OH; if there was two, it would be RNA.

A strand of nucleotides (AT CG) can be ___ by base pairing with another strand

Copied

Machine that copies DNA is called

DNA polymerase

When DNA polymerase makes a mistake, what occurs?

A mutation

Your genome is split into

chromosomes

Proteins in chromsomes serve to wrap up___

DNA & save space

DNA packing can be loosned by

acetylation

DNA is ___ wrapped when histone charge is positive

Tightly

Less positive histones wrap DNA

loosely

Acetylating a histone makes its charge less__

positive

DNA packing can be tightened by

methylation

A gene is a sequence of DNA that codes for a

protein

Methyl groups serve as a docking site for

chromatin remodeling proteins (compact DNA packing)

DNA must be ___ before genes are turned on

unpacked

Transcription turns ___ into ___

DNA → RNA

Single stranded DNA can be transcribed into

mRNA

Transcription can only happen in __ direction

one

RNA polymerase is the enzyme that ___ the strand of RNA

creates

Transcription goes ___

Transcription can only occur from 5’ to 3’ due to 

nucleic acid chemistry

Translation turns ___ into ___

RNA → Protein

Translation occurs ___ the nucleus

outside in the cytoplasm or the endoplasmic reticulum

Transcription occurs ___ the nucleus

inside

Translation is performed by a 

Ribosome

Translation starts when a ribosome finds an

AUG codon

Metastasis

A single tumor can seed others in a process

Tumor suppressor gene

Gene that stops cancer

Proto Oncogene

Gene with potential to cause cancer

Cancer

A disease of gene networks rather than individual genes

What are the products of mitosis?

Identical two daughter cells.

Does mitosis change the overall amount of DNA in a cell?

No.

Products of meiosis?

4 identical daughter cells