Inheritance, Variation And Evolution(B)(p1/2) Flashcards
What Is DNA?
Deoxyribonucleic acid. It is a polymer and has a double helix structure
What are chromosomes ?
Tight coils that contain DNA. Each human cell has 46 chromosomes (2 of 23 human pairs)
What are the 23rd pairs referred to?
Sex chromosomes
What is a man and women chromosomes?
Male: xy
Female: xx
Why are chromosomes drawn within a circle?
Due to This being before cell division (mitosis, meiosis)
What are genes?
Small sections of DNA that codes for a protien.
(It codes sequences of amino acid. That can be combined to form many proteins) such a RDB from hemoglobin
What are genomes?
Entire sets of genetic material in an organism.
-they are usually inherited from our parents
How can someone’s genome help with medical treatment?(3)
They can use genomes to identify inherited diseases.
Or identify the increased risk of getting one
(Help identify migration of ancestors??!)
What is an allele?
Different versions of a gene
What is the difference between a homozygous and a heterozygous?
Homozygous has the same allele
Whilst heterozygous has 2 different alleles
What happens when there’s on dominant and recessive allele?
The dominant allele is exprés
What happens when there’s 2 recessive alleles
Recessive allele is expressed
What are genotypes?
Collection of alleles we have?
What are phenotypes?
Characteristics you get from genotype
What is sexual reproduction
Fusion of male and female gametes via fertilization. Which are genetically different to parent
What are gamete’s?
They have half genetic material of normal human cell. Considers haploid cells
(Sperm, egg, pollen)
What is asexual reproduction?
When there is no mixing of genetic material to produce genetically identical offsprings
Eukaryotic (animal plant) via mitosis
Prokaryotic (bacteria) via binary fusion
what is meiosis?
-replicates DNA to make all x
-lines up in centre cell
-chromosomes pull apart(randomly distributed)
-2 arms pulled apart to opposite sides of cell
0divides further mad=ke 4 genetically identical cells called gametes
what is variation?
where different individuals have different phenotypes (characteristics) different proteins which are affected by genes and environment
what are mutations?
change DNA code-dont affect proteins-so don’t change phenotype(bat can, usually is very bad cases, but sometimes good)
what is natural selection?
fittest individuals are select to survive
what is evolution?
natural selection of genetic changes that rise to phenotypes best suited for environment/
inherited characteristics in population over multiple generations, could lead to change whole species
[shown in antibiotic resistance and fossils]
what fossil evidence can be used for evolution?
- gradual replacement minerals
-rock like substance
-casts(clay is left with gap, that was same size as organism)
-preservation: no decay, so completely stays intact
what is classification system?
domain-kingdom-phylum-class-order-family-genus-species
what are 3 domains?
archaea, bacteria, eukayrota
