How do organisms reproduce Worksheet-6

How do organisms reproduce Worksheet-6

 

Subjective questions:

  1. Name the type of fission carried out by Amoeba.

 

  1. Write the expanded form of AIDS.

 

  1. What is vegetative propagation?

 

  1. List two functions performed by ovaries in a human female.

 

  1. Write the full form of IUCD.

 

  1. Write the full expansion of HIV.

 

  1. Name any two sexually transmitted diseases.

 

  1. What harm is caused if the testis in human males fail to descend into the scrotal sacs?

 

  1. List the general characteristics of the pollen grains of wind pollinated plants.

 

  1. What is double fertilisation?

 

  1. Why do testes in mammals descend into scrotum?

 

  1. How are males and females produced in honey-bee?

 

  1. Where does fertilisation take place in a human female?

 

  1. Name the following :

(i)     the tubes which carry spermatozoa out from the testes.

(ii)    the two phases covering the first half and second half of menstrual cycle respectively.

 

  1. Which technique would you use for propagating improved varieties of mango and rose?

 

  1. What is asexual reproduction?

 

  1. Mention one physiological advantage of grafting quality roses on wild rose stock.

 

  1. Name the male and female gametes in the animals.

 

  1. Name two chemical methods used by human female to prevent pregnancy.

 

  1. Mention the reproductive parts of a flower.

 

Answer:

 

  1. The expanded form of AIDS is Acquired Immuno Deficiency Syndrome.

 

  1. In vegetative propagation, new plants are obtained from the parts of old plants like stems, roots and leaves, without the help of any reproductive organ.

There are two ways of vegetative propagation:

(a) Natural Vegetative Propagation and

(b) Artificial Vegetative Propagation.

 

  1. The two functions performed by ovaries in a human female are

(i) It produces female gamete called ovum.

(ii) It secretes female sex hormones—estrogen and progesterone.

 

  1. IUCD—Intra Uterine Contraceptive Device.

 

  1. HIV—Human Immunodeficiency Virus.

 

  1. The two sexually transmitted diseases are

Gonorrhoea and Syphilis.

 

  1. Sterility is caused.

 

  1. (i) Pollen grains are small, smooth and dry.

(ii) They are produced in large quantities.

(iii) They may be winged as in Pinus.

 

  1. The fusion of one male gamete with egg to form embryo and other male gamete with two polar nuclei to form endosperm is called double fertilisation.

 

  1. The growth and maintenance of spermatogenic tissue and spermatogenesis require a cooler temperature than the body temperature. This is provided by the descent of testes into scrotum.

 

  1. In honey bees, males are produced parthenogenetically from unfertilised ova and females are produced from fertilised ova.

 

  1. Fallopian tube.

 

  1. (i) Vasa efferentia.

(ii) Proliferative phase and Secretory phase.

 

  1. Grafting.

 

  1. Asexual reproduction is the mode of reproduction in which new individuals are produced without the fusion of gametes.

 

  1. The rose stock is derived from a plant resistant to diseases and pests and is efficient in absorption of water and minerals.

 

  1. Male gamete is sr: rm and female gamete is ovum.

 

  1. The two chemical methods used by human female to prevent pregnancy are

(i) Use of oral contraceptive pills.

(ii) Use of Intra Uterine Contraceptive Devices (IUCDs).

 

  1. Stamen (male) and carpel (female).