Cell Biology Basics Flashcards
A typical animal cells is what type of cell?
Somatic
DNA
Deoxyribonucleic acid
- Molecular made of nucleotides
Nucleotide components
1.) Sugar-phosphate backbone
2.) Base (A, T, C, G)
Who was the first to discover DNA?
Rosalind Franklin
Wilkins, working on DNA structure at King’s College
BUT Watson and Crick received all the credit (working on DNA structure at Cambridge)
Chromatin and condensed chromosomes structure
Chromatin wraps around histones and condenses to form chromosomes
23 pairs of chromosomes (46 total)
- 23 from mother
- 23 from father
What are the two main functions of DNA?
1.) Protein synthesis
2.) Replication
Somatic cells
Diploid in nature
- A cell that contains two copies of the genome (46 chromosomes)
Gamete cells
Haploid in nature
- A cell that contains one copy of the genome (23 chromosomes)
Mitosis
Process of replicating somatic cells
Meiosis
Process of replicating gametes
Before cell division can take place, what must happen?
DNA in the nucleus is doubled
Outcome of mitosis
Daughter cells have the same amount of genetic information as starting cell
- each daughter cell has the complete amount of genetic material– 23 pairs of chromosomes (46 total)
Outcome of meiosis
Daughter cells have only have the genetic information; this information is shuffled up into new combinations
T/F Eggs bring all the organelles and cytoplasm
True
Mitochondria DNA (mtDNA) comes only from mother
Nuclear DNA
IF a Y chromosome is present, the sperm contributed it
Y chromsome is short
- males have only one allele from some traits on X
- males will show recessive phenotypes more frequently
Mutations
Errors that occur during DNA replication and cell division
Mutation
- original source for all the genetic variation that exists in our species
- mutations not necessarily bad
(Mutations can be detrimental, beneficial, detrimental in some environments but beneficial in others, and can be neutral in effect) - effect of a mutation depends on when and where it occurs
Mutations that occur during mitosis
Will NOT be passed on
Mutations that occur during meiosis
HERITABLE
Mutations in coding vs. noncoding regions of the genome
Only coding regions will show up in phenotype
Transcription and translation
the process of turning DNA into proteins
Transcription
Happens in the nucleus
Translation
Happens in the cytoplasm
Flow of protein synthesis
Amino acid –> Polypeptide chain –> protein
Protein
A chain of amino acids (and other stuff) that does stuff in a cell
- folds up into a specific shape
- shape=function
Maintain structure
Collagen
Move stuff around
Hemoglobin
Break stuff down
Enzymes
Alter tissues
Hormones
Gene
A DNA sequence that codes for a functional RNA product (not including spliced out introns)
Alternative splicing
A given DNA sequence can make multiple mature mRNA sequences and thus multiple different proteins
Gene expression controls what?
Cell specialization
- Regulatory genes control gene expression
When a sequence of DNA is undergoing the process of transcription and translation…
A gene is being expressed
Gene expression can be… in different cells at different times
“turned on” or “turned off”
What is crossing over/recombination?
The exchange of DNA between paired homologous chromosomes (one from each parent) occurs during the development of egg and sperm cells (meiosis). This trading of genetic material creates unique chromosomes that contain new combinations of alleles
