Genes Flashcards
define natural selection
the process where characteristics are passed on to ensure the survival of the species.
what is the evolution theory by Charles Darwin?
it states that through producing offspring’s that show variations enabling them to survive, the adapting genes are them passed on through future generations
what does biodiversity mean and give 2 ways it be measured?
Biodiversity is the variety of living things within an ecosystem. This can be measured by considering:
- the number of different species: high diversity= high number of species
-the differences between individuals of the same species: high diversity= wide range of differences
what are Gene Banks?
Gene Banks are a strategy being used to persevere the genetic material of a plant or animal that is endangered. Other strategies include are: captive breeding, creating protected areas and habitats.
how many chromosomes do humans have?
23 pairs
fill in the blanks:
XX chromosomes are for _____
and XY chromosomes are for _____
female
male
how is down syndrome caused?
when the genetic material is made of three chromosomes instead of two (trisomy).
how are twins identical?
They are formed when a fertilised egg divides into two halves within the first twelve days of growth. Each half continues to develop into an embryo. They will have the same genetic information.
how are twins non-identical?
They are formed from two fertilised eggs and are no more identical than any other siblings from the same parents.
how are twins conjoined?
They are where an egg only partially splits. Each part continues to develop but there will be come shared organs from the twins.
what are inherited characteristics?
Genes are passed from one generation to the next and control the characteristics we inherit.
