Genetics Inheritance Review Flashcards
(26 cards)
What is DNA and what are its main components
DNA is a molecule that carries genetic information. Its structure consists of a double helix formed by nucleotides, which include a phosphate group, a sugar, and a nitrogenous base
What is the function of DNA and where is it located in the cell?
The function of DNA is to store and transmit genetic information. It is located in the nucleus of eukaryotic cells and in the cytoplasm of prokaryotic cells.
If the percentage of adenine (A) in a DNA sample is 30%, what is the percentage of thymine (T)?
The percentage of thymine (T) is also 30% due to complementary base pairing.
Given the DNA sequence ATCC, what is the complementary strand
The complementary strand is TAGG.
Define a chromosome
A chromosome is a long strand of DNA that contains many genes.
How many chromosomes do humans have in most body cells and in gametes
Humans have 46 chromosomes (23 pairs) in most body cells and 23 chromosomes in gametes
What is a gene?
A gene is a segment of DNA that codes for a specific trait or protein.
What are homologous chromosomes?
Homologous chromosomes are pairs of chromosomes, one from each biological parent, that have the same genes at the same loci.
Distinguish between autosomes and sex chromosomes
Autosomes are non-sex chromosomes, while sex chromosomes (X and Y) determine biological sex.
What is DNA replication and when does it occur?
DNA replication is the process of copying DNA before cell division.
Outline the steps of DNA replication
The steps of DNA replication include unwinding the double helix, pairing of complementary bases, and formation of new strands.
What can result from errors in DNA replication?
Errors in DNA replication can lead to mutations, which may have biological consequences.
Define a mutation.
A mutation is a change in the DNA sequence of a gene or chromosome.
What are the two types of mutations?
Gene mutations affect individual genes, while chromosomal mutations affect the structure or number of chromosomes.
How can mutations be classified based on their effects?
Mutations can be beneficial, harmful, or neutral, depending on their effect on the organism.
What is the significance of mutations in somatic cells versus gametes?
Mutations in somatic cells are not inherited, while mutations in gametes can be passed to offspring.
Give examples of genetic conditions caused by mutations
Examples include cystic fibrosis, sickle cell anemia, and Down syndrome.
What is mitosis?
Mitosis is the process resulting in two genetically identical daughter cells.
What are the main stages of mitosis?
The main stages of mitosis are prophase, metaphase, anaphase, and telophase.
What is meiosis and what does it produce?
Meiosis is a type of cell division that produces gametes (sperm and egg cells) with half the number of chromosomes.
How does meiosis contribute to genetic variation?
Meiosis results in genetic variation through processes like crossing over and independent assortment.
Compare meiosis and mitosis in terms of purpose and genetic outcomes
Mitosis produces two identical cells for growth and repair, while meiosis produces four non-identical gametes for sexual reproduction.
Define gene, allele, genotype, and phenotype
A gene is a segment of DNA coding for traits; an allele is a variant of a gene; a genotype is the genetic makeup; and a phenotype is the observable traits.
What is a Punnett square used for?
A Punnett square is used to predict the possible genotypes and phenotypes of offspring from a genetic cross.
