4.6 Flashcards
what does meiosis do to the number of chromosomes in gametes
halves them
what does fertalisation do to the number of chromosomes
restores the full number of chromosomes
which cells divide by meiosis to form gametes
cells in reproductive organs
what happens to the genetic information when a cell divides by meiosis to form gametes
copies of the genetic information is made
what happens to the 4 gametes from the cell division
join at fertilisation to restore the normal number of chromosomes
the new cell then divides by mitosis
increasing the number of cells
what happens to the cells as the embryo develop
they differentiate
who developed the traditional classification system
and when
Carl Linnaeus
1700s
what are the different classifications in the Linnaeus system
kingdom, phylum, class, order, family, genus and species
why is it important that blood glucose levels are controlled
glucose is needed by every cell to release energy by respiration
essential the concentration of glucose in the blood is controlled and stays as constant as possible
how is a person with type 1 diabetes different from a person without diabetes
person with type 1 diabetes pancreas cannot produce the hormone insulin
so their blood glucose levels can rise to dangerous levels, especially after a meal
what is classification
process of putting living organisms into groups
who developed the Linnean system
and when
Carl Linneas
1700s
List the 7 levels of the Linnean system
Kingdom Phyla Class Order Family Genus Species
how is the kingdom taxa different to the species taxa
kingdom is the top level and has the:
fewest groups
most individuals
and greatest variation
how is the kingdom taxa different to the species taxa
the kingdom is the top level and has the fewest groups, most individuals and greatest variation
species is the lowest level and has the most groups with the fewest individuals who are most similar to each other
how are things classified into groups in the linnean system
depending on their structure and characteristics
how are organisms names
by the binomial system of genus and species
e.g homo sapiens
impact on biology from classification systems
aids communication and evolutionary relationships
how did the understanding of biochemical process progress
evidence of internal structures became more developed due to improvements in microscopes
who developed the three-domain system
and when
Carl Woese
1900s
how are organisms divided in the three-domain system
Archeae
Bacteria
Eukaryota
which organisms are placed into Archaea
primitive bacteria usually living in extreme environments
which organisms are placed into Bacteria
true bacteria
which organisms are placed into Eukaryota
all complex cellular organisms
which includes: animals, plants, protists and fungi
what are evolutionary trees used for
what data do they use
method used by scientists to show how they believe organisms are related
use current classification data for living organisms and fossil data for extinct organisms
how can you tell which organisms are most commonly related using an evolutionary tree
which have the most common ancestor
how many times do cells divide to form gametes
cell divides twice to form 4 gametes, each with a single set of chromosomes
are all gametes genetically identical to each other
no they are all different
