CELL DIVERSITY IN ANIMALS Flashcards
What is the ratio of surface area to volume for single-celled and multi-cellular organisms
Single-celled organisms are small and have a large surface area to volume ratio while multicellular organisms are larger and have a smaller surface area to volume ratio
What’s the name of the undifferentiated cell that all multicellular eukaryotic organisms start as
zygote
What is the genetic material with an individual
genome
What type of cell is a genome
a stem cell
when does an embryo form
after several mitotic divisions
state two types of specialised cells in animals
erythrocytes and neutrophils
what are erythrocytes
they are specialised cells that carry oxygen from the lungs to respiring cells
what do neutrophils do
they ingest invading pathogens
State a similarity between erythrocytes and neutrophils
They both derive from stem cells in the bone marrow
how are erythrocytes adapted to their function
they are very small (7.5 nanometers in diameter) so have a large SA/V (surface area to volume) ratio. so oxygen can diffuse across their membranes and easily reach all regions inside the cell. Erythrocytes also have a biconcave shape that increases their SA/V ratio
how are erythrocytes adapted to their function
they reflexible. A well developed cytoskeleton allows the erythrocytes to change shape so that they can twist and turn as they travel through very narrow capillaries
how are erythrocytes adapted to their function
They have free space without organelles and very little cytoplasm allowing haemoglobin molecules to be housed in the space.
Which organelles aren’t in erythrocytes
Nucleus, mitochondria, endoplasmic reticulum and they have very little cytoplasm
What percentage of white blood cells does neutrophils make up in the body.
50%
neutrophils are bigger than erythrocytes. true or false?
True. It is about twice the size as neutrophils have a multilobed nucleus
