CBSE 11TH BIOLOGY - Online Test
Q1. The number of chromosome and the amount of DNA are changed in
Answer : Option A
Explaination / Solution:
S phase marks the period during which DNA synthesis or replication takes place. During this time the amount of DNA per cell doubles. If the initial amount of DNA is denoted as 2C then it increases to 4C.and even in anaphase the chromosome numbers are changed.1
Q2. Homeostasis in the body is largely maintained by :
Answer : Option A
Explaination / Solution:
Homeostasis is the maintenance of constant body temperature. It is mainly maintained by excretion and osmoregulation, which is the function of kidney.
Q3. Sclerids belongs to
Answer : Option D
Explaination / Solution:
Scleroids belongs to sclerenchyma complex permanent tissue presentin hard parts of plants. They are generally hard and founds in rough fruits and stem.
Q4. The undifferentiated mass of parenchymatous cells are called
Answer : Option A
Explaination / Solution:
Plant callus is a growing mass of unorganized plant parenchyma cells. In living plants, callus cells are those cells that cover a plant wound.
Q5. The expansion of ICZN is
Answer : Option D
Explaination / Solution:
Animal taxonomists have evolved International Code of Zoological Nomenclature (ICZN). Hence, the correct option is International code of zoological nomenclature.
Q6. The correct organisation of skeletal muscle is
Answer : Option B
Explaination / Solution:
Each organised skeletal muscle in our body is made of a number of muscle bundles or fascicles held together by a common collagenous connective tissue layer called fascia. Each muscle bundle contains a number of muscle fibres. A characteristic feature of the muscle fibre is the presence of a large number of parallelly arranged filaments in the sarcoplasm called myofilaments or myofibrils. The portion of the myofibril between two successive ‘Z’ lines is considered as the functional unit of contraction and is called a sarcomere.
Q7. The movement of diffusion is
Answer : Option D
Explaination / Solution:
Movement by diffusionis passive, and may be from one part of the cell tothe other, or from cell to cell, or over short distances, say, from the intercellular spaces of the leaf to the outside.
Q8. Collagen is
Answer : Option C
Explaination / Solution:
In all connective tissues except blood, the cells secrete fibres of structural proteins called collagen or elastin.
Q9. In five kingdom of classification, prokaryotic, non-nucleated and unicellular organisms are included under
Answer : Option B
Explaination / Solution:
The fifth kingdom, Monera, contains all the single-celled organisms that do not possess a true nucleus. Members of the kingdom Monera are commonly referred to as bacteria.
Q10. The hormone secreted by pars intermedia of hypophysis is :
Answer : Option D
Explaination / Solution:
The hormone secreted by pars intemedia of hypophysis is melanocyte-stimulating hormones (MSH). MSH is a peptide hormone also knownas melanotropins.
