Find the 12th Class Fsc Part 2 Short Questions Online Preparation Biology

Question # 1

Define terms menstruation and menopause.

Ans 1: Menstrual cycle:In human females the periodic reproductive cycle is completed in approximately 28 days and involves changes in the structure and function of the whole reproductive system. It is called menstrual cycle.
Ans 2: Menopause:The end or complete stop of menstrual cycle is called menopause

Question # 2

What is symbiosis?Give one example.

Ans 1: This is a beneficial association between two organism,which brings benefit to both the organisms.For example relation between algae and fungi to form lichens.Algae make food and also give it to fungi while fungi give protection to algae in return.

Question # 3

Define receptors.Give their types.

Ans 1: Receptors are the sensory organs which receive stimulus and transfer it to associative neurons via sensory neurons for further action e.g,eye,ear,nose,skin and tongue.

Question # 4

What is cerebrospinal fluid?Give its function.

Ans 1: Beneath the cranium,the brain and spinal cord are protected by triple layer of meninges.Between the layers of meninges the cerebrospinal fluid (CSF),similar in composition to blood plasma.
Ans 2: Its function is to bath the neurous of brain and spinal cord and it cushions against bumps and jolts.

Question # 5

What is meant by division of labour ?

Ans 1: Division of labour means a specific type of cells can perform a specific type of function.Like muscle cells contract and relax,glandular cells produce secretions, phloem can transport food.

Question # 6

Enlist any four types of learning behavior.

Ans 1: Four types of learning behavior are
Ans 2: Imprinting
Ans 3: Habituation
Ans 4: insight learning
Ans 5: Latent learning

Question # 7

What is renal failure?

Ans 1: When kidneys perform no more function and cannot filter blood to produce nitrogenous waste, this is called renal failure or uemia.

Question # 8

What is importance of kinetochore in the allignment of chromosomes during mitosis?

Ans 1: Spindle fibers attaches at kinetochore of chromosomes and they help to align chromosomes at the center of cell to from equatorial plate or metaphase plate.

Question # 9

Differentiate between parthenocarpy and apomixes.

Ans 1: Apomixes: In apomixes a diploid cell either from the nucellus or megaspore develops into a functional embryo in the absence of a male gamete.The rest of the ovule develops into seed and ovary into fruit.
Ans 2: Parthenocarpy: Formation of fruit without fertilization is called parthenocarpy. For example seedless grapes and banana.

Question # 10

Define phototactic movement and photonastic movement.

Ans 1: Phototactic Movement: is a types of tactic movement in which movement occur in response to light stimulus. Photonastic Movements:that in which photoperiod is critical in opening and closing of flowers.

Question # 11

What is diplohaplontic life cycle? Give its types.

Ans 1: In sexual reproduction,plants have diplohaplontic life cycle with alternating diploid sporophyte and haploid gametophyte generations. its type are isomorphic generations and heteromorphic generations.

Question # 12

Give four name of major terrestrial ecosystem in Pakistan..

Ans 1: Major terrestrial ecosystem of Pakistan are
Ans 2: i) Temperate deciduous forest
ii) Coniferous alpine and boreal forest
iii) Grassland ecosystem
iv) Desert ecosystem
v) Tundra ecosystem

Question # 13

What is the role of P₇₃₀phytochrome in flowering?

Ans 1: P₇₃₀induce flowering in long day plant while inhibit flowering in short day plants.

Question # 14

Give to role of cytoplasm in the development of an Ascidian.

Ans 1: For types of cytoplasm in Ascidian are
i) Clear cytoplasm produces larval epidermis
Ans 2: ii) Yellow cytoplasm produces muscle cell.
Ans 3: iii) Grey vegetal cytoplasm gives rise to gut
Ans 4: iv) Grey equitorial cytoplasm produce notochord and neural tube.

Question # 15

What is discoidal cleavage?

Ans 1: in bird's egg the process of cell division is confined to the small disc of potoplasm laying on the surface of yolk at the animal pole.This type of cleavage is called discoidal cleavage.

Question # 16

Differentiate maturation from differentiation.

Ans 1: Maturation:During maturation,the final size of a given type of a cell is attained.The cells which develop into pith,cortex and certain other tissues do not elongate further.
Ans 2: Differentiation:When the cell enlargement ceases,the process of differentiation starts.Wall of cells become pitted,thickening appear on the walls of xylem vessels etc.

Question # 17

What are endangered species?Give example.

Ans 1: An endangered species is in imminent danger of extinction throughout its range (where it lives)
Example: Cheetah, Tiger, Asian Lion, Indian rhino, cheer pheasant, crocodile and Gavial.

Question # 18

Name the synthetic auxin used as selective weed killer.

Ans 1: 2-4D (2,4 Dichlorophenoxy acetic acid)is selective weed killer.

Question # 19

Define reflex arc and give its components.

Ans 1: The path followed by the nerve impulse during the reflex action is called reflex arc.Its components are receptors,sensory neurons,inter neuron.motor neuron and effectors.

Question # 20

Name two sexually transmitted disease and their control.

Ans 1: Genital herpes and AIDS. These sexually transmitted diseases can be controlled by avoiding sexual contact with affected person and adopting the hygienic conditions and also by taking medical treatment.