Year 10 Biology Flashcards
What are the building blocks of DNA?
DNA is made up of millions of monomers called nucleotides.
What are the components of a nucleotide?
Phosphate group, Pentose sugar, Nitrogenous base
What structure is DNA in?
DNA is arranged in a double helix.
What components make up the backbone?
The phosphate and sugar form the backbone.
What components make up the DNA ladder rungs?
The bases form the rungs.
How many Nitrogenous bases are there?
There are four types of Nitrogenous bases ( Adenine, Thymine, Cytosine, Guanine ).
What is complementary base pairing?
Complementary base pairing means each base will only bond with one specific base ( A - T, C - G )
What is a gene?
Genes are a section of a chromosome, that code for a specific protein.
What is the significance of proteins?
Proteins give us our traits.
Where is DNA found?
DNA is found in the nucleus.
How is genetic information organised?
Genetic information is organised into units called genes. Genes are found in chromosomes.
How many pairs of chromosomes do humans have and what is the total number?
Human body cells have 23 pairs of chromosomes. This gives us a diploid number of 46.
What does diploid mean?
Diploid is a pair/set of chromosomes in somatic cells.
What is a somatic cell?
A somatic cell is a cell in the body except sex cells (eg. nose and cheek cells).
What are gametes?
Gametes is another word for reproductive or sex cells (sperm and egg).
What does haploid mean?
Haploid refers to the possession of one copy of each chromosome per cell.
What is an autosome?
An autosome is any chromosome not involved with sex determination.
What is a sex chromosome?
A sex chromosome is the only chromosome that determines an individuals sex ( females - XX, Male - XY
What is a Karyotype?
A karyotype is an individuals collection of chromosomes.
What is the purpose of a karyotype?
The karyotype is used to look for abnormal numbers or structures of chromosomes.
What is a homologous chromosome?
Homologous chromosomes are the same size, shape and carry the same genes.
What is down syndrome?
Down syndrome is trisomy 21, meaning they have three chromosomes in chromosome 21.
What is turner syndrome?
Turner syndrome is monosomy x meaning they only have one x chromosome.
What is Klinefelter syndrome?
Klinefelter syndrome is when you have an extra x chromosome, xxy. (still considered a male).
What is an allele?
An allele is different forms of the same gene. eg hair colour, eye colour.
What are dominant alleles?
Dominant alleles are expressed when they are present.
What are recessive alleles?
Recessive alleles are expressed only when there are two recessive alleles.
What is a genotype?
A genotype is the alleles that a person has.
What is a phenotype?
A phenotype are the traits that are seen.
What does homozygous mean?
Homozygous is two of the same allele.
What does heterozygous mean?
Heterozygous is one of each type of allele.
What is a genetic cross?
A genetic cross is a mechanism to measure the probability of all outcomes for a genetics cross.
What is a punnett square?
A punnett square is the tool we use to do a genetic cross.
How do you represent a punnett square?
- Designate characters to represent alleles.
- Write the genotype of the parents.
- Use a grid to work out gamete combinations.
- Write the genotype ratios of offspring.
What are the possible percentages of a genotype?
The possible percentages are:
- 4/4, 100%
- 1/4, 25%
- 2/4, 50%
- 3/4, 75%
What is a pedigree?
A pedigree is a chart of the genetic history of a family over several generations.
How is the number of generations denoted?
To denote the numbers of generations in a pedigree chart, we use roman numerals.
How to determine if the pedigree shows an autosome?
When there is a 50/50 ratio between men and women, the disorder is autosomal.
How to determine if a pedigree chart shows a x-linked disease?
If most of the males in a pedigree are affected the disease is x linked.
How to determine if a disorder is dominant?
If a disorder is dominant, one of the parents must have the disorder.
How to determine if a disorder is recessive?
If a disorder is recessive, neither parents has to have the disorder because they can be heterozygous.
What are proteins?
Proteins are very large complex molecules necessary for every living organism.
What are proteins made up of?
Proteins are made up of amino acids.
How are proteins unique?
Each protein has a specific function and a specific shape to enable it to perform that function.
How does DNA code for amino acids?
Each 3 bases of DNA codes for a specific amino acid.
Where are proteins created?
Proteins are created in Ribosomes.
Why do we need to convert DNA?
We need to convert DNA because it is too large to leave the nucleus.
What is DNA converted to?
DNA is converted to messenger RNA (mRNA).
What does RNA stand for?
RNA stands for ribonucleic acid.
Whats the process called to get DNA to mRNA?
The process to get DNA to mRNA is called transcription.
What is the enzyme involved in transcription?
The enzyme involved in transcription is RNA polymerase.
What do RNA polymerase do?
RNA polymerase reads the DNA and builds the mRNA.
