Where does fertilization usually occur?
In a female animal, how many eggs will result?
After telophase I of meiosis, the chromosomal makeup of each daughter cell is
haploid, and the chromosomes are composed of two chromatids
In a male animal, how many sperm will result?
Chromosomes first form tetrads during
prophase of meiosis I
The order in which sperm pass through the structures from the testes to fertilization of the egg is
epididymis, vas deferens, urethra, vagina, cervix, uterus, oviduct
One menstrual cycle (not flow stage) usually lasts about a
Mitosis is the process by which
the nucleus divides into two nuclei
The testes and the ovaries do not begin producing mature reproductive cells until
After ovulation, the egg lives only a few days, and if it is not fertilized, it disintegrates and is reabsorbed. Knowing this, predict the time of greatest possibility of pregnancy.
12 to 18 days
The uterus would be most prepared to receive the fertilized egg
between 16 and 21 days
During the menstrual cycle, high levels of LH cause the
follicle to release a mature egg
Increase in estrogen activity is due to
FSH stimulation of the ovary
Menstruation begins when the activity of
progesterone and estrogen are both declining
In animals meiosis differs between male and females
Cytokinesis is equal in males and produces 4 haploid sperm cells while Cytokinesis is unequal in females and produces 1 haploid egg and 3 haploid polar bodies which die
What happens during gamete formation?
a change from diploid to haploid
What structures are found in animal cells and not plant cells?
astral fibers, cleavage furrow, and centrioles
Meiosis is important because
It prevents the doubling of the number of chromosomes in each succeeding generation of sexually reproducing organisms AND it results in the production of cells with one of each pair of chromosomes
A cell with 8 chromosomes before mitosis will produce new cells that have
As a result of mitosis, each of the two new cells produced from the parent cell during cytokinesis
receives an exact copy of all the chromosomes present in the parent cell
What happens during asexual reproduction?
no change in chromosomal number
Which of the following secondary sex characteristics is caused by sex hormones?
development of facial hair in males, deepening of the voice in males, development of breasts in females
In mitosis, separation of sister chromatids occurs during
In the menstrual cycle, on what day does the flow stage begin?
Females stop releasing eggs and hormone secretions slow during
The somatic cells derived from a single-celled zygote divide by which process?
Separation of homologs occurs during
What is a malignant tumor?
a mass of abnormal cells which are spreading to other areas of the body
In meiosis, the chromosomes are replicated during
The muscle fibers of the scrotum contract and relax in order to
regulate the temperature of the testes
Menstruation does NOT occur if the
egg is fertilized
When does the human blastocyst implant in the wall of the uterus?
about a week after conception
Twins formed by the release and fertilization of two separate eggs are called
The most important difference between asexual and sexual reproduction is that sexual reproduction
introduces hereditary variation into the species
If an organisms body cells contain 6 chromosomes, its gametes will contain
the haploid number of chromosomes AND 3 chromosomes
during prophase I
A chromatid is attached to a spindle fiber by the
Write the phases of mitosis in proper sequence
prophase, metaphase, anaphase, telophase
Unlike mitosis, meiosis results in the formation of
The place in the male gonads where sperm is stored is the
Which process happens last?
In animals, somatic cells are produced by mitosis and _____ are produced by meiosis
Incomplete separation of the first two cells that are formed during cleavage and continued development results in
Complete separation of the first two cells that are formed during cleavage and continued development results in
A zygote is a
fertilized egg cell
The most effective method of birth control is
abstinence from intercourse
What change happens to chromosome number during fertilization
a change from haploid to diploid
The longest phase of the cell cycle is
Cancer is a disease in which some cells lose the ability to control their
rate of division
The greater chance that a break occurs between linked genes, the
greater the distance between the genes
increases the variety of offspring
are the chromosomes except the sex chromosomes
The 23rd pair of chromosomes that differ in males and females are called
Colorblindness is an X-lined recessive condition. What parental genotypes would result in children who are ALL normal vision daughters and ALL color blind sons?
X superscript B X superscript B and X superscript B Y
A man heterozygous for blood type A marries a woman heterozygous for blood type B. The chance that their first child will have type O blood is
Lobed ears are completely dominant to attached ear lobes in humans. What results are predicted in a cross between two people who are hybrid for this trait. The gene for the trait is located on one of the autosomes.
3 lobed: 1 attached