Genetics and Cell Division Flashcards

Flashcards about genetics, DNA, cell division, and inheritance. These flashcards are intended to assist in exam preparation.

What is the function of DNA?

Stores and transmits genetic information and functions in the same way in all living things.

What are the three components of a nucleotide?

Phosphate, sugar (deoxyribose), and a base (adenine, thymine, guanine, or cytosine).

What are the base-pairing rules in DNA?

Adenine (A) pairs with Thymine (T), and Guanine (G) pairs with Cytosine (C).

What forms the backbone of a DNA molecule?

The alternating sugar and phosphate groups.

What holds information and makes up the genetic code?

The order of nucleotides.

What is a gene?

A unique sequence of nucleotides that codes for a functional protein or RNA molecule.

What controls cellular processes in all living things?

Proteins.

What does phenotype refer to?

Traits/appearance.

What are genes?

Segments of DNA that direct the assembly of proteins in a cell.

Describe the structure of DNA.

A helical, double-stranded molecule.

What are chromosomes?

Structures formed when DNA coils around proteins in the nucleus of cells.

When are chromosomes observed?

During cell division.

What is the purpose of mitosis?

Growth, repair, or reproduction in unicellular organisms.

What is the purpose of meiosis?

Production of gametes containing half the amount of DNA.

What type of cells does mitosis produce?

Genetically identical daughter cells.

What type of cells does meiosis produce?

Unique sex cells called gametes.

Where does meiosis occur?

Gonads (testes or ovaries).

What does mitosis do to the genetic content?

Maintains the genetic content (diploid 2N).

What does meiosis do to the genetic content?

Halves the genetic content (from diploid 2N to haploid N).

What does fertilization do to the diploid number?

Restores the diploid number.

What is a locus?

Genes coding for the same trait located at a particular position on a chromosome.

What are alleles?

Different versions of a gene.

What structure do homologous chromosomes have in common?

They have the same structure.

What are the stages of Meiosis?

Interphase, Meiosis I, Meiosis II

During what phase of Mitosis do centromeres split?

Anaphase

What can result in mutations?

Errors in DNA replication, errors in cell division, damage by physical or chemical factors, viruses.

What are types of mutations?

Point mutation, frame shift, parts or whole chromosome involved.

Describe point mutations.

Change in a single base pair; may or may not change the protein.

Describe frame shift mutations.

Deletion or insertion of a base pair that shifts the reading frame.

Describe inversion mutations.

The reading frame does not shift, but the affected number of codons depends on the size of the inverted region.

What factors increase the rate of mutation?

Ionizing radiation, excessive temperature, mutagenic chemicals, viruses.

How do mutagenic chemicals lead to mutation?

Mimics or binds to nucleotides, interrupting base-pairing.

How do viruses lead to mutations?

Viral DNA is incorporated into the host DNA, introducing changes to the chromosome.

What mutations have a greater potential to affect more cells?

Mutations occurring in gonads.