Bio 3-1 - 3-6

What is Genetics?

The study of heredity; how organisms inherit traits from their parents.

What is the Genetic Code?

The molecular language that determines what cells and organisms become, contained in DNA or RNA.

What did the Chase/Hershey Experiment prove?

DNA contains the genetic codes of life; only radiated DNA, not protein, entered bacteria during infection.

What are the 3 parts of a nucleotide?

Phosphoric Acid, Deoxyribose (Sugar), Nitrogen Base.

What are the 4 nitrogen bases in DNA?

A) Adenine (A), B) Thymine (T), C) Cytosine (C), D) Guanine (G).

What is the base pairing rule in DNA?

A pairs with T, and C pairs with G.

What is the shape of DNA called?

Double Helix (looks like a twisted ladder).

What is Chromatin?

Unorganized DNA stored in the nucleus while the cell performs its functions.

What are Histones?

Special proteins that help organize and compress DNA inside the nucleus.

What are Genes?

A section of DNA that codes for a protein and determines an organism's traits.

What are Alleles?

Different forms of a gene (e.g., brown, blue, or green eyes).

What is DNA Replication?

The process of making two identical copies of DNA from the original.

What enzyme is responsible for DNA replication?

DNA Polymerase.

What does 'semi-conservative' mean in DNA replication?

Each new DNA molecule consists of one old strand and one new strand.

What are the 3 main functions of cell division?

Growth and Development, Repair, Reproduction.

What is the difference between Diploid and Haploid cells?

Diploid: Cells with a full set of chromosomes (e.g., somatic cells, created by mitosis); Haploid: Cells with half a set of chromosomes (e.g., gametes, created by meiosis).

What are the two types of reproduction?

Asexual: One parent creates identical clones (mitosis); Sexual: Two parent cells combine to form genetically unique offspring (meiosis).

What are the steps of the Cell Cycle?

Interphase, Prophase, Metaphase, Anaphase, Telophase, Cytokinesis.

What happens in Prophase?

The nucleus dissolves, and chromatin organizes into chromosomes.

What happens in Metaphase?

Chromosomes line up in the middle of the cell.

What happens in Anaphase?

Chromosomes are pulled apart by spindle fibers.

What happens in Telophase?

Chromosomes turn back into chromatin, and new nuclei form.

What happens in Cytokinesis?

The cytoplasm divides, creating two daughter cells.

What is Mitosis?

The process of a cell dividing to create two identical daughter cells.

What are the steps of Meiosis?

Meiosis I: Prophase I, Metaphase I, Anaphase I, Telophase I, Cytokinesis I; Meiosis II: Prophase II, Metaphase II, Anaphase II, Telophase II, Cytokinesis II.

What is the result of Meiosis?

Four genetically unique haploid cells: 4 sperm cells (men), 1 egg and 3 unused cells (women).

What is Crossing Over?

A process during Prophase I of meiosis where genes are exchanged between chromosomes.

What is Segregation?

The random separation of chromosomes during Anaphase II in meiosis.

What is Protein Synthesis?

The process where DNA is used to create proteins.

What are the three types of RNA?

Messenger RNA (mRNA), Transfer RNA (tRNA), Ribosomal RNA (rRNA).

What is the role of mRNA?

Carries the genetic code from DNA to the ribosome for protein synthesis.

What is a Codon?

A set of 3 nucleotides on mRNA that codes for an amino acid.

What is the role of tRNA?

Delivers amino acids to the ribosome by matching anticodons with mRNA codons.

What is the role of rRNA?

Part of ribosomes; helps bind codons to anticodons and amino acids into proteins.

What are the two stages of Protein Synthesis?

Transcription: DNA is copied into mRNA; Translation: mRNA is used to build proteins.

What happens during Transcription?

mRNA is created by RNA polymerase and exits the nucleus.

What happens during Translation?

Ribosomes use mRNA to link amino acids together into a protein.

What are Introns and Exons?

Introns: Unused parts of mRNA that are removed; Exons: Expressed parts of mRNA that are kept.

What is Genetic Engineering?

The process of altering the genetic code of organisms using recombinant DNA.

What is Recombinant DNA?

DNA from two different sources combined to create a new organism.

What is Cloning?

Creating an identical organism or cell.

What are Stem Cells?

Undifferentiated cells that can become almost any type of body cell.

What is Inheritance?

The passing of traits from parent to offspring.

What are the 3 types of allele combinations?

Homozygous Dominant (e.g., TT), Homozygous Recessive (e.g., tt), Heterozygous (e.g., Tt).

What is the Law of Dominance?

Some alleles are dominant and will show up in the organism’s phenotype.

What is the Law of Segregation?

Alleles are separated during gamete formation, leading to genetic variation.

What is the Law of Independent Assortment?

Genes for different traits are inherited independently of each other.

What is Incomplete Dominance?

When both alleles blend to form a new intermediate trait.

What is Codominance?

When both alleles are expressed equally but in separate spots (e.g., speckled pattern).

What are Mutations?

Permanent changes in DNA sequence that may lead to different traits.

What are Insertion and Deletion mutations?

Insertion: Extra nucleotides are added; Deletion: Nucleotides are removed.

What is a Karyotype?

A chart showing an organism's chromosomes.

How many chromosomes do humans have?

46 total (23 from each parent).

What are Autosomes?

Non-sex chromosomes (44 total).

What are Sex Chromosomes?

Chromosomes that determine gender (2 total, X and Y).

What are Autosomal Dominant Disorders?

Disorders caused by dominant alleles on autosomes (e.g., Dwarfism, Huntington's Disease).

What are Autosomal Recessive Disorders?

Disorders caused by recessive alleles on autosomes (e.g., Albinism, Cystic Fibrosis).

What is an example of an X-linked disorder?

Disorders like Color Blindness and Hemophilia are more common in males.