B1 Genomes And Characteristics Flashcards
What are chromosomes?
Really long molecules of DNA
What is the genome?
The entire genetic material of an organism.
Where is genetic material stored in plant and animal cells and how is it arranged?
Stored in the nucleus, arranged into chromosomes.
How many pairs of chromosomes do humans have?
23 pairs (46 chromosomes in total)
What is a chromosome?
A very long molecule of DNA that’s coiled up.
DNA is a polymer. What is a polymer?
A molecule that’s made up of smaller, repeating units called monomers.
What are DNA monomers called?
Nucleotides
How many strands of nucleotides does each DNA molecule contain and what is its structure?
Two strands of nucleotides, which coil together to form a double helix.
What are genes?
The instructions in genomes.
A short length of DNA on a chromosome.
What does each gene code for?
A particular sequence of amino acids, which are put together to make a specific protein.
What is the process of making a big molecule (eg a protein) from lots of smaller proteins called?
Polymerisation.
What do proteins control?
The development of different characteristics (eg dimples) and how an organism functions.
What is an allele?
A different version of the same gene.
What is the different version of the same gene called?
Alleles or genetic variants
What is the combination of alleles an organism has for each gene called?
It’s genotype
What makes a organisms genome unique?
It’s genotype.
What is phenotype?
The characteristics the organism displays
What do interactions with the environment affect?
They can modify the phenotype.
Give an example of a how environment can affect the phenotype of a plant.
If a plant is grown in the sun it could grow green and luscious.
The same plant grown in the darkness would grow tall and spindly and its leaves would turn yellow.
How are variations in phenotype determined?
Give a example of how height is determined.
By a mixture of genetic and environmental factors.
Example the max height a plant or animal can grow is determined by its genes, but whether it actually grows that tall depends on its environment.
What is an organisms genome?
The entire genetic material of an organism (1 mark)
What is an organisms
a) genotype
b) phenotype
a) an organisms genotype is the combination of alleles it has for each gene. (1 mark)
b) an organism’s phenotype is the characteristics it displays (1 mark)
