Year 10 Biology - Genetics

Flashcards for Year 10 Biology - Genetics (DNA to mutations)

What is DNA?

A molecule found in the nucleus of cells that determines many of our characteristics and gives instructions to cells to make proteins.

What is the shape of DNA referred to as?

A twisted ladder or zipper shape

Who discovered the structure of DNA?

James Watson & Francis Crick, based on Rosalind Franklin's x-ray images.

What are the three components of a nucleotide?

1 sugar, 1 phosphate, and 1 base (containing N)

What type of bonds attract the bases to each other in DNA?

Hydrogen bonds

What are chromosomes?

Long threads of DNA.

What is a gene?

A section of a chromosome that gives instructions for a particular feature.

What is an allele?

A different form of a gene.

what are the four different bases in DNA?

adenine (A), cytosine (C), guanine (G), and thymine (T)

What is the complementary base pairing rule in DNA?

Adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G).

What is Mitosis used for?

Growth, wound and tissue repair, asexual reproduction, tissue regeneration

What happens during mitosis?

The cell and its contents, including chromosomes, are divided equally to create an identical diploid copy.

What must occur before a cell can divide again via mitosis?

The DNA must replicate to become 2 identical chromatids.

During the cell cycle, in which phase does the cell spend most of its time?

Interphase.

What are the main stages of mitosis (PMAT)?

Prophase, Metaphase, Anaphase, and Telophase.

What is a karyotype?

The chromosomes are arranged in pairs and organized to show autosomes and sex chromosomes.

Which chromosomes do NOT determine the sex of the offspring?

Autosomes (pairs 1-22)

Which chromosomes determine the sex of the offspring?

XX = female, XY = male

What is translation?

The process when the information in the DNA is used to produce a protein.

How is the copy of the DNA made?

A copy of the DNA is made (transcription) and this copy moves to the ribosomes where the protein is made (translation).

What codes for a particular amino acid?

A triplet or codon

What is the role of a gene?

Codes information for a particular function and the production of a protein such as structural proteins or enzymes.

What is an allele?

A different version of a gene.

What are the building blocks of all proteins called?

Amino acids

What is the difference in the types of sugar in DNA and RNA?

DNA: deoxyribose, RNA: ribose

What is the difference in strands between DNA and RNA?

DNA: 2 strands, RNA: one strand

What is the difference in bases between DNA and RNA?

DNA: thymine (T), RNA: uracil (U)

What reads the DNA in groups of 3 (called triplets)?

The ribosome

What is the role of messenger RNA (mRNA)?

mRNA is a copy of the genetic information transcribed from DNA, brought to the ribosome, and translated into protein.

What happens during transcription?

Transcription makes mRNA to carry the code for proteins out of the nucleus to the ribosomes.

What happens during translation?

Translation assures that the right amino acids are joined together to form the correct protein.

What is the central dogma of molecular biology?

DNA to mRNA to Protein

Which enzyme copies the DNA template to make mRNA?

RNA polymerase

What are mutations?

Mistakes in the DNA sequence.

What is the result of all new alleles originating by mutation?

Introduces genetic variation in an individual and to a population

What is a mutagen?

Anything that causes a mutation.

What is the difference between gametic and somatic mutations?

Gametic mutations occur in the gametes and are inherited, while somatic mutations occur in the body cells and are not inherited.

What are the potential effects of a mutation on an organism?

Lethal, harmful, silent (neutral), or beneficial.

What are point mutations?

Mutations involving a single nucleotide

What is a missense mutation?

Different protein is produced

What is a nonsense mutation?

Protein formation stops too early

What is an example of frameshift mutations?

TAC GGG AGC CAC GTC ACT CAT AAA (original base sequence) TAC GGG AGC TCA CGT CAC TCA TAA A.. (new base sequence)

What are some types of chromosome mutations?

Inversion, translocation, duplication, and deletion.

What are some examples of mutagens?

radiation (e.g. UV rays, X-rays), viruses, microorganisms, environmental poisons and irritants, alcohol and diet