Multicellular Organisms Flashcards
describe the stages of mitosis
chromosomes condense.
the membrane around the nucleus breaks down.
the chromosomes line up along the equator of the cell.
spindle fibres form and pull the chromosomes apart to opposite ends of the cell.
membranes form around each of the sets of chromosomes; the nucleus has divided.
the cytoplasm and cell membrane divide, forming two new daughter cells.
what are stem cells
unspecialised cells which have the potential to form specialised cells
what are the functions of neurons
to carry electrical signals through the body
what does it mean when a cell is specialised
it carries out a specific job in the body
what is a tissue
a group of similar cells that work together to carry out a particular function
what is an organ
a group of different tissues that work together to perform a certain function
what is a system
a group of organs working together to perform a certain function
what are gametes
sex cells
are gametes haploid or diploid
haploid
define diploid
a cell which contains the full number of chromosomes as a body cell
what is the fusion of gametes known as
fertilisation
what is a zygote
a fertilised egg
what is the function of the ovaries
they produce the egg cells
where are sperm made
in the testes
what is the female reproductive organ in plants
the carpel
what is the stamen made up of
the anther and the filament
what is the role of the anther
contains pollen grains which produce sperm
what is the role of the stigma
where pollen grains attach to
what is meant by continuous variation
where the values vary within a range
what are some examples of continuous variation
height, shoe size, weight, hand span, finger length
what is meant by the term discrete variation
the values fall into distinct categories
some examples of discrete variation are….
blood type, hair colour, eye colour, widows peak, hitchhikers thumb, tongue rolling
what are alleles
different versions of genes, represented by letters e.g Aa, Bb, Gg
what is meant by phenotype
the characteristics displayed by an organism
