Deck 2: Heredity Prenatal Development

Question 1

Some women are infertile due to ____________ , which can obstruct the fallopian tubes.

Answer 1

Ova are the cells that are released in the matured form from the female after the puberty due to the hormones estrogen and progesterone. An egg is released every month from the ovarian follicle mid way through the menstrual cycle. This egg if fuses with the sperm that overcome all the obstacles lead to conception.
Infertility means the lack of ability to produce offspring's or the disability to conceive due to many reasons. The main reason in males is low sperm count this may be due to genetic factors or the environmental poisons.
The most common factor for infertility in women is irregular ovulation. This may be due to hormonal imbalance or stress or improper nutrition. It may also due to infections in the fallopian tubules called the pelvic inflammatory disease or due to endometriosis.
Endometriosis is the problem of clogging of endometrium in the fallopian tubules that usually sheds down during the menstrual period. Even though it sheds off some of it remains and clog the fallopian tubules where fertilization takes place.
So the blank can be filled with
.

Question 2

Girls with which one of the following disorders are infertile, have poorly developed ovaries, and attain shorter than average height

A) Klinefelter syndrome
B) supermale syndrome
C) triple X syndrome
D) Turner syndrome

Answer 2

Humans have 46 chromosomes in that 23 are obtained from the mother and the 23 are obtained from the father. If there is any segregation problem or any mutation during the development of the zygote there will be mutations in these 23 pairs of chromosomes.
If there are any abnormalities it leads to problems in the baby. There may be sex-linked, genetic abnormalities or may be abnormalities in the autosomes.
Kleinfelter syndrome is a sex linked disease that is caused to males due to the extra X chromosome. Because of this extra X chromosome the males have more of female characters than the male characters and their genetic sex-chromosomal structure is XXY.
Hence the option (a) is not correct.
If there is an abnormality in the sex chromosomes the individual may suffer with maleness or femaleness. In maleness there will be an extra copy of the Y chromosome that expresses the male characters in higher levels and their genetic sex-chromosomal structure is XYY.
Hence the option (b) is not correct.
Triple X-syndrome is a sex linked disease caused in girls and has a genetic sex-chromosomal structure is XXX. They look to be normal but have poor memory and language skills. There are also some incidences of infertility.
Hence the option (c) is not correct.
Turners syndrome is another sex linked disease caused in girls and has a genetic sex-chromosomal structure is X means they have only one X-chromosome. They have normal genitals but the ovaries are poorly developed due to single X-chromosome and so are infertile. They are also shorter in length.
Hence the correct option is
.

Question 3

The outer layer of the blastocyst is the ____________.

Answer 3

Ova are the cells that are released in the matured form from the female after the puberty due to the hormones estrogen and progesterone. An egg is released every month from the ovarian follicle mid-way through the menstrual cycle. This egg if fuses with the sperm that overcome all the obstacles lead to conception.
After the conception the prenatal development is divided into three stages
1. The germinal stage
2. Embryonic stage
3. Fetal stage.
Germinal stage is of two months in the prenatal development. This phase starts from the conception and ends at the implantation. In the few days the zygote divides rapidly and forms like ball of cells called the blastocyst.
Blastocyst cells begin to divide and forms different structures. The outer part is the single layer of cells called the trophoblast but they differentiate into four membranes to protect and nourish the growing embryo.
So the blank can be filled with
.

Question 4

Which of the following is a dominant trait

A) straight hair
B) type 0 blood
C) farsightedness
D) lactose intolerance

Question 5

The ____________ is a pancake-shaped mass of tissue that permits the embryo and fetus to exchange nutrients and wastes with the mother.

Question 6

The period from conception to implantation is called the ____________ stage of prenatal development.

A) latency
B) germinal
C) fetal
D) embryonic

Question 7

____________ are the biological materials that regulate the development of traits.

Question 8

____________ is a life-threatening disease characterized by high blood pressure that may afflict women late in the second or early in the third trimester.

Question 9

Which of the following is accurate about the age of the parents and possible health risks for a child

A) Only the mother's age matters.
B) A female can be too young to bear a child without maternal health risks.
C) Only the father's age matters.
D) The age of both the mother and the father can matter.

Question 10

____________ is a powerful estrogen that was often prescribed during the 1940s and 1950s to help prevent miscarriage. Since then, it has been shown to cause cervical, vaginal, and testicular cancers in some offspring.

A) DES
B) progestin
C) vitamin A
D) thalidomide

Question 11

Dizygotic twins share ____________ % of their genes.

Question 12

Cigarette smoking by a pregnant woman is harmful to the fetus because it decreases the amount of ____________ available to the fetus.

Question 13

The arms and the legs are most vulnerable to teratogens

A) one to four weeks after conception.
B) four to eight weeks after conception.
C) eight to twelve weeks after conception.
D) twelve to sixteen weeks after conception.

Question 14

In ____________ , antibodies produced by the mother are transmitted to a fetus or newborn infant and cause brain damage or death.

A) preeclampsia
B) Rh incompatibility
C) spina bifida
D) FAS

Question 15

"Supermales" have __________ sex-chromosomal structure.

Question 16

Which of the following is not likely to be transmitted to the fetus through the placenta

A) HIV
B) aspirin
C) narcotics
D) alcohol

Question 17

_______ -cell anemia is most common among African Americans.

Question 18

About ____________ % of cases of infertility have un known causes.

A) 20
B) 40
C) 60
D) 80

Question 19

Sperm are apparently guided toward an egg cell (ovum) by changes in ____________ ions.

Question 20

Which of the following is a sex-linked disease

A) Tay-Sachs disease
B) Huntington's disease
C) hemophilia
D) cystic fibrosis