Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
74 Cards in this Set
- Front
- Back
|
When an organism does not divide itself to create offspring how does it replicate?
|
sexual reproduction
|
|
|
What two haploid cells meet to create offspring?
|
egg and sperm
|
|
|
Sexually reproduced offspring look different than their parents because they have different
|
DNA
|
|
|
What is a mature sexual reproductive cell, as a sperm or egg, that unites with another cell to form a new organism?
|
a gamete
|
|
|
What are two important characteristics of the reproductive cell called the egg
|
large,
lots of cytoplasm |
|
|
What are two important characteristics of the reproductive cell called the sperm?
|
small
motile by use of a flagella |
|
|
How much of an organism's somatic DNA is contained in gamete?
|
half or 23
|
|
|
When two gametes combine, how much somatic DNA is in the new cell?
|
a full set of 46
|
|
|
Define somatic cells:
|
Cells 0f the body. (As opposed to other types such as germ cells.)
|
|
|
How many chromosomes are in a garden pea somatic cell?
|
14
|
|
|
How many chromosomes are in the somatic cell and the gamete cell of a horse?
|
64 and 32
|
|
|
How many chromosomes are in the somatic cell and the gamete cell of a frog?
|
26 and 13
|
|
|
What is the purpose of the cytoplasm in an egg?
|
To supply nutrients for the zygote to become an embryo.
|
|
|
What process allows a cell to divide to form gametes?
|
meiosis
|
|
|
What are homologous pairs of chromosomes?
|
Chromosomes that have the same genes in the same order of arrangement. They may have variations in the alleles such as hair or eye color.
|
|
|
Where do an organism's homologous chromosomes come from?
|
One from the mother and one from the father.
|
|
|
How many chromosomes come from each homologous chromosome in humans?
|
23
|
|
|
Name three features that are the same in homologous chromosomes?
|
the location of the centromere,
the size of the chromosomes, the legs of the chromosomes |
|
|
How many chromosomes does a diploid organism have?
|
2n or 2 times the number of different types of chromosomes
|
|
|
What is the human diploid number?
|
46 or 2n=46
|
|
|
What is the number of chromosomes in a gold fish?
|
94 or 2n = 94
47 from each parent |
|
|
What is the number of chromosomes in a fruit fly?
|
8 or 2n = 8
4 from each parent |
|
|
What are organisms called that do not have diploid cells?
|
haploid organisms
number of chromosomes = n |
|
|
What are the two haploid cells in humans?
|
sperm and egg
|
|
|
What is the mechanism for reproduction of bacteria?
|
binary fission
|
|
|
How many chromosomes in mice are in their gametes if n=20, and how many in a somatic cell?
|
20
40 |
|
|
How many chromosomes in dogs are in their gametes if n=36, and how many in a somatic cell?
|
36
2n = 72 |
|
|
How many chromosomes in ducks are in their gametes if n=40, and how many in a somatic cell?
|
40
2n = 80 |
|
|
How many chromosomes in frogs are in their gametes if n=13, and how many in a somatic cell?
|
13
2n = 26 |
|
|
What is fertilization?
|
The process in which the egg and sperm cell meet.
|
|
|
What is a zygote?
|
The single cell that results from fertilization.
|
|
|
What does the zygote become and is it diploid or haploid?
|
a fetus, and it is diploid
|
|
|
What happens to the flagella of the sperm when fertilization occurs?
|
It falls off.
|
|
|
To make gametes with half the amount of DNA, cells undergo:
|
meiosis
|
|
|
What are female gametes called?
|
eggs
|
|
|
What are male gametes called?
|
sperm
|
|
|
What are the primary phases of meiosis I?
|
prophase I (PI)
metaphase I (MI) anaphase I (AI) telophase I (TI) |
|
|
What are theprimary phases of meiosis II?
|
prophase I (PII)
metaphase I (MII) anaphase I (AII) telophase I (TII) |
|
|
What phase comes before meiosis?
|
interphase
|
|
|
What phase comes after each meiosis?
|
cytokinesis
|
|
|
What is meiosis in females called?
|
oogeneis when a primary oocyte is produced
|
|
|
What is an oocyte?
|
an immature egg
|
|
|
How many viable eggs can be produced from one oocyte?
|
one
|
|
|
What forms at the same time as the secondary oocyte but are much smaller and not viable?
|
polar bodies that are reabsorbed
|
|
|
What is in the polar body?
|
one set of chromosomes
|
|
|
When do primary oocytes form in a woman?
|
prior to birth
|
|
|
What stage are oocytes in from birth until sexual maturity?
|
the diplotene stage of prophase I or the dictyate stage
|
|
|
When do oocytes complete meiosis?
|
During puberty they become activated, and after puberty normally one egg completes meiosis once a month.
|
|
|
What is spermatogenesis?
|
The production of sperm through meiosis in males.
|
|
|
How many sperm are produced in male humans during spermatogenesis?
|
millions (over 300 million)
|
|
|
What happens during Interphase I of meiosis?
|
DNA and organelles replicate
|
|
|
What happens during Prophase I of meiosis?
|
chromatin condenses into chromosomes, the nuclear envelope disappears, a spindle apparatus begins to form, homologous chromosomes pair up and become attached in a tetrad, centrosomes migrate to opposite sides of the cell
|
|
|
What is crossing over?
|
Crossing over occurs when the chromosomes of the homologous pair become tangled during prophase I, and genetic recombination can occur.
|
|
|
What happens during Metaphase I of meiosis?
|
Tetrads, or homologous pairs, line up on the metaphase plate; spindle fibers attach to each chromosome at the kinetochore on the centromere; spindle fibers anchor on the centrosome.
|
|
|
What happens during Anaphase I of meiosis?
|
homologous chromosomes are pulled apart by the spindle fibers and centrosome; each chromosome of a homologous pair is pulled to the opposite side of the cell
|
|
|
What happens during Telophase I of meiosis?
|
a cleavage furrow or cell plate begins to form down the middle of the cell; each of the resulting cells is haploid but the chromosomes consist of two sister cells that are identical to each other.
|
|
|
What happens during Prophase I of meiosis?
|
the microtubules pull the pairs of homologous chromatids towards each pole as the tetrad is divided; the cell begins to lengthen
|
|
|
What happens during Cytokinesis I of meiosis?
|
the cells split into 2 daughter cells that are 2N, 2C
|
|
|
What is Interkinesis?
|
Interphase II of meiosis is called interkinesis. No DNA replication occurs during Interkinesis, only rest.
|
|
|
What happens in Prophase II of meiosis?
|
chromosomes line up at the center of the cell; spindle fibers attach to the centromere at the kinetochore; the chromosomes are in single file
|
|
|
What happens in Prophase II of meiosis?
|
The centrioles duplicate. This occurs by separation of the two members of the pair, and then the formation of a daughter centriole perpendicular to each original centriole. The two pairs of centrioles separate into two centrosomes.
|
|
|
What happens in Anaphase II of meiosis?
|
sister chromatids are pulled apart by the spindle fibers to opposite ends of the cell
|
|
|
What happens in Telophase II of meiosis?
|
the cleavage furrow finishes development, and the cytoplasm divides. There are 4 daughter cells, and each has half the amount of DNA as the parent cell.
|
|
|
What is the difference between the sperm and egg cells of one person?
|
The type of alleles each contains.
|
|
|
Is the order that chromosomes line up on the metaphase plate during Metaphase I random or fixed? Why?
|
Random so that there are different combinations of genes in each sperm or egg cell.
|
|
|
What is the random assortment of chromosomes during Metaphase I called?
|
independent assorment
|
|
|
What is recombination in meiosis?
|
Recombination is when the homolgous pairs become tangled up in prophase I and swap genes.
|
|
|
What two processes contribute to the genetic variation between brothers and sisters?
|
independent assortment and crossing over
|
|
|
What is the type of cell division that splits the number of chromosomes in half and produces gametes?
|
meiosis
|
|
|
How many times does a cell divide to produce gametes?
|
2
|
|
|
What is the term for daughter cells produced in female meiosis that are not viable eggs?
|
polar body
|
|
|
What is the term for the first cell produced from the union of the sperm and the egg?
|
zygote
|
|
|
What allows a sperm cell to be motile?
|
flagella
|
|
|
Why is an egg cell larger than a sperm?
|
It contains cytoplasm as food for the growing fetus.
|
