Inheritance Flashcards
What is a genome
The entire DNA of a molecule
What is a gene and where are they located
A section of a molecule that codes for a specific protein (amino acids)
In chromosomes
Where are chromosomes located
In the nucleus
What is DNA
two strands coiled to form a double helix
What are the 4 bases and their pairs
adenine (A) with thymine (T)
cytosine (C) with guanine (G)
How many strands is RNA
1
What is the difference between RNA and DNAs bases
RNA contains uracil (U) instead of thymine (T)
How does protein synthesis work
https://igcse-biology-2017.blogspot.com/2017/06/318b-describe-stages-of-protein.html
- 3.34 understand that mutation is a rare, random change in genetic material that can be inherited
you already know that!!!
- 3.35B understand how a change in DNA can affect the phenotype by altering the sequence of amino acids in a protein
- 3.36B understand how most genetic mutations have no effect on the phenotype, some have a small effect and rarely do they have a significant effect
How can mutation likelyhood be increased
exposure to ionising radiation (for example, gamma rays, x-rays and ultraviolet rays) and some chemical mutagens (for example, chemicals in tobacco)
don’t need to know all example
- 3.31 understand how random fertilisation produces genetic variation of offspring
As random genotypes are taken from each parent
how many diploid and haploid chromosomes are their
Diploid = 46
Haploid=23
What are the two causes of genetic variation
- environmental
- genetic
(- a mix of both)
What other form do genes exist in
Alleles
What does dominant mean when referring to an allele
An allele that will always express itself in the phenotype (only requires one allele)
What does recessive mean when referring to an allele
An allele that will only express itself in the phenotype if partnered with another recessive allele ( requires two alleles)
What does homozygous mean when referring to an allele
When an individual has two identical Alleles of a Gene (two of dominant or recessive)
What does heterozygous mean when referring to an allele
When an individual has two different Alleles of a Gene
Phenotype definition
Th physical manifestation of a genotype
Genotype definition
The genetic makeup of an individual regarding alleles
- 3.23 describe patterns of monohybrid inheritance using a genetic diagram
- 3.25 predict probabilities of outcomes from monohybrid crosses
https://www.savemyexams.com/igcse/biology/edexcel/19/revision-notes/3-reproduction-and-inheritance/inheritance/monohybrid-inheritance-genetic-diagrams/
What shape is a female and what shape is a man in a pedigree diagram
- 3.24 understand how to interpret family pedigrees
Man - square
Woman - circle
https://igcse-biology-2017.blogspot.com/2017/06/324-understand-how-to-interpret-family.html#google_vignette
How many sets of chromosomes is the sex of a person controlled by
+
what chromosomes are for a male and for a woman
1 set
Man = XY
Woman = XX
Codominance meaning
both alleles within a genotype are expressed in the phenotype of an individual (both are dominant)
If heterozygous (2 different alleles) then a mix of the two (a third option) is shown in the phenotype
E.g:
RR = Red plant
WW = White plant
RW = Pink plant
What is Darwins theory of evolution
The organisms that have mutations which give them an advantage to survive outlive the other organisms and therefore reproduce more, passing on their beneficial mutation over many generations until most organisms have it.
How can resistance to antibiotics increase in bacterial populations
As bacteria develop MUTATIONS? which then are passed down generations when they survive longer and reproduce
