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69 Cards in this Set

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What did Otto Hertwig observe?
Fertilizatin oinvolved fusion of sperm and egg nuclei.
What did Walter Flemming describe?
Key events of the cell division process, (mitosis)
What did Edouard von Beneden describe?
The appearance of rodlike structures during fertilization in the horse-worm Ascaris megalocephala
Who named chromosomes?
Wilhelm Waldeyer
What did Otto Hertwig observe?
Fertilizatin oinvolved fusion of sperm and egg nuclei.
What did Walter Flemming describe?
Key events of the cell division process, (mitosis)
Do chromosomes split along the latitude or longitude during mitosis?
Longitude
What did August Weismann deduce?
Genetic material must be halved in the production of sperm and eggs.
What did Edouard von Beneden describe?
The appearance of rodlike structures during fertilization in the horse-worm Ascaris megalocephala
What did Wilhelm Roux propose?
Chromosomes are transmitted equally to the daughters of mitosis.
Who named chromosomes?
Wilhelm Waldeyer
What are homologous chromosomes?
Contain same genes, but may have different alleles for each gene.
Do chromosomes split along the latitude or longitude during mitosis?
Longitude
Can homologous chromosomes have different alleles?
Yes
What did August Weismann deduce?
Genetic material must be halved in the production of sperm and eggs.
Are chromosomes condensed during interphase?
No
What did Wilhelm Roux propose?
Chromosomes are transmitted equally to the daughters of mitosis.
When does recombination occur?
Meiosis I, between homologous chromosomes
What are homologous chromosomes?
Contain same genes, but may have different alleles for each gene.
Describe the stages of mitosis.
Prophase - chromosomes condense; nuclear membranes begin to break down

Metaphase - Nuclear membrane is broken down; chromosomes line up at metaphase plate.

Anaphase - Sister chromatids separate

Telophase - Chromosomes arrive at opposite poles; nuclear membrane re-forms
Can homologous chromosomes have different alleles?
Yes
How many chromosomes does each daughter cell have after Meiosis I?
Half the number of diploid, but each are composed of 2 sister chromatids.
Are chromosomes condensed during interphase?
No
Where are the mitosis cells from?
Onion root tip
Where are the meisis cels from?
Anthers of lily buds
When does recombination occur?
Meiosis I, between homologous chromosomes
Describe the stages of mitosis.
Prophase - chromosomes condense; nuclear membranes begin to break down

Metaphase - Nuclear membrane is broken down; chromosomes line up at metaphase plate.

Anaphase - Sister chromatids separate

Telophase - Chromosomes arrive at opposite poles; nuclear membrane re-forms
How many chromosomes does each daughter cell have after Meiosis I?
Half the number of diploid, but each are composed of 2 sister chromatids.
Where are the mitosis cells from?
Onion root tip
Where are the meiosis cells from?
Anthers of lily buds
What are the two beakers labeled?
HCl and Carnoy's
What percentage is the HCl?
18%
Where do you place the root tips?
Into the 18% HCl for 4 minutes
How long do you place the root tips in the HCl?
4 minutes
What does the HCl do?
Softenst the tissue in preparation for staining and squashing
What do you do after you put the root tips in the HCl?
Put it int Carnoy's solution for at least 4 minutes
How long do you put the root tips in Carnoy's solution?
4 minutes
What does Carnoy's solution do?
It is a fixative tat preserves the structure of the cells.
How long can root tips remain in Carnoy's solution?
Indefinitely
How much of the root tip do you cut off?
All but the last 1-2 mm atof the tip
How can you tell the growing tip from the rest?
It is slightly tapered and slightly whiter in color
What objective do you start with?
Low power, (4x or 10x)
Describe what happens at 400x magnification.
Light moving from air to glass or from glass to air bneds and results in loss of resolution above 400x.
How can a magnification of 1200x be achieved?
If the air between the lens and the slide is replaced with oil, because oil has the safe refractive index as glass, so light will not bend and become distorted
What dictates the upper 1200x limit?
Wavelength of the light
What lens do you want to make sure does not come in contact with the oil immersion?
40x
What shooting mode do you want the camera on?
Auto
Do you want the flash on on the camera?
No
What is pollen essentially?
Sperm
What are the diploid cells int he anther called?
Meiocytes
When meiocytes undergo meiosis, what do they produce?
Spherial tetrads, each containing 4 hpaloid cells, which then mature into pollen grains
What type of stain do you use on the antler?
Acetocarmine stain
How do you smash and chop the anther?
With the side of a dissecting needle in the pool of stain
What will too much pressure on the meiocytes do?
Lyce the cells and make the stages of meiosis difficult to discern
Should you use the 100x oil immersion lens with the meiocytes?
No, because they are large and fragile and will be crushed
How long does mitosis usually take?
1/2 hour to 2 hours
When do the spindles form?
Metaphase
What is the region of the centromere that the spindle fibers attach to called?
Kinetochore
How is meiosis more complex in plants?
Meiosis forms sports, which undergo one or more mitotic divisions to produce a haploid gametophyte organism, which produces gametes by mitotic division of a haploid nucleus; fusion ofhaploids creates a diploid zygote that developes into a sporophyte plant
What are the five substages of prophase I in meiosis?
leptotene
zygotene
pachytene
diplotene
diakinesis
What is leptotene?
Chromosomes first become visible as long thread-like structures'; chromomeres
How can sister chromatids in the leptotene be distinguished?
Electron microscop
What are chromomeres?
Dese granules that appear at irregular intervels along the chromosomes in
What is zygotene?
Synpsis of homologous chromosomes, beginning at the chromosome tips
What are the synpased homoglous chromosomes in zygotene referred to as?
Vialent
What happens during pachytene?
Condensatin of the chromosomes continues; each bivalent actually consists of a tetrad of four chromatids, but the two ister chromatids are usually juxtaposed very tightly; crossing-over takes place
What occurs during pachytene?
Crossing over
What happens during diplotene?
The synapsed chromosomes begin to separate and the diplotene chromosomes are clearly double; but the homologous chromosomes remain held together at the chiasma
What happens during diakinesis?
Homologous chromosomes repel each other and the segments not connected by chiasma pull apart