12th Class Biology Chapter 4

“Explore the process of reproduction, its biological mechanisms, different types, and its vital role in ensuring the survival and continuity of species.”

Class 12 Biology Chapter 4 Notes

Menstruation usually lasts for: 3 – 7 days

In nature P 730 to P 660 conversion occurs in the: Dark

What will occur if a drug at the neuromuscular junction blocks the receptors sites on the post-synaptic membrane: Muscle paralysis

Which of the following is common in all neurons: A cell body which contains a nucleus

Luteinizing hormone induces: Ovulation

Information back from the control centre to the effectors as done by _____ nerve path way: Efferent

The union of meiotically produced specialized sex cells from each parents produce: Fertilized egg

Asexual reproduction requires only a single parental organism which gives rise to offspring by: Mitotic cell division

Germ cells in the ovary produce many: Oogonia

External genitalia of human male consist of a pair of testes which lie outside the body in the sac like: Scrotum

If fertilization does not occur the corpus luteum starts: Degenerating

Long-day plants will flower in short days if the interrupted period is: Long night

The groups of ribosomes present in the cell body of the neuron, which are associated with nough endoplasmic reticulum are called: Nissl’s gronules

From beginning of the 3rd month of pregnancy the human embryo is referred to as the: Foetus

Between the seminiferous tubules are interstitial cells which secrete: Testosterone

In human only one ovum is usually discharged from the ovary at one time this phenomenon is called: Ovulation

The electrical potencial of cell membrane of meuron when it is not transmission any signal is called: Resting membrane potencial

The number of human spinal nerves is: 62

In seminiferous tubules repeated division of the germinal epithelium produce: Spermatogonia

Effect of photoperiodism was first studied in 1920 by: Garner & Allard

Cocklebur (Xanthium),chrysanthemum, soyabean, tobacco, strawberry are examples of: Short day plants

If the two generations are vegetatively similar such alternation of generation is referred to as: Isomorphic

The mammalism forebrain is differetiated into the thalamus, imbic system and the: Cerebrum

Between the seminiferous tubules are interstitial cells which secrete: Testosterone

Tobacco plant produces flowers in: Winter

In nature P 730 to P 660 conversion occurs in the: Dark

Towards the end of pregnancy, the reduction in progesterone level, stimulates pituitary gland to produce: Oxytocin

What will occur if a drug at the neuromuscular junction blocks the receptors sites on the post-synaptic membrane: Muscle paralysis

The groups of ribosomes present in the cell body of the neuron, which are associated with nough endoplasmic reticulum are called: Nissl’s gronules

Germ cells in the ovary produce many: Oogonia

P660 is quiescent from, is converted to active p 730 by the absorption of: Red light

The hormones which promote boating of some roseate plants is known: Gibberellins

The mammalism forebrain is differetiated into the thalamus, imbic system and the: Cerebrum

Important : Review all previous years’ 12 class past papers for comprehensive practice and better exam preparation.

Leave a Comment