Genetics

Question 1

DNA

Answer 1

• located in nucleus

- contains genetic information to control organism

Question 2

RNA

Answer 2

-transfer molecule which moves genetic information and aids in protein synthesis

Question 3

Purine

Answer 3

have double ring structure (larger)

Question 4

pyramidines

Answer 4

have a single ring structure (smaller)

Question 5

nitrogenous base

Answer 5

-connected by H-bonds
-DNA strands run antiparalell
thymine
cytosine
guanine
andanine

Question 6

nucleotide

Answer 6

made of sugar, phosphate bond, nitrogenous base

Question 7

gene

Answer 7

a short section of DNA responsible for inheriting a particular characteristic

Question 8

2 parts of cell division

Answer 8

Interphase-prepare for division grow , mitosis

Question 9

Stages of Mitosis

Answer 9

Prophase- chromatin condenses and form visible chromosomes
Metaphase-the chromosomes move to cell equator
Anaphase- centromeres split and sister chromatin are pulled apear to opposite poles of cell
Telaphase-cell wall pinched and cytokineses(division of cytoplasm

Question 10

function of meiosis

Answer 10

reproductive cells called gametes (egg and sperm)

-mitosis happening twice

Question 11

Gametes

Answer 11

• egg and sperm
• haploid
• each egg and sperm contain 22 autosomes and one sex chromosomes

Question 12

haploid

Answer 12

half the number of chromosomes as humans 23

Question 13

Prophase 1

Answer 13

-nuclear membrane and nucleolus disappear and spindle fibers form
-similar chromosomes pair to form homologous chromosomes
TETRAD- made up of 4 chromatids

Question 14

Metaphase 1

Answer 14

Independent Assortment -pairs of homologous chromosomes line up along the equator randomly
this is called synapsis

Question 15

Anaphase 1

Answer 15

homologous chromosomes separate and move to opposite poles

known as disjunction

Question 16

Telophase 1

Answer 16

-spindle fibers disappear
-cytokineses
no DNA replication 2 chromatids exist
-sometimes a short period of interphase

Question 17

Meiosis 2

Answer 17

identical to mitotic cell division

Question 18

End result of meiosis

Answer 18

-4 non-identical daughter cells
meiosis 1 has diploid set of 46
meiosis 2 has a haploid set of 23

Question 19

gametogenesis

Answer 19

end result in production of gametes

Question 20

spermatogenesis

Answer 20

production of sperm male gametes

equal sperm with head and flagellum

Question 21

oogenesis

Answer 21

production of female gametes (eggs)

• a diploid cell enlarges and undergoes meiosis 1 but cytoplasm is not equally divided
• one cell is viable sex cell called primary oocyte while other 3 are polar bodies.

Question 22

2 ways of genetic variation

Answer 22

1. prophase 1 when tips of non-sister chromatids “cross over” in synapsis and exchange genetic info
2. metaphase 1 - homologous chromosomes independently assort from tetrads

Question 23

non- disjunction

Answer 23

Failure of chromosomes to move to opposite poles in anaphase 1
3 copies of the 21st chromosome
known as down’s syndrome

Question 24

hereditary

Answer 24

transmission of characteristics from one generation to the next

Question 25

allele

Answer 25

particular DNA form that appears at eh gene location an inherited characteristic (Aa)

Question 26

homologous chromosomes

Answer 26

pairs of chromosomes that carry corresponding DNA codes one from mother one from father.

Question 27

Test cross

Answer 27

test preformed to distinguish between homozygous and heterozygous genotype because the phenotype is the same.

Question 28

Incomplete dominance

Answer 28

-both alleles contribute to the phenotype of the heterozygous individual the result is blending inheritance -P= WW(white) x RR(red) F1 : WR (pink) F2: 1WW:2WR:1RR

Question 29

Co dominance

Answer 29

two alleles are expressed at the same time | so mixture of two colors

Question 30

multiple alleles

Answer 30

more than 2 possible alleles

Question 31

Blood types and alleles

Answer 31

A : IAIA IAi B: IBIB IBi AB: IAIB O: ii

Question 32

women men

Answer 32

XX XY

Question 33

3 sex linked disorders

Answer 33

1. Colour blindness 2. Hemophilia 3. Muscular dystrophy

Question 34

Blood Tests

Answer 34

- test for rh factor and blood sugar level - if fetus has rh factor different from mother the mother develops antibodies to the fetus - attack red blood cells - results in brain damage, blood disease, stillbirth

Question 35

Ultrasoud

Answer 35

- visualization of the fetus - physical abnormalities - chormosomal abnormalities are detected through karyotyping

Question 36

Aminocentesis

Answer 36

- 15th and 18th week - needle inserted into abomen and withdraws amniotic fluid - cells cultured in lab - karyotyped during metaphase - chromosome abnormalities detected

Question 37

AFT (alpha-fetaprotien)

Answer 37

protien made in unborn babies - test mothers blood - identify twins - abnormal levels signal nureal tube spinal defect

Question 38

Genetic Mutation

Answer 38

an error in the DNA sequence | may be chromosomal level

Question 39

4 types of chromosomal mutations

Answer 39

1. deletion - portion is lost 2. duplication - chromosome portion is added 3. Inversion - a portion is inverted 4. Translocation : a portion is switched with another

Question 40

Gene therapy

Answer 40

correcting a genetic defect by introducing a normal gene into the defective cells

Question 41

Somatic gene therapy

Answer 41

-introduce gene to somatic cells -hope normal protien is expressed correct symptoms of genetic defect -currently in clinical trials

Question 42

Germ- Line Therapy

Answer 42

- introduce new gene to sperm and egg cells - gene will be transmitted to offspring - common with animals not done with humans