Exam 3

Question 1

Photosynthesis

Answer 1

the process that converts solar energy into chemical energy within a chloroplast

6CO2+12H2O+light energy ——->C6H12O6+6O2+6H2O

Question 2

Light dependant reactions

Answer 2

Happened in the membrane of the thyalkoid, protons are pumped from the stroma into the thylakoid lumen

reactants: photons and water
products NADPH and ATP

light absorbed into PSII, exciting an electron and passed down the ETC, providing energy for the proton from water (which comes from the oxidation of water) to be pumped across the membrane to create a gradient. light is again absorbed in PSI and electrons are excited again and transferred down the chain. @ the very end of the chain electrons are passed to NADP+ to make NADPH. ATP synthase then pumped the protons back over the membrane creating ATP

Question 3

Calvin Cycle (light independent reactions)

Answer 3

In the stroma

1 CARBON FIXATION: 3 molecules of Carbon dioxide to start, carbon has been removed from the atmosphere and fixed into an organic molecule, rubisco, then becomes 6 3-PGA

2 REDUCTION of 3-PHA to G3P: ATP is used to convert 3 PGA into 1, 3-bisphosphoglycerate
NADPH electrons reduce it to 6 glyceraldehyde-3-phosphate (G3P)
3CO2»» 6 G3P
Only 1 G3P molecules are used for carbohydrates
the other 5 G3P molecules must be used for the regeneration of RuBP

3 REGENERATION of RUBp: 5 G3P are converted into 3 molecules RuBP using ATP

Question 4

Genome

Answer 4

All the DNA in a cell

Consists of a single DNA molecule or a number of DNA molecules

Question 5

Chromosome

Answer 5

Packages of genetic information

**humans have pairs 23 pairs or 46 chromosomes

Question 6

Autosomes

Answer 6

a type of gamete (doesn’t include sex chromosomes s the xx or xy)

22 pairs in humans

Question 7

Sex chromosome

Answer 7

1 pair (xx or xy)

Question 8

Haploid

Answer 8

single chromosomes

represented by n (only 23 chromosomes)

gametes

Meiosis

Question 9

Diploid

Answer 9

two chromosomes

represented by 2n

somatic cells (all different cells in the body)

created by mitosis

Question 10

Somatic cells

Answer 10

(Non representative cells) have two sets of chromosomes

Question 11

Gametes

Answer 11

(Reproductive cells sperm and egg cells)

Have only 23 chromosomes (half as many as somatic cells because they combine with the egg and the sperm to produce a total of 46 chromosomes)

Question 12

Homologous chromosomes

Answer 12

Look the same, control the same traits, may code for different forms of each trait, made of sister chromosomes joined at centromere

Question 13

G1 phase (interphase)

Answer 13

Cell growth occurs

Signaling molecules can cause cell to accumulate molecular changes during g1 that promote progression through the cell cycle

If the cell passes the check pt (restriction pt) then it continues to S phase. If not then it goes into G0 pahse

Question 14

G0 phase

Answer 14

phase in which cells go when they don’t pass the checkpoints in mitosis

In this phase, the cells are neither dividing or preparing to divide

Question 15

S phase

Answer 15

Chromosomes replicate

After replication 2 copies stay joined together and are called sister chromatids

Question 16

G2 phase

Answer 16

Cell synthesizes proteins needed during mitosis and cytokinesis

Organelles replicate

46 pairs of chromatids/92 chromatids total

Question 17

Checkpoints in mitosis

Answer 17

G1 checkpoint: restriction point, checking to see if the cellis ready to divide, if not goes into G0 phase

G2 checkpoint: checking DNA

M checkpoint: check chromosomal alignment

Question 18

Mitosis phase order

Answer 18

Interphase (G1, S, G2)

Mitosis (prophase, prometaphase, metaphase, anaphase, telophase)

Cytokinesis

Question 19

Prophase

Answer 19

Nuclear membrane dissociates into smallvesciles chromatids condense into highly compacted structures (visible by light)

Mitotic spindles form

Question 20

Prometaphase

Answer 20

Nuclear envelope complete fragments

Mitotic soindle fully formed

Cpindle fibers interact, 2 kinetochores on each pair of sister chromatids are attached to kinetichore microtubules from opposite poles

Question 21

Metaphase

Answer 21

Pairs of sister chromatids are aligned along a plane halfway brown the poles (metaphase plate)

Organized into a single row

Question 22

Anaphase

Answer 22

Connections broken brown sister chromatids

Each individual chromatid slinked to one pole by the minted horse microtubules

Microtubules shorten pulling chromosomes toward pole where they are attached

Question 23

Telophase/cytokinesis

Answer 23

Chromosomes have reached respective poles and deco dense

Nuclear membranes now reform to produce two separate nuclei

Question 24

Cytokinesis

Answer 24

Process called cleavage, first shown by the sign of a cleavage furrow and cell plate in plant cells

Question 25

Mitotic spindle

Answer 25

Composed of microtubules, Centriols ones which duplicate at beginning of mitosis organize chromosomes

Question 26

Kinetochore

Answer 26

Center of chromosome associated with centrimeres microtubules attach to kinetochore

Question 27

Heredity

Answer 27

The transmission of traits from one generation to the next

Through gametes

Question 28

Meiosis

Answer 28

Nuclear division that precedes the formation of gametes resulting in a halving of chromosomes forming a haploid cell

I 2 haploid cells
II 4 haploid cells

Question 29

Synapasis

Answer 29

Joining of DNA from one non sister chromatids to the corresponding segment of another allowing crossing over to occur

Happens in prophase I

Question 30

Synaptonmal complex

Answer 30

A protein complex connecting homologous chromosomes

Question 31

Crossing over

Answer 31

Physical exchange brown chromosome pieces of the crossing bivalent REGULATED

Question 32

Chiasma

Answer 32

Arms of the chromosomes separated but remain adhered at the cross over line

futher def: the point of contact or the physical link between two chromosomes in a tetrad as they are crossing over in porphase I

Question 33

Genetics

Answer 33

Branch of biology that deals with heredity and variation of organisms

Question 34

Gene

Answer 34

Unit of heredity

A section of dna sequence encoding a single protein

Question 35

Genome

Answer 35

The entire set of genes in an organism

Question 36

Alleles

Answer 36

2 genes that occupy the same position on a homologous chromosome and that cover the same trait

onefrom the mother and one from the father

ex. RR, Rr, rr

Question 37

Locus

Answer 37

A fixed location on a strand of dna where a gene or one of its alleles is located

Question 38

Dominant

Answer 38

The allele of a gene that makes or suppresses the expression of an alternate gene

Question 39

Recessive

Answer 39

An allele that is masked by a dominant allele only appearing when in the heterozygous condition

Question 40

Monohybrid cross

Answer 40

Genetic cross involving a single pair of genes

Question 41

Law of independent assortment

Answer 41

the inheritance of one pair of genes is independent of the inheritance of another pair

Question 42

Law of segregation

Answer 42

every individual possesses two alleles and only one allele is passed on the to offspring

Question 43

Law of dominance and uniformity

Answer 43

One allele masks another; one allele was dominant over the other in the F2 generation

Question 44

Autosomal mutation

Answer 44

Caused by alleles on autosomes

Chromosomes instead of sex chromosomes

Question 45

Sex linked mutation

Answer 45

Caused by mutation in X chromosome (most of the time)

Question 46

Sex linked gene

Answer 46

Gene located on either sex chromosome

Question 47

X linked genes

Answer 47

Genes found on the x but not on the y

Most sex linked traits are on the x

I order to be expressed a female needs two copies of the allele and a male needs only one copy of the allele