Midterm Review Flashcards
During which phase of the cell cycle does the cell carry out its normal functions?
Growth 1
During which phase of the cell cycle does the DNA replicate and why is it before the cell divides?
S phase - before the cell divides so that the new cells have an exact complete set of chromosomes
What is the role of cyclins and kinases in the cell?
Control the cell
What happens in the G2 phase of the cell cycle?
Final growth and critical checkpoints before mitosis
What are the steps of mitosis in the correct order?
Prophase, Metaphase, Anaphase, Telophase
When in the cell cycle does the cytoplasm divide (what phase does it follow)?
Follows Telophase
What is the division of the cytoplasm called?
Cytokinesis
What is the difference between diploid and haploid cells?
Haploid- 1 set of chromosomes, ex. include reproductive cells and gametes
Diploid- 2 sets of chromosomes, ex. include somatic/body cells
How many chromosome are found in human body cells?
46
When does crossing over take place?
Meiosis 1 (Prophase 1- when homologous chromosomes line up)
How does meiosis/crossing over help with the continuation of a species?
Provides genetic variation
Describe the process of Meiosis’s first phases of PMAT
Prophase 1- homologous chromosomes appear and crossing over occurs (leads to variation)
Metaphase 1- homologous chromosomes line up along the middle of the spindle
Anaphase 1- Homologous chromosomes separate and are pulled to opposite ends of the cell
Telophase 1- Spindle fibers disassemble and cell undergoes cytokineses and is ready for PMAT 2
Describe the process of meiosis 1
Division of homologous chromosomes
Describe the process of meiosis 2
Sister chromatids are divided to make four haploid cells
What is cancer?
Uncontrolled cell growth
What effect do cancer cells have on other healthy cells?
Cancer cells deprive health cells of nutrients
What is the difference between a malignant and benign tumor?
Benign- doesn’t move
Malignant- moves to other parts of the body
What are stem cells?
Unspecialized cells that have not yet differentiated
What is/results from nondisjunction?
Failure of the chromosomes to separate correctly thus resulting in too many or too few chromosomes
What is a photo of an organism’s chromosomes called?
Karyotype
Who was the father of genetics?
Mendel
What are Mendel’s three laws?
- Law of Dominance- dominant allele is expressed when it is present
- Law of Independent Assortment- Allele pairs separate independently of each other during gamete formation
- Law of Segregation- organism inherits 2 copies of each gene, one from each parent. Organisms can only donate one copy of each gene in their gametes
Which of Mendel’s Laws is an explanation of the variation between species?
Law of Independent Assortment
Which of Mendel’s Laws states that organism inherit two copies of each gene, one from each parent?
Law of Segregation
What is the genotype of a person with a recessive disorder?
Homozygous Recessive
What do you call a distinguishing characteristic that can be inherited?
Trait
What is the difference between dominant and recessive traits?
Dominant- expressed if present in genotype
Recessive- only seen if a dominant allele is not present to mask it
What chromosomes determine the sex of the offspring?
Sex Chromosomes
What is the sex of a human with chromosomes “XX”?
Female
What is the sex of a human with chromosomes “XY”?
Male
With X-linked traits (such as colorblindness) why are males more often colorblind compared to females?
They only have one X chromosome
What is the process that produces an exact copy of DNA?
Replication
During which phase of the cell cycle does the DNA replicate?
Synthesis
What does semi-conservative mean?
Gives a copy- not original, translates to mRNA
What do we call organisms that have altered genes or genomes
Genetically Engineered
Which scientists discovered the shape and built a model of DNA?
Watson and Crick
What is the shape of DNA?
Double Helix/Twisted Ladder
What are the base pairing rules for DNA?
A -> T
C -> G
What is transcription?
DNA is converted into mRNA
Which enzyme builds and “proof reads” DNA while replicating?
DNA Polymers
What does the central dogma state?
DNA -> RNA -> Protein
What are the three letter sequences in RNA called?
Codon
What is a point mutation or a substitution?
Only one base is incorrect
What is frame-shift mutation?
Base is either inserted or deleted (most destructive)
Where in the eukaryotic cell is the DNA located?
Nucleus
What is DNA composed of?
Nucleotides
What is the difference between the three types of RNA?
- mRNA- carries message or instructions that will be changed into amino acids
- tRNA- carries/transfers amino acids to ribosomes
- rRNA- located in ribosomes & does the building
What is the sequence of the entire DNA in an organism (every chromosome)?
Genome
