10.5 Types of Variation Flashcards
Definition of interspecific variation
Variation between members of different species
What is an example of interspecific variation
Mice have 4 legs, dogs have 2 legs
What is intraspecifc variation
Difference between organisms within a species
What is an example of intraspecifc variation
Varying height
What are the factors that cause genetic variation?
-an organism genetic material, differences in genetic material inherited from parents
-the environment an organism lives in
What are the causes of genetic variation?
Alleles, mutations, meiosis, sexual reproduction, change
How do alleles cause genetic variation?
Genes have different alleles, different alleles produce different effects. Individuals within a species may inherit different alleles of a gene
Eg. Human blood type has 3 different alleles (A, B, O) and depending on the parental combination of these alleles four different blood groups can be produced (A, B, AB, O)
How do mutations cause genetic variation?
Changes got a DNA base sequence, change in proteins that are coded for
How does meiosis cause genetic variation?
Each gamete produced relieves half the genetic material of a parent cell. Genetic material inherited from two parents is ‘mixed up’ by independent assortment and crossing over
How do sexual reproduction cause genetic variation?
The offspring produced from two individuals inherits genes (alleles) from each of the parents. Each individual produced therefore differed from the parents
How does chance cause genetic variation?
During sexual reproduction it is by chance as two which two combine (random fertilisation), the individuals produced are different from their siblings and contains a unique combination of genetic material
Is there greater change of variation in sexual or asexual reproduction?
Sexual, as asexual reproduction results in clones that are genetically identically to their parents
What are environmental causes of variation?
-Organisms with greater access to sun will generally grow larger
-Presence or absence of scars on the body, occur as a result of accident or disease
What organism are more likely to have variation due to environment causes and why?
Environmental cause of variation is greater in plants than animals due to their lack of mobility
In most cases what is variation caused by?
A combination of both environmental and genetic factors
What is an example of variation caused by a combination of genetic and environmental factors?
-If your parents are tall, you most likely inherit the gendered to be able to grow tall, but if you eat a poor diet or suffer from disease you only grow to below average height
-Skin colour, determined by how much melanin you have, it is determined at birth by your genetics, but if you expose your skin to sunlight you produce more melanin to protect your skin from harmful UV, and your skin will turn darker
