Year 10 Biology Flashcards
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What are the building blocks of DNA
A modecule of DNA is made up of millions of tiny subunits called Nucleotides.(monomer) mono=1
What are the components of nucleotide?
Each nucleotide consist of: 1. Phosphate group. 2. Pentose sugar 3. Nitrogenous base.
What components form the DNA backbone?
The phosphate and sugar form the backbone of the DNA molecule.
What component form the rungs?
The nitrogenous bases form the “rungs”
What are the four types of nitrogenous bases?
Adenine (A),Thymine(T),Cytosine(C),Guanine(G)
What is complementary base pairing?
Complementary base pairing is each base will only bond with one other specific base. A-T C-G
Why does DNA have a double Helix?
These rules and components allow DNA to form a double Helix.
Where is DNA located in the cell?
In the nucleus holds genetic information (DNA)
How is DNA organised in the nucleus?
Organised into units called genes, genes are found on chromosomes. DNA-Genes-Chromosomes
What is a Gene?
A segment of DNA that codes for particular protein: eg eye colour.
How many pairs of chromosomes do humans have?
23 pairs- 46 in total
What does diploid mean?
A paired set of chromosomes in somatic cells.
What is a somatic cell?
Cells of the body except sex cells.
What are gametes?
Reproduction or sex cells (sperm/ovar)
What does haploid mean?
The possession of one copy of each chromosomes in a cell (46/2 =23)
What sex chromosomes do males and females have?
Females- XX
Males-XY
What is a Autosome?
Any chromosomes not involved in sex determination.
What is a sex chromosome?
The chromosomes that determine an individuals sex.
What is a Karyotype?
A karyotype is the visualisation of an individuals of collection of chromosomes.
What is the purpose of the Karyotype?
To look for abnormal numbers or structures of chromosomes.
What is a homologous?
The same size, shape, and carry the same genes.
Where do you get the matching pairs?
One of the pair from you Dad and one of the pair from your Mum.
What is an Allele?
The different versions/forms of a gene are called Alleles eg- brown eyes/ green eyes
What is the difference between a Gene and Allele?
Gene specifies trait, Allele specifies form gene takes.
What are dominant Alleles?
These Alleles will always be expressed when they’re present.
What are recessive Alleles?
These Alleles are expressed only when there are two recessive Alleles.
What is a Genotype?
The Alleles that a person has example- Bb
What is a Phenotype?
The trait that is seen example- brown eyes
What does Homozygous mean?
The same BB or bb
What does Heterozygous mean?
Different Bb
What is a genetic cross?
It measures the probability of all outcomes for a specific genetic cross.
What is a punnettt square?
It is a tool we use to do a cross.
How to complete a punnett square?
1.Designate characters to represent alleles (e.g. A=dark red; a= light red)
2. Write the genotype and phenotype of the parents (e.g dark red cross: Aa x Aa)
3. Use a grid to work out gamete combinations (see steps shown below)
4. Write the genotype and phenotype ratios pf offspring ( 3 dark red : 1 light red)
what is a pedigree chart?
It is a chart of the genetic history of family over several generations.
How to determine if the pedigree chart shows an autosomal or X-linked disease?
If most of the males in the pedigree are affected the disorder in X- linked.
If its a 50/50 ratiop between men and women the disorder is autosomal.
How to determine whether the disorder or traits is dominant or recessive?
If the disorder is dominant, one of the parents must have the disorder.
If the disorder is recessive, neither parent has to have the disorder because they can be heterozygous.
Left to right are oldest to youngest
Roman numerals are used for numbering generations.
What are protein?
They are larger very complex molecules, necessary for EVERY living organism. “Genetic traits rely on proteins.”
What are the building blocks of proteins?
Amino Acids
How are proteins unique?
Each protein has a specific function and specific shape enable it to perform that function.
What does DNA stand for?
Deoxyribose Nuclic Acid
How does DNA make for proteins?
Contain instructions on how to build proteins used in the body.
Where is the protein made?
In Ribosome.
Why do we need to convert DNA?
DNA molecules are to large.
What is the difference between DNA an RNA?
DNA. RNA
sugar: deoxyribose Ribose
size: Double Single
base: A,T,G,G A,U,C,G
What is a transcription?
The process by which DNA is “read” to produce a strand of mRNA
What is a translation?
The process by which mRNA is ‘read’ to produce a strand protein chain.
What tRNA stand for?
Another type of RNA is involved in this stage transfer RNA (tRNA)
What does tRNA carry?
individual ,anino, acids
What does degenerate mean?
More than one codon for most amino acids. AUA, AUC or AUU= isoleucine
