genetics part one - carter (from notes) Flashcards
what does heredity mean
the passing of traits/genetic info through parent to offspring
where are genes located on the chromosomes?
on the locus (s) / loci (pl)
where are chromosomes found
in the nucleus of eukaryotic cells
what is a eukaryotic cell
a cell with a nucleus
diploid definition
a cell with 2n of chromosomes, one from each parents
haploid definition
cells with one set of chromosomes e.g. sex cells
what is dna made of
nucleotides
who first proposed the structure of dna
watson and crick
2 functions of dna
transmission of traits from parents to offspring, codes for sequence of amino acids and proteins
how many parents are in A nucleotide and what are they
3, base, sugar, and phosphate
what are the four bases and what are their pairs
A,T (adenine and thymine) and G,C (guanine and cytosine)
what is asexual reproduction
offspring are genetically identical to parent (via mitosis)
what are advantages and disadvantages of asexual reproduction
advantages : no specialized anatomy, no mating, heredity is direct and invariable
disadvantages: inability to adapt
advantages and disadvantages or sexual reproduction
advantages: able to adapt to environment
disadvantages: matting calles attract predators, need for specialized organs, may inherit “weaknesses”
what is sexual reproduction
individuals are produced from two sex cells coming together
what is The eukaryotic cell cycle
controlled cyclic event in which the cell divides into two daughter cells, consists of interphase, mitosis and cytokinesis. time varies per organisms
what happens during interphase
G1, organelles and cytoplasm doubles
s, chromosomes double
g2, final growth and organisation
what happens during mitosis
division of chromosomes, PMAT
what happens during cytokinesis and when does it start
cytoplasm splits, cells split into two daughter cells, starts during anaphase
whats the purpose of mitosis in multi-cellular and uni-cellular organisms
multi - for growth, repair, replacement and more surface area for better exchange of material
uni - for reproduction
why are cells so small?
as a cell grows, surface area to volume ratio decreases, therefore less surface area for transport of materials.
cells aren’t as efficient so they divide into 2 or more efficient smaller cells
what is a chromosome
dark straining body that contains DNA
which cells don’t replicate
inner ear, heart muscle, and brain
what is the long stringy form of chromosomes called
chromatin