Genetics Flashcards
What is genetics?
The study of heredity and variation
What is eukaryotic sexual reproduction based on?
Meiosis
Fission
Division into two equally-sized offspring
Budding
Unequal division, smaller offspring
Fragmentation
Parent breaks into small new individuals
What is Phylogeny
Evolutionary descent with reflected levels of genetic similarity because of shared evolutionary histories
Where is obligate asexual reproduction found?
Only at the level of individual isolated species within an otherwise sexual genes
What is Sex Determination?
The decision to execute male or female patterns of development
what is Sexual differentiation
The execution of the decision to create a male/female developmental state
What do Leydig cells produce?
Testosterone
What does Anti-Mullerian hormone (AMH) promote?
Other somatic gonadal precursor cells to differentiate into Leydig cells
What do Sertoli cells secrete?
Anti-Mullerian hormone (AMH)
What do somatic gonadal precursor cells differentiate into in males?
Sertoli cells
What do somatic gonadal precursor cells differentiate into in females?
Theca and Granulosa cells
What do Theca and Granulosa cells produce?
Steroid hormones Estradiol and Progesterone
What do genital ridges contain?
Somatic Gonadal Precursor cells?
Where do Germline stem cells migrate into?
Genital ridges from hindgut
What do the genital ridges become?
Indifferent Gonads (contain both somatic gonadal cells and germline stem cells)
Metanephric kidney
Persists as adult kidney
Mesonephros kidney
Embryonic kidney
Cloaca kidney
Single posterior opening - divides to create anal and urethral openings
Wolffian duct
Becomes the vas deferens in males
Mullerin duct
Becomes oviduct in females
Capacitation
Occurs in female tract as sperm swims out of seminal fluid into female tract secretions. Acrosome membrane fuses with sperm cell membrane and exposes sperm receptor for egg protein
Monoblasts
Sponges, only one layer blast cells
Diploblasts
Jellyfish, only 2 layer blast cells
Triploblasts
Flies and humans, three layers of embyronic blast cells
Gastrulation
A movement and reorganisation of cells that is linked to creation of three fundamental layers of blast cells in early embryo
All Bilateria are…?
Tripoblastic
In a 2 factor cross with loci which are closely linked on the same chromosome, the frequency of recombinant phenotypes
Is less than that of the parental phenotypes
When 2 true breeding strains are crossed, the F1 generation will not be uniform in genotype for an X-linked gene
True
At one stage of meiosis, the DNA of each chromosome separates and single DNA strands segregate into daughter cells
False
When 2 true breeding strains are crossed, the F1 generation will not be uniform in genotype for an autosomal gene
False
Two loci are located on non-homologous chromosomes. They segregate independently only if crossing over occurs frequently between them.
False
During prophase I of meiosis, homologous chromosomes pair to form bivalents
True
In interphase, a chromosome is a double stranded molecule of DNA
True
During meiosis, sister chromatids separate at:
Anaphase of Meiosis II
Members of a homologous pair of chromosomes are
Identical in microscopic size and appearance
Two loci are located on non-homologous chromosomes. They segregate independently only if crossing over occurs frequently between them
False
Hemizygosity occurs
In males for genes on the X chromosome
