4.7 Cell Biology and Genetics

ATI TEAS 7 Nursing Admission

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1 Introduction to the ATI TEAS 7

1.1 About the ATI TEAS 7 Exam 1.2 Content Area Breakdown 1.3 Scoring and Program Requirements 1.4 Building Your TEAS Study Plan

2 Reading

2.1 Identifying the Main Idea 2.2 Making Inferences and Drawing Conclusions 2.3 Summarizing and Paraphrasing 2.4 Understanding Text Structure 2.5 Author's Purpose, Tone, and Point of View 2.6 Evaluating Arguments, Evidence, and Credibility 2.7 Integrating Information and Interpreting Graphics 2.8 TEAS Reading Strategies, Pacing, and Practice

3 Mathematics

3.1 Whole Numbers and Basic Operations 3.2 Fractions 3.3 Decimals and Percentages 3.4 Ratios and Proportions 3.5 Algebra and Equations 3.6 Measurement and Unit Conversions 3.7 Statistics and Data Interpretation 3.8 Geometry Basics

4 Science

4.1 The Cardiovascular System 4.2 The Respiratory System 4.3 The Digestive System 4.4 The Nervous System 4.5 The Musculoskeletal System 4.6 The Urinary and Reproductive Systems 4.7 Cell Biology and Genetics 4.8 Chemistry Basics 4.9 Scientific Reasoning and the Scientific Method

5 English & Language Usage

5.1 Grammar and the Parts of Speech 5.2 Sentence Structure 5.3 Punctuation 5.4 Spelling and Word Usage 5.5 Vocabulary in Context and Word Parts 5.6 Paragraph Organization and the Writing Process 5.7 Formal vs. Informal Language, Audience, and Tone 5.8 TEAS English Section Strategies and Pacing

Free exam prep ATI TEAS 7 Practice Questions 120 questions Study Guide 37 topics Cheat Sheet 113 facts Flashcards 50 cards

4.7 Cell Biology and Genetics

Key Takeaways Explain This Topic AI

Eukaryotic cells have a membrane-bound nucleus and organelles; prokaryotic cells (bacteria) do not

Mitochondria make ATP, ribosomes build proteins, the nucleus stores DNA, and the cell membrane controls transport

Passive transport (diffusion, facilitated diffusion, osmosis) needs no energy; active transport uses ATP to move against the gradient

Mitosis makes 2 identical diploid cells for growth and repair; meiosis makes 4 genetically different haploid gametes

DNA bases pair A-T and G-C (RNA uses U for T); a heterozygous parent (Bb) passes each allele to 50% of gametes Last updated: October 2026

The Cell as the Unit of Life Every living thing is built from cells, and the ATI TEAS 7 Science section expects you to know what each organelle does, how substances cross the membrane, how cells divide, and how traits are inherited. These topics tie directly to nursing: drug action depends on membrane transport, cell division explains both healing and cancer, and genetics underlies inherited disease. Prokaryotic vs. Eukaryotic Cells

Feature Prokaryotic Eukaryotic Nucleus No membrane-bound nucleus Membrane-bound nucleus Size Smaller (1–10 micrometers) Larger (10–100 micrometers) Organelles Few, none membrane-bound Many membrane-bound Examples Bacteria, archaea Plants, animals, fungi The single biggest distinction: prokaryotes have no nucleus , so their DNA floats freely in the cytoplasm. Eukaryotes wall their DNA inside a nucleus. Eukaryotic Organelles and Their Jobs

Organelle Function Nucleus Stores DNA and directs cell activities Mitochondria Produce ATP through cellular respiration (the "powerhouse") Ribosomes Synthesize proteins Endoplasmic reticulum Rough ER makes proteins; smooth ER makes lipids Golgi apparatus Modifies, packages, and ships proteins Lysosomes Digest waste and foreign material Cell membrane Controls what enters and exits Cytoplasm Gel-like fluid holding the organelles Plant cells add three structures animal cells lack: a cell wall (cellulose), chloroplasts (photosynthesis), and a large central vacuole (storage and structure). The Cell Membrane and Transport The fluid mosaic model describes the membrane as a phospholipid bilayer (water-loving heads facing out, water-fearing tails inside) studded with proteins, cholesterol for fluidity, and surface carbohydrates for recognition. Expect questions on how molecules cross it.

Type Energy? Direction Example Simple diffusion No High to low concentration O2, CO2 Facilitated diffusion No High to low (via proteins) Glucose Osmosis No Water toward higher solute Water balance Active transport Yes (ATP) Low to high concentration Sodium-potassium pump The trick to every transport question: passive transport moves substances down the gradient and costs no energy, while active transport pushes against the gradient and requires ATP. Osmosis is simply the diffusion of water.

DNA, RNA, and Replication

Feature DNA RNA Structure Double helix Single strand Sugar Deoxyribose Ribose Bases A, T, G, C A, U, G, C Job Stores genetic information Carries out protein synthesis Know the base-pairing rules : A pairs with T and G pairs with C in DNA; RNA swaps in uracil (U) for thymine. In DNA replication , the enzyme DNA polymerase unzips the helix and builds a matching strand on each half, producing two identical molecules before division. Protein Synthesis in Two Steps Transcription (in the nucleus) — DNA is copied into messenger RNA (mRNA). Translation (at the ribosome) — the mRNA code is read in three-base units to assemble amino acids into a protein. Cell Division: Mitosis vs. Meiosis

Feature Mitosis Meiosis Daughter cells 2 4 Chromosome number Diploid (full set) Haploid (half set) Genetically Identical to parent Different (genetic variation) Purpose Growth and repair Produce gametes Mitosis proceeds through prophase, metaphase, anaphase, and telophase (PMAT), producing two identical diploid cells for growth and tissue repair. Meiosis has two rounds of division and produces four genetically different haploid gametes. The variation comes from crossing over (homologous chromosomes swap segments during prophase I) and independent assortment . Genetics and the Punnett Square An allele is a version of a gene. A dominant allele (capital letter) shows its trait with just one copy; a recessive allele (lowercase) needs two copies to appear. Genotype is the genetic makeup (e.g., Bb); phenotype is the visible trait. A Punnett square predicts offspring ratios. Worked Example: Cross two heterozygous brown-eyed parents (Bb x Bb), where B (brown) is dominant over b (blue). Each parent passes B to half its gametes and b to the other half. The square gives: 1 BB : 2 Bb : 1 bb Genotype ratio 1:2:1 ; phenotype ratio 3 brown : 1 blue (75% brown, 25% blue). A blue-eyed child (bb) is possible only because each parent carried one recessive b allele — exactly the kind of reasoning the TEAS rewards.

Offspring Phenotypes from a Bb x Bb Cross

Test Your Knowledge

Which organelle produces ATP through cellular respiration?

Ribosome

Golgi apparatus

Mitochondria

Lysosome Check Answer Need a hint? AI

Test Your Knowledge

Which process moves a substance from low concentration to high concentration and requires energy?

Simple diffusion

Osmosis

Facilitated diffusion

Active transport Check Answer Need a hint? AI

Test Your Knowledge

What is the result of meiosis?

Two identical diploid cells

Four identical haploid cells

Two genetically different diploid cells

Four genetically different haploid cells Check Answer Need a hint? AI

Test Your Knowledge Fill in the Blank

In DNA, the base adenine (A) always pairs with the base ___. Type your answer below Check Answer Need a hint? AI

Test Your Knowledge

Two parents are both heterozygous (Bb) for a trait where B is dominant. What fraction of offspring is expected to show the recessive phenotype?

1/4

1/2

3/4 Check Answer Need a hint? AI

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