71.

Which one of the following is not the function of placenta? It

• facilitates supply of oxygen and nutrients to embryo

• secretes oestrogen

• facilitates removal of carbon dioxide and waste material from embryo

• secretes oxytocin during parturition

One of the legal methods of birth control is

• abortion by taking an appropriate medicine

• by abstaining from coitus from day 10-17 of the menstrual cycle

• by having coitus at the time of day break

• by a premature ejaculation during coitus

Which of the following cannot be detected in a developing foetus by amniocentesis?

• Klinefelter's syndrome

• Sex of the foetus

• Down's syndrome

• Jaundice

Artificial insemination means

• transfer of sperms of a healthy donor to a test-tube containing ova

• artificial introduction of sperms ofa healthy donor into the vagina

• introduction of sperms of healthy donor directly into the ovary

Which Mendelian idea is depicted by a cross in which the F₁ generation resembles both the parents?

• Incomplete dominance

• Law of dominance

• Inheritance of one gene

• Codominance

The incorrect statement with regard to haemophilia is

• it is a sex-linked disease

• it is a recessive disease

• it is a dominant disease

• a single protein involved in the clotting of blood is affected

If both parents are carriers for thalassemia, which is an autosomal recessive disorder, what are the chances of pregnancy resulting in an affected child?

• No chance

• 50%

• 25%

• 100%

The diagram shows an important concept in the genetic implication of DNA. Fill in the blanks A to C

• A - transcription, B - replication, C - James Watson

• A - translation, B - transcription, C - Erevin Chargaff

• A - transcription, B - translation, C - Francis Crick

• A - translation, B - extension, C - Rosalind Franklin

Which enzyme/s will be produced in a cell in which there is a non-sense mutation in the lac Y gene?

• $\mathrm{\beta }$- galactosidase

• Lactose permease

• Transacetylase

• Lactose permease and transacetylase

According to Darwin, the organic evolution is due to

• intraspecific competition

• interspecific competition

• competition within closely related species

• reduced feeding efficiency in one species due to the presence of interfering species