Natural Selection and Adaptation
Meiosis
Mitosis
Mutations
Inheritance
100
Which organisms are more likely to survive and reproduce: Strong and fit or weak and struggling organisms?
Strong and fit ones.
100
Are the daughter cells in meiosis haploid or diploid?
Haploid.
100
Anaphase
100
What are silent mutations?
A nucleotide changes but no amino acid change occurs.
100
What is this genotype: Aa
Heterozygous.
200
What is natural selection?
Those better adapted to the environment to survive and are more likely to reproduce.
200
Why does meiosis occur? Why can't the cells just go through mitosis?
Because fertilization occurs with 2 parents, they each need to provide half of their DNA to make a baby with 46 chromosomes.
200
Describe what happens in telophase/cytokinesis.
Telophase=nucleus reforms.
Cytokinesis=cytoplasm pinches off and 2 new daughter cells are formed.
200
How can carcinogens and mutagens lead to the development of cancer?
They lead to mutations in DNA.
200
What is the difference between a genotype and a phenotype? Give an example of each.
Genotype=what someone's alleles are; their genetics.
Phenotype=someone's physical traits.
Genotype: bb
Phenotype=blue eyes.
300
What is adaptation?
Natural selection in a population over time.
300
What is independent assortment?
Independent assortment=chromosomes are randomly split into different gametes.
300
What happens in the G2 phase of Interphase?
Organelles duplicate.
300
What is the difference between a missense and a nonsense mutation?
Missense=amino acid changes (can be to any normal amino acid).
Nonsense=amino acid changes to a stop codon.
300
What are the two types of homozygous genotypes?
Homozygous dominant and homozygous recessive.
400
How are antibiotics leading to more resistant bacteria?
The ones who survive are resistant and have resistant daughter cells.
400
What phase of the cell cycle is not repeated twice in meiosis?
Interphase.
400
What can occur if the cell cycle does not happen correctly?
Mutations and cancer.
400
Which of the 4 types of mutations are point mutations?
Silent, missense, nonsense.
400
If the genotypic ratio is: 1 AA: 2 Aa: 1 aa, what percentage of offspring will display the dominant phenotype?
3:1; 75%
500
Draw what directional, stabilizing, and diversifying selection look like.
Directional selection=environment favors extreme phenotype.
Stabilizing selection=middle phenotype is selected for because it is environmentally favored.
Diversifying selection=both extremes are selected for.
500
What are the ways that cells use to increase genetic diversity in gametes? (There are two).
Crossing over (recombinant)
Independent assortment
500
Why is the duplication of DNA and duplication of organelles in different stages of interphase?
DNA is the cell's code to survive. The cell wants to focus on DNA and make it sure it is duplicated correctly before it tells the organelles to duplicate and get ready for cell division.
500
What is a tumor suppressor gene?
Regulates cell growth by using checkpoints.
500
If someone is displaying the recessive phenotype, why do you not need a genetic test to know what their genotype is?
If they are displaying the recessive genotype, they must have the homozygous recessive genotype.