Genetics and the Cell Cycle

Genes are

• a basic unit of heredity

• genetic material on a chromosome that codes for a functional molecule which will determine a genetic trait

Three aspects of a gene

• genetic material

• chromosomes

• codes for functional molecules

Deoxyribonucleic acid (DNA) is

• permanent info stored in the cell that is passed generationally and between cells (cellular division)

• double stranded (stable)

• Read only memory (ROM): permanent info on a hard drive that allows a computer to run

Ribonucleic acid (RNA) is

• working information inside the cell that is “called up” to complete a process

• short term memory

• random access memory (RAM): working info

• single stranded (easy to remove)

Central dogma of molecular genetics (info flow chart)

DNA→RNA→protein

ROM→RAM→action of the program

Chromosomes are

a discrete portion of DNA in the cells which will contain and organize the genes

prokaryotes contain

a singular circular chromosome which is found in the nucleoid

eukaryotes have

multiple linear chromosomes stored in the nucleus

True or false: both prokaryotes and eukaryotes contain the sequence that makes up a gene

true

Chromosome Complement (C-value paradox) states

number of chromosomes =/= physiological complexity

-ex. humans have 46 chromosomes (23 pairs) but ferns have 1262 chromosomes

autosomes

all other chromosomes (22 pairs)

sex chromosomes

determine sex (1 pair)

polyploidy

extra set of chromosomes

monosomy

only one copy of one chromosome

trisomy

3 chromosomes: extra copy of one chromosome

trisomy 21

3 copies of chromosome 21

monosomy 21

one copy of chromosome 21

chromatin

DNA in the cell

-how DNA is packed in the cell (bound to proteins)

→ 60% protein and 40% DNA

heterochromatin

tightly packed regions of inactive DNA

euchromatin

more loose and able to be used (active DNA expression)