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

Question # 1

Differentiate between hydrophytes and mesophytes.

Ans 1: Hydrophytes: Hydrophytes are the plant which grow in aquatic environment (abundant water),they have large leave surface area and stomata are present on the upper side of leaves, they have high rate of transpiration. E.g., Water lilli, Wolfia, Pistia etc.
Ans 2: Mesophytes: These are the plants which grow on land where moderate water is available: they open their stomata during flooding and close stomata during drought.For Example: rose and mango.

Question # 2

Write down the mechanism of rapid movements of leaflets.

Ans 1: When Mimosa (Touch me not) leaf is touched, it rapidly loss its turgor pressure due to exosmosis which results in closing of leaves.K⁺ Ions also play role in this movement.

Question # 3

What is difference between oogenesis and spermetogensis in humans?

Ans 1: Oogenesis: In oogenesis, primary oocytes divide meiotically in to secondary oocytes and first polar body. Second meiotic division in the oocytes proceeds as far as metaphase but is not complete until the oocyte is fertilized by the sperm.
Ans 2: Spermatogenesis: during spermatogenesis primary spermatocytes under go meiotic division to form four secondary spermatocytes and spermatids which then differentiated into four mature sperms.

Question # 4

What is cretinism?

Ans 1: If congenitally thyroxin production is low,it may cause cretinism,where the individual fails to develop normally.These are small,have coarse scanty hairs,thick yellowish scaly skin and mentally retarded.

Question # 5

What is point mutation? Give two examples.

Ans 1: Point mutation are mutational changes that affects the message itself,producing alterations in the sequence of DNA nucleotides. If alteration involves mutations.For example sickle cell anemia and phenylketonuria.

Question # 6

Define turgor and osmotic pressure.

Ans 1: Turgor pressure is pressure exerted by the water on the walls of the vacuole while the osmotic pressure due to presence of solute in the water.It is also called solute potential.

Question # 7

Describe animal life in profundal zone

Ans 1: Decomposers and detritus feeders such as snails and certain insect larvae,bacteria,fungi and fishes inhibit it.

Question # 8

Give adaptation of marine fish for its survival in cold environment.

Ans 1: These fishes have a thick layer of insulting fat called blubber, which prevent excess heat loss from the body.

Question # 9

Differentiate between macro nutrients and micro nutrients.

Ans 1: Macro nutrients: Macrnutirents are those which required by the organism in large amount are called macronutrients like water,carbon,hydrogen,oxygen.
Ans 2: Micro nutrients: Micronutrients are those which required by the organisms in less quantity or in trace amount like sulphure,phosphorous,magnesium etc.

Question # 10

What is universality of genetic code?

Ans 1: It mean it is same for all the organisms.Because of the universality of codon the genes can be transferred from one organism to another and successfully transcribed and translated in their new host.

Question # 11

Differentiate between endangered and extinct species.

Ans 1: Endangered Species: Endangered species are those which are near to extinct.
Ans 2: Extinct Species: Extinct species are those which have been vanished from biosphere and even a single member is not present on the earth anywhere.

Question # 12

Differentiate between altitude and latitude.

Ans 1: Altitude: means height from sea level toward high mountains the altitude increases.The absolute height of a location usually measured from see level.
Ans 2: Latitude:means the distance from equator towards poles as we go away from equator towards poles latitude increases.

Question # 13

What is Pleiotropy? Give one example.

Ans 1: When a single gene affects two or more traits the phenomenon is called pleiotropy. E.g, genes that effect growth rate in human also influence both weight and height.

Question # 14

Name the hormones secreted by placenta.

Ans 1: Placental lactogen and progestron is secreted by the placenta.

Question # 15

Define apical and intercalary meristem.

Ans 1: Apical meristem: Apical meristem found at the tips of shoot and root. The cells of apical meristem has ability to divide throughout plant life. These are basically related to extension of plant body.
Ans 2: Intercalary meristem: These are the part of apical meristem which get separated from apex by permanent tissues. They are situated at the base of internode. They play important role in production of leaves and flowers.

Question # 16

What are nastic movement?

Ans 1: These are non directional movement of parts of plant in response to external stimuli.

Question # 17

Name only stages of prophase I of meiosis.

Ans 1: Following are the sub stages of prophase I of meiosis
Ans 2: i) Leptotene ii) zygotene iii) pachytene iv) diplotene v) diakinesis

Question # 18

What do you know about co-dominance?

Ans 1: Different alleles of a gene that are both expressed in a heterozygous condition is called co-dominance.

Question # 19

What do you understand by term trophic level?

Ans 1: The level in food chain at which organism feed is called trophic level.There are various trophic levels in the ecosystem e.g producers make first trophic level,herbivores occupy second trophic level and so on.

Question # 20

Give four important functions of mitosis.

Ans 1: Four functions of mitosis are
Ans 2: a) Asexual reproduction is due to mitosis
b) Healing of wounds and regeneration is also due to mitosis
c) It ensure equal or same number chromosomes in daughter cell
d) It transfer characters from parents to offspring without any change

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