Biology 1001A Lecture Notes - Chromosome, Mitosis, Meiosis

18 views2 pages

lilachorse745

4 Sep 2013

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

List of mechanisms by which meiosis contributes to genomic diversity: recombination during meiosis (mechanism contributing to copy number variation, unequal crossing over of alleles in recombination gives copy number variation (cnv, random fertilization combinations of egg & sperm. Zygotes bring dna from two different cells into the same cell. Homologous chromosomes carry the same genes w/ different alleles. Homologues have the same genes in the same places. Meiosis 1 reductional division of meiosis (diploid haploid) Meiosis 2 differs in amount of dna (2c 1c) Only makes gametes in some organisms (humans, some animals) Other products of meiosis can be spores (plants) which replicate by mitosis to produce gametophytes to give gametes by mitosis. Plants make gametes by mitosis fungi meiosis produces spores gametophyte gametes zygote meiosis immediately w/o dividing. Molecular biology of recombination with respect to dna backbones & breakage of bonds to cut and paste backbones. Highly controlled enzymatic process w/ recombination enzymes.

Related Questions

Please provide correct answer and explanation to the answer,Thank you!

If an enterprising graduate student decided to repeat theHershey-Chase

experiment but neglected to perform the blending portion, wherewill the

isotopes be found?

a. 35S will be found in the supernatant and 32P will be found inthe pellet

b. 32P will be found in the supernatant and 35S will be found inthe pellet

c. Both 32P and 35S will be found in the supernatant

d. Both 32P and 35S will be found in the pellet

e. None of the above are correct
Chargaffï¿½s rules include:

a. The ratio of Aï¿½s + Tï¿½s to Gï¿½s + Cï¿½s is always consistent

b. A=G and T=C

c. Purines/Pyrimidines = 1

d. More than one of the above are true

e. None of the above are true
Sea Urchin DNA contains 18% guanine (which is true); how muchthymine

does it contain?

a. 9%

b. 18%

c. 32%

d. 36%

e. 64%
E. coli DNA contains a little over 25% guanine. If samples weretaken of E.

coli DNA and Sea Urchin DNA and denatured in water baths, whichwould

melt at a lower temperature?

a. E. coli DNA

b. Sea Urchin DNA

c. They would melt at the same temperature

d. There is not enough information to determine the answer

e. DNA doesnï¿½t ï¿½melt,ï¿½ it isnï¿½t ice cream for goodness sake!
If testing the second generation results in tube B, which modelcan we

conclude is correct?

a. Dispersive

b. Semi-conservative

c. Conservative

d. Semi-dispersive

e. We canï¿½t conclude yet, it could still be more than onepossibility
Phosphorus is required to synthesize dNTPs used in DNAreplication. Imagine

you grow E. coli in media containing non-radioactive phosphorusfor many

generations, then switch the E. coli to media containingradioactive

phosphorous (32P). You then sample the E. coli after one roundof replication

for radioactivity. Where will you find radioactive phosphorus inthe DNA?

a. Both strands will contain 32P

b. One strand will contain 32P

c. Neither strand will contain 32P

d. Drats! I knew I should have done suggested problem 12.19!
Which of the following statements about chromosomes are alwaystrue?

I. Non-histone proteins make up about 5% of a eukaryotic

chromosome by weight

II. Histones have a negative charge

III. Prokaryotes have a single linear chromosome

a. Only Statement I is true

b. Only Statement II is true

c. Only Statement III is true

d. More than one of the above statements are true

e. None of the above statements are true
What portion of the human genome is made up of highly repetitiveDNA?

a. Less than 5%

b. 6 ï¿½ 20%

c. 21 ï¿½ 30%

d. 31 ï¿½ 40%

e. Over 40%
Which of the following statements are always true?

I. Histones are very conserved between species

II. Archaea have nuclei

III. Prokaryotes are haploid and eukaryotes are diploid

a. Only Statement I is true

b. Only Statement II is true

c. Only Statement III is true

d. More than one of the above statements are true

e. None of the above statements are true
An individualï¿½s phenotype is a function of:

a. The alleles they carry

b. The environment they live in

c. The interaction between an individuals genes and theenvironment

d. Two of the above are correct

e. All of the above are correct
A homologous pair of chromosomes showing a

crossover are shown to the right for reference. Are all

the sperm from one human male genetically identical?

a. Yes

b. No, variation occurs during mitosis

c. No, variation occurs during meiosis I

d. No, variation occurs during meiosis II

e. No, variation occurs during both meiosis I and II
Production of gametes in humans requires which kind ofdivision?

a. Meiotic and is reductional

b. Mitotic and is reductional

c. Meiotic and is equational

d. Mitotic and is equational

e. None of the above

scarletmallard658

If an organismâs diploid chromosome number is 18, how many different possible combinations of homologous chromosomes lining up during meiosis exist for the eggs or sperm produced by that organism?

	A.	512
	B.	9
	C.	18
	D.	128
	E.	36

At the end of metaphase I, _______________ separate.

	A.	sister chromatids
	B.	germ cells
	C.	homologous chromosomes
	D.	haploid chromatids
	E.	centrioles

Mendel observed that dominant traits

	A.	are seen in all of the F1 hybrid pea plants in his experiments.
	B.	are expressed in all plants.
	C.	were absent in the F1 generation of pea plants that he used in his experiments.
	D.	were the only traits seen in the F2 generation of pea plants in his experiments.
	E.	are only expressed in hybrids.

Cytokinesis in plant cells differs from cytokinesis in animal cells because

	A.	there is no difference.
	B.	in plant cells, the cell plate must also divide into two parts.
	C.	the contractile protein, actin, is important only in plant cells.
	D.	plant cells have a rigid cell wall.
	E.	a contractile ring forms only in plant cells.

Sickle cell anemia is an example of what type of inheritance?

	A.	complete dominance
	B.	incomplete dominance
	C.	codominance
	D.	multiple alleles
	E.	recessive dominance

Which of the following statements is true:

	A.	The dominant allele is masked in homozygous dominant individuals.
	B.	With recessive genetic disorders, if both parents are carriers, the offspring will all be affected.
	C.	In carriers, the recessive allele causes an intermediate phenotype.
	D.	In recessive genetic disorders, the mother and/or father of an affected individual must also be affected.
	E.	With dominant genetic disorders, the mother and/or father of an affected individual must also be affected.

Skin cancers typically develop in the

	A.	upper layers of the epidermis.
	B.	lower layers of the dermis.
	C.	subcutaneous layer.
	D.	lower layers of the epidermis.
	E.	upper layers of the dermis.

Duchenne muscular dystrophy (MD) is inherited from an X-linked recessive allele. What is the probability that a son with Duchenne MD inherited this disease from his biological father?

	A.	1/2
	B.	0
	C.	1/16
	D.	1/4
	E.	1/8

The genetic makeup of a particular trait in an individual is its

	A.	genotype.
	B.	heterozygosity.
	C.	phenotype.
	D.	filial.
	E.	dominance.

What structure holds the sister chromatids to the spindle fibers?

	A.	chromatin
	B.	kinetochore
	C.	MPF
	D.	centromere
	E.	cyclin

If you view a cell in which the genetic material is beginning to be visible as separate bodies, and the nucleus has disappeared from view, you may surmise that the cells is in

	A.	telophase.
	B.	anaphase.
	C.	interphase.
	D.	metaphase.
	E.	prophase.

Gregor Mendel was successful in his analysis of the genetics of pea plants because

	A.	he examined and analyzed both the F1 and F2 generations.
	B.	he studied the parental plants to determine their differences.
	C.	he decided to only look at his results in an objective manner.
	D.	he studied a trait that had a strange inheritance pattern.
	E.	pea plants have genetics different from other organisms.

Tall corn plants (T) are dominant to dwarf plants (tt). Solid green leaves (G) are dominant to leaves with a white tip (gg). A cross between two corn plants yielded the following phenotypes: 51 tall plants with a white tip on their leaves; 43 dwarf plants with solid leaves; 48 dwarf plants with white tips on their leaves; 45 tall plants with solid leaves. What are the genotypes of the parents that produced these plants?

	A.	None of the above
	B.	TtGg x Ttgg
	C.	ttGG x TTgg
	D.	TtGg x TtGg
	E.	TtGg x ttgg

In humans, a gene that has been identified as causing a type of skin cancer is the

	A.	superwoman echidna.
	B.	mutant superman.
	C.	sonic hedgehog.
	D.	mutant mole rat.
	E.	superhero aardvark.

The segregation principle states that in sexually reproducing diploid organisms the two copies of each gene

	A.	segregate from each other during meiosis.
	B.	must always be the same allele.
	C.	separate from each other during mitosis.
	D.	will both wind up in either the sperm or egg.
	E.	move together as a unit during meiosis.

In what phases is the genetic material in the cell correctly referred to as chromatids?

	A.	metaphase and telophase
	B.	anaphase and metaphase
	C.	interphase and telophase
	D.	interphase and prophase
	E.	metaphase and prophase

Consider two traits for an organism, determined by two genes, each of which is governed by at least two alleles. In the case of a dihybrid individual, the gametes formed will be of either the parental type or the recombinant type. Recombinant type gametes are formed because of

	A.	the principle of dihybrids.
	B.	multiple alleles.
	C.	heterozygosity.
	D.	incomplete dominance.
	E.	independent assortment.

An allele is

	A.	an alternate form of a gene.
	B.	always recessive.
	C.	the main factor determining a trait.
	D.	always one of a pair.
	E.	the dominant form of a gene.

After the DNA is replicated, and it condenses in prophase, two identical rods of DNA are seen. These are

	A.	spindle fibers.
	B.	kinetochores.
	C.	chromatids.
	D.	chromatin.
	E.	centromeres.

Special cells found in the gonads that give rise to gametes upon division are called

	A.	egg cells.
	B.	somatic cells.
	C.	germ cells.
	D.	stem cells.
	E.	basal cells.