Exam 3 Flashcards
What is a Genome?
Entire DNA content of an organism.
Define Chromatin.
Loose, unpacked DNA in the nucleus.
What is a Centromere?
Region where sister chromatids are joined.
What are Sister Chromatids?
Identical copies of a chromosome joined at the centromere.
What is Mitosis?
Division of the nucleus for growth/repair.
Define Cytokinesis.
Division of the cytoplasm.
What is a Mutation?
Change in DNA sequence (inherited or acquired).
What does Apoptosis refer to?
Programmed cell death.
What is a Diploid cell?
2 sets of chromosomes (46 in humans).
Define Haploid cells.
1 set of chromosomes (23 in humans).
What are Gametes?
Sex cells (sperm/egg) – haploid.
Define Somatic Cells.
All body cells except gametes – diploid.
What is Metastasis?
Spread of cancer to other body parts.
Differentiate between Benign and Malignant.
Benign – noncancerous; Malignant – cancerous/invasive.
What is Nondisjunction?
Chromosomes fail to separate during meiosis.
What does Aneuploid mean?
Abnormal number of chromosomes.
What are Autosomes?
Chromosomes 1–22 (non-sex chromosomes).
What is the human ploidy for diploid?
2n = 46.
List the three functions of Cell Division.
- Growth
- Repair
- Asexual reproduction
Name the types of Asexual Reproduction.
- Binary fission
- Budding
- Fragmentation
- Vegetative propagation
- Parthenogenesis
What are the two parts of the Cell Cycle?
- Interphase
- M Phase
What occurs during Interphase?
- Growth (G1)
- DNA replication (S)
- Prep (G2)
What happens during Prophase of Mitosis?
Chromosomes condense, spindle forms.
During which phase do chromosomes align at the equator?
Metaphase.
What occurs during Anaphase of Mitosis?
Sister chromatids separate.
What happens in Telophase?
Nuclei form.
How does Cytokinesis differ in animals and plants?
Animals: Cleavage furrow; Plants: Cell plate.
What are Stem Cells?
Can become various cell types. Adult vs. embryonic.
How is cancer related to the Cell Cycle?
Caused by failed checkpoints, unregulated division.
What lifestyle factors influence cancer?
- Carcinogens
- Poor diet
- Smoking
What are Proto-oncogenes?
Stimulate division (can become oncogenes).
What is the role of Tumor suppressors?
Stop cell division (e.g., BRCA1/2).
Differentiate between Inherited and Acquired Mutations.
- Inherited: from parents
- Acquired: during life
What are common cancer treatments?
- Surgery
- Chemotherapy
- Radiation
- Immunotherapy
- Targeted therapy
- Hormone therapy
Define Homologous Chromosomes.
Pairs with same genes (1 from each parent).
What is the chromosome number in Gametes?
23 chromosomes each (haploid).
What does XX represent in sex determination?
Female.
What does XY represent in sex determination?
Male.
What triggers male development?
SRY gene on Y.
What occurs in Meiosis I?
Homologous chromosomes separate.
What occurs in Meiosis II?
Sister chromatids separate.
What is crossing over and when does it occur?
Exchange of genetic material during Prophase I.
What is independent assortment?
Random distribution of maternal and paternal chromosomes during Metaphase I.
What is a Nondisjunction example?
Trisomy 21 (Down syndrome).
What is the difference between Genotype and Phenotype?
- Genotype: Genetic makeup (AA, Aa, aa)
- Phenotype: Observable trait
Define Alleles.
Different versions of a gene.
What is a dominant allele?
Expressed if present (A).
What is a recessive allele?
Only expressed if two copies (aa).
What does Homozygous mean?
Same alleles (AA or aa).
What does Heterozygous mean?
Different alleles (Aa).
What is a Testcross used for?
To determine unknown genotype of a dominant phenotype.
List the reasons why Genetic Disorders persist.
- Onset after reproductive age
- Medicine prolongs life
- Heterozygote Advantage (e.g., Sickle cell = malaria resistance)
What are the types of Dominance?
- Complete: Dominant masks recessive
- Incomplete: Blended phenotype (red + white = pink)
- Codominance: Both expressed (AB blood type)
What is Polygenic Inheritance?
Traits from multiple genes.
Provide examples of traits influenced by Polygenic Inheritance.
- Skin color
- Height
Define Multifactorial Inheritance.
Traits influenced by both genes and environment.
Provide examples of Multifactorial Inheritance.
- Heart disease
- Diabetes
Differentiate between Autosomal and Sex-linked traits.
- Autosomal: On chromosomes 1–22
- Sex-linked: On X or Y chromosomes (e.g., hemophilia)
Which is not true of meiosis
Produces genetically identical sales
What is the best definition of genotype?
A set of Ali’s for giving trade
What term describes a gene with two dominant allies that are expressed at the same time
Co dependence
Which types of mutants are acquired
Replication errors in those due to environmental insults
The orca genes and p53 genes are
Tumor suppressor genes
Why do chemotherapy patients have side effects such as hair loss and nausea
Chemo targets, all dividing sales
What is a allele
An alternative form of a gene
The incidence of non-disjunction increases as mother’s age because
Her eggs have been suspended between Miles is one and two
