Foundation: B6 - Inheritance Flashcards
What type of cells does meiosis produce?
Gametes
How many chromosomes are in a human sex cell?
23
How many chromosomes are in a human body cell?
46
What is sexual reproduction?
Reproduction in which gametes from two parents fuse, eg. egg and sperm
What is asexual reproduction?
Reproduction that involves only one parent.
What type of offspring are produced in asexual reproduction?
Genetically identical
What type of offspring are produced in sexual reproduction?
Genetically unique
Outline the stages of meiosis.
- Copes of genetic information are made
- The cell divides twice to form four gametes, each with a single set of chromsomes
- All of the gametes are genetically different from each other
What is the structure of DNA?
A polymer that forms a double helix
What is a gene?
A small section of DNA on a chromosome.
What is the role of a gene?
It codes for a sequence of amino acids to make a specific protein
What is a genome?
The entire genetic material of an organism
Why is understanding the human genome important?
It can help idenitfy genes linked to certain types of diseases
It can help to understand and treat inherited diseases
It is used to trace human migration pattersn
What is a gamete?
A sex cell
What is an allele?
One version of a gene
What is a dominant allele?
One allele is needed for the characteristic to be present
What is a recessive allele?
Two copes of the alleles are needed for the characteristic to be present
Define genotype
The combination of alleles an individual has
Define phenotype
The characteristics an individual has
What does homozygous mean?
Two of the same alleles
What does heterozygous mean?
Two different alleles
What is polydactyly?
An inherited disorder that causes extra fingers or toes
What type of allele causes polydactyly?
A dominant allele
What is cystic fibrosis?
An inherited disorders that causes problems with the lungs
What type of allele causes cystic fibrosis?
Two recessive alleles
What sex chromosomes do females have?
XX
What sex chromosomes do males have?
XY
What factors can affect the characteristics an individual has?
Genetic, environmental or both
What is variation?
Differences between individuals
What is the cause of all variation?
Random mutations of DNA
What is a species?
Organisms that can reproduce to produce fertile offspring are in the same species.
What process causes changes to a population over time?
Natural selection
What is selective breeding?
Humans select which individuals should breed based on their traits, to produce offspring with similar traits.
What types of characteristics have been chosen for through selective breeding?
Disease resistance in crops
Animals that produce more milk or meat
Domestic dogs with a gentle nature
Large or unusual flowers
What are some problems with selective breeding?
It can lead to inbreeding which causes some breed to be prone to disease or inherited defects
What is genetic engineering?
Genes from one organism are inserted into the genome of another to give a desired characteristic
What have plants been genetically engineered for?
To produce bigger and better fruits
To be resistant to diseases
What have bacterial cells been genetically engineered for?
To produce useful substances like insulin for people with type 1 diabetes
What is the eveidence for evolution?
The fossil record
Antibiotic resistant bacteria
Genetic evidence
Why are there gaps in the fossil record?
It is difficult for soft tissue to be fossilised
What is extinction?
When there are no remaining individuals of a species still alive.
How can the development of antibiotic resistance be reduced?
Not over prescribing antibiotics
Completing prescribed courses of antibiotics
Reducing the use of antibiotics in farm animals
What scientist developed the binomial classification system?
Carl Linnaeus
How are organisms classified?
Kingdom, phylum, class, order, family, genus, species
How are organisms named with the binomial system?
Genus and species
What are the three domains?
Archaea, Bacteria, Eukaryota
