Genetics and Chromosomes

Study Notes

Genetics

Study of heredity and variation
Examines how traits are passed down from parents to offspring
Key concepts:
- Genotype: genetic makeup of an individual
- Phenotype: physical expression of an individual's genotype
- Alleles: different forms of a gene
- Dominant/recessive: relationship between alleles

Chromosomes

Thread-like structures made up of DNA and proteins
Found in the nucleus of eukaryotic cells
Characteristics:
- Number: 23 pairs in humans (46 total)
- Shape: linear, with a centromere (constricted region)
- Function: carry genetic information
Types:
- Autosomes: non-sex chromosomes
- Sex chromosomes: X and Y chromosomes, determine sex

DNA Structure

Double helix model: two complementary strands twisted together
Components:
- Sugar molecule (deoxyribose)
- Phosphate group
- Nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T)
Base pairing rules:
- A-T (adenine-thymine)
- G-C (guanine-cytosine)
Characteristics:
- Replication: semi-conservative, where each new DNA molecule contains one old strand and one new strand
- Mutation: changes in the DNA sequence

Genetics

Genetics is the study of heredity and variation, examining how traits are passed down from parents to offspring
Key concepts in genetics include genotype, phenotype, alleles, and dominant/recessive relationships

Chromosomes

Chromosomes are thread-like structures composed of DNA and proteins, found in the nucleus of eukaryotic cells
Human cells have 23 pairs of chromosomes (46 total), which are linear in shape with a centromere (constricted region)
Chromosomes carry genetic information and can be classified into two types:
- Autosomes: non-sex chromosomes
- Sex chromosomes: X and Y chromosomes, which determine an individual's sex

DNA Structure

DNA has a double helix model, consisting of two complementary strands twisted together
The components of DNA include:
- Deoxyribose (sugar molecule)
- Phosphate group
- Nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T)
Base pairing rules in DNA are:
- Adenine (A) pairs with Thymine (T)
- Guanine (G) pairs with Cytosine (C)
DNA replication is semi-conservative, resulting in new DNA molecules containing one old strand and one new strand
Mutations occur when there are changes in the DNA sequence

Description

This quiz covers the basics of genetics, including heredity, variation, genotype, phenotype, alleles, and chromosomes. Learn about the structure and function of chromosomes and how traits are passed down from parents to offspring.