Reproduction in Plant and Animals-4

Reproduction in Plants and Animals-4

Two Mark Questions Answers

Spectrum School

இரண்டு மதிப்பெண் கேள்வி பதில்கள்

In some plants, the flower bud modifies into globose bulb, which are called as bulbils, When these falls on the ground they grow into new plants.eg. Agave

Formation of a daughter individual from a small projection, the bud, arising on the parent body is called budding. eg. Yeast

The 4 Whorls of a flower are

a) Calyx - consisting of sepals

b) Corolla - consisting of petals

c) Androecium - consisting of Stamens

c) Gynoecium or pistil- consisting of carpels

The pollination with the help of wind is called anemophily

The anemophilous flowers produce enormous amount of pollengrains. The pollengrains are small, smooth dry and light in weight.

The stigmas are comparatively large, protruding and sometimes hairy to trap the pollengrains eg. Grasses and some cacti

i) It stimulates the ovary to develop into fruit

ii) It helps in development of new characters from two different individuals

The human sperm head is elongated and formed by the condensation of nucleus. The anterior portion has a cap like structure called acrosome.

It contains hyaluronidase an enzyme that helps the sperm to enter the ovum during fertilization

The menstrual cycle consists of 4 phases.

They are

1) Menstrual or destructive phase

2) Follicular or proliferative phase

3) Ovulatory phase

4) Luteal or secretory phase

The process of attachment of the blastocyst to the uterine wall (endometrium) is called implantation

The fertilized egg becomes implanted in about 6 to 7 days after fertilization

The developing embryo gets its nourishment through placenta inside the mother's body

The placenta is a disc shaped structure attached to the uterine wall and is a temporary association between the developing embryo and maternal tissues

It allows the exchange of food materials, diffusion of oxygen, excretion of nitrogenous wastes and elimination of carbondioxide

Oxytocine from the posterior pituitary stimulates the uterine contractions and provides force to expel the baby from the utereus, causing birth

1) The milk produced from the breast during the first 2 to 3 days after child birth is called colostrum

2) Milk production from alveoli of mammary glands is stimulated by prolactin secreted from the anterior pituitary

3) The ejection of milk is stimulated by posterior pituitary hormone oxytocin

The National Family Welfare Programme is comprehensive scheme, which includes

1) Maternal and child health care

2) Immunization of mother, infants and children

3) Nutritional supplement to pregnant women and children

4) Contraception with health education

The Intra Uterine Devices are

Contraceptive devices inserted into the uterus. There are two synthetic devices commonly used in India are Lippe's Loop and Copper -T

This reduces the sperm fertilizing capacity and prevents implantation

This also helps to give adequate time interval between pregnancies.

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