Cell division, genetics and molecular biology

Question 1

Interphase

Answer 1

Question 2

Spermatogenesis

Answer 2

Production of sperm begins at puperty

Uses the process of meiosis1 and meiosis 2 - haploid

Question 3

Oogenesis

Answer 3

Production of eggs begins at birth

Use the process of meiosis 1 and meiosis 2 - haploid

Monthly cycle - out of the 4, 1 survives and 3 die

Question 4

Meiosis = unidentical cells

Answer 4

Haploid; n=23

Gametes

Cell division in sexual reproductive strategies

Question 5

Stages of mitosis = identical cells

Answer 5

PMAT

Prophase - DNA - chromosomes, nuclear membrane brakes down, centriollies provide attachments for spindle fibers that help move chromosomes

Metaphase - chromosomes line up on equatorial plate

Anaphase - spindle fibers shorten, 2 sister chromosomes are seperated

Telophase - chromosomes reach destination, clevage furrow forms, nuclear membrane reforms, spindle fibers disintegrate

Question 6

Conjugation (Prokaryotes)

Answer 6

Transfere of genetic material from 1 cell to another by cell to cell contact.

Question 7

Binary Fiusion (Prokaryotes)

Answer 7

Cell dividing method used by bacteria; used when bacteria have only 1 circular chromosome and no nucleus.

Question 8

Sexual reproduction

Answer 8

Involves the production of gametes by meiosis followed by fertilization between genetically distinct parental gametes to produce genetically distinct offspring, meiosis to create haploid gametes

Question 9

Asexual reproduction

Answer 9

The reproductive in which a parent organism produces genetically identical offspring

Mitosis to create identical offspring

Question 10

Faternal twins

Answer 10

2 oocytes are released instead of one

Question 11

Identical twins

Answer 11

Single zygotes splits into 2 seperate bodies in the first few days

Question 12

Nondisjunction

Answer 12

When homologous chromosomes/chromatids do not seperate

Monosomy - 1 less chroosome 45 chromosomes

Turner syndrome-female with 1x chromosome

Kinifler syndrome 2x and 1y chromosome

Trisomy - 1 more chromosome 47 chromosomes 21=down syndrome 18=edward syndrome

Symptoms - ceased tounge, big forhead and mental disabilities

Question 13

Independent assortment

Answer 13

During metaphase 1, chromosomes are arranged in homologus pairs along the equator plate of the cell. In each pair the chromosomes of the maternal origin is oriented toward one pole of the cell while the chromosome of parental origin is oriented towards the other pole.

Question 14

Crossing over

Answer 14

As paris of chromosomes come together the chromatids will interwine

Question 15

Karyotype

Answer 15

The set of chromosomes that an individual possess

Question 16

Sex - linked traits

Answer 16

Sex-linked traits are traits determined by genes
located on sex chromosomes (usually the X
chromosome)
The symbols for sex linked traits are written with a
capital X and a superscript of the letter
representing the allele i.e. hemophilia - Xh

Question 17

X - Chromosomes

Answer 17

It has been estimated that the human X chromosome
carries between 100 and 200 different genes
Sex linked traits include: color blindness, hemophilia,
night blindness, near sightedness, male pattern
baldness and Duchenne Muscular Dystrophy
Many recessive lethal X-linked disorders occur more
often in males

Question 18

Sex-linked traits

Answer 18

More males will express the trait than females
Females will be carriers but will not express the trait
– are able to pass it onto their children

i.e. hemophilia, color blindness, Duchenne muscular
dystrophy

Question 19

Crossing over

Answer 19

Crossing over - occurs during prophase I when
homologous pairs sometimes have sections that flip
This results in more diversity than expected
The farther apart the genes the more likely crossing
over is going to occur compared to those genes that
are closer to the centromere