Test 2 - Meiosis and Genetics Flashcards
- The lifecycle of a multicellular organism is?
a. The sequence of stages leading from adults of one generation to the adults of the next
- Humans are what kind of organism
a. Diploid organism
b. Contains two sets of chromosomes
- Human’s gametes are?
a. Haploid – having only one set of chromosomes
- Sexual life cycle involve an?
a. Alternation of diploid and haploid stages
- What happens in meiosis?
a. Haploid gametes are produced in diploid organisms
b. Two consecutive division occur, meiosis I and meiosis II, preceded by interphase
c. Crossing over
- Meiosis I
a. Homologous chromosomes separate
b. Prophase I – Methaphase I – Anaphase I – Telophase I/Cytokinesis
- Prophase I
a. Homologous chromosomes pair and exchange segments (cross over)
- Metaphase I
a. Tetrads line up
b. Microtubules attached to chromosomes
- Anaphase I
a. Pairs of homologous chromosomes split up
b. Sister chromatids remain attached
- Telophase I/ cytokinesis
a. Two haploid cells form: chromosomes are still double
b. Cleavage furrow develops
- Meiosis II
a. Sister chromatids separate
b. Prophase II – Metaphase II – Anaphase II – Telophase II and cytokinesis
- During another round of cell division (meiosis II), the sister chromatids separate to form?
a. Four haploid daughter cells, containing single chromosomes
- The chromosome theory of inheritance states that?
a. Genes are located on chromosomes
- The behavior of chromosomes during meiosis and fertilization accounts for inheritance patterns which are?
a. 1. Law of segregation
b. 2. Law of independent assortment
- Where are genes located?
a. On chromosomes
- Homologous chromosomes have genes where?
a. At specific loci
- What is genetics
a. Branch of biology that deals with heredity and variation
b. The science that attempts to explain the similarities and differences that occur among related organisms
c. Explains the relationship between genes and traits
- Genetics explains life at the level of?
a. Molecules – Dna -> protein
b. Organisms – brown eyes
c. Populations – heterozygote frequency
- Why study genetics?
a. Genetics is relevant to many aspects of human life and society
b. Diseases
- Who is the father of genetics
a. Gregor mendel – planted pea pods
- Mendelian genetics consists of
a. Principle of dominance
b. Principle of segregation
c. Principle of independent assortment
- What is preformation, one early theory of heredity
a. The idea that an organism contains all of its future descendants, encased in increasingly miniature forms, like Russian nesting dolls
- Inheritance timeline 400 BC
a. Greek philosopher Hippocrates proposes that tiny particles from every part of the body of each parent became blended
- Inheritance timeline 350 bc
a. Aristotle dismisses Hippocrates theory – children do not always resemble parents
b. Theory still centers on mixing of “fluids” from each parent
- Inheritance timeline 1700s
a. Scientific thinking about reproduction is dominated by “preformation”
b. Idea that an organism contains all of its future descendants, encased in increasingly miniature forms, like Russian nesting dolls
- Inheritance timeline 1760s
a. Joseph kolreuter pioneers the scientific study of plant hybrids (a “cross” between parents of different varieites
- Inheritance timeline: 1780
a. English livestock breeder Robert bakewell pioneers the systematic breeding of sheep and cattle to obtain higher quality wool and fatter beef
- Inheritance timeline: 1800s
a. Idea of heredity as a “blending” process continues to dominate scientific thought until the late 1800s
- Inheritance timeline: 1856
a. An inquisitive friar named gregor mendel began conductin experiments that held the answer to the riddle
- In mendel’s time, biologists held to the theory of?
a. Blending inheritance – an offspring was an average of its parents
b. Substance (fluids) blended together to yield unique individual with traits from both parents
i. Green + yellow = lime
- The father of horticultural science?
a. Thomas Andrew knight, president of London horticulture society
- Who are the Two plant breeders that paved the way for mendel’s experiments
a. Thomas Andrew knight
b. John goss – English horticulturalist
c. Both were studying ediple pea, pisum sativum
- Why are edible pea or pisum sativum good study subject?
a. Short generation time
b. Small and easy to grow large numbers
c. Inexpensive
d. Numerous varieties available (easily observable traits)
e. Ability to cross fertilize and self fertilize
- Goss’ observation
a. The ability to make short plants is transmimtted from P to F1 to F2
b. Therefore, the F1 has the hereditary particles (genetic information) to make tall and short plants
- Mendel was the first person to?
a. Analyze patterns of inheritance instead of just guessing how traits were passed down from parent to offspring
- How is genetic information transmitted from one generation to the next
a. Not through blending
b. Passing of discrete heritable factors (genes)
- Gregor mendel deduced the fundamental principles of genetics which is?
a. Parents pass on tot their offspring discrete heritable factors (genes) that are responsible for inherited traits
- What did mendel do differently from goss with his garden pea?
a. Limited the number of variables
b. Quantified results
c. Developed possible models that could be tested
- How did mendel limit the number of variables?
a. Started with true breeding (pure breeding) varieties of plants…pure for a specific gtrait P (parental) generation