biology Flashcards
animal and plant eukarytic cells contiain
cell membrane
cytoplasm
nucleus
mitochondrion
cell wall (plant only)
chloroplast (plant only)
vacuole (plant only)
prokaryotic cells contain
cell membrane
cytoplasm
cell wall
chromosomal DNA/no ‘true’ nucleus
plasmid DNA
levels of organisation
cells to tissues to organs to organ systems
interphase
cell grows and DNA is copied
mitosis
division leading to two daughter cells that have the
same number of chromosomes so are genetically identical to each other and the
parental cell
role of mitosis in growth
increasing cell numbers
repair of tissues
replacement of worn out cells
asexual reproductiin
what is cancer the result of
changes in cells that lead to uncontrolled growth and division
meiosis
division that produces daughter cells, known as gametes,
in which the chromosome number is halved from diploid to haploid so they have
a single set of chromosomes
each daughter cell produced by meiosis will be
genetically different
role of meiosis
reducing the chromosome number
in meiosis, when does the cell have the full chromosome complement again
at fertilisation
asexual reproduction offspring are
genetically identical when no mutations occur
sexual reproduction offspring are
genetically different to eachther and the parents leading to increased variation
most mammals, inluding humans, females are ____ and males are _____
XX
XY
nucleus is the site of
genetic material/chromosomes/genes in plant and animal
cells
what is the genome
the entire genetic material (DNA) of an organism
chromosomes contain
DNA
what is DNAA
a polymer mad eup of two strands forming a double helix
DNA is made from
four different nucleotides, each consisting of a
common sugar and phosphate group along with one of four different bases
attached to the sugar.
adenine pairs with
thymine
guanine pairs with
cytosine
the sequence of dna bases is
the gentic code
genetic code is read as
triplets
each triplet codes for
an amino acid