Write one function of each of the following five parts of the human eyeball: [1 × 5 = 5]
(a) Cornea
(b) Lens
(c) Choroid
(d) Vitreous humour
(e) Retina
OR
Mention three changes occurring during the Anaphase stage of mitosis in an animal cell. Write the names of any two structural parts of the eukaryotic chromosome. [ 3 + 2 = 5]
WBBSE
Class X
Life Science
01 (d) Nervous System
02 (a) Cell Division and Cell Cycle
05 Mark
2023
| Part | Function |
|---|---|
| Cornea | Refracts (bends) light entering the eye onto the lens. |
| Lens | Focuses light rays onto the retina for clear vision. |
| Choroid | Provides nutrients to the retina through its dense network of blood vessels. |
| Vitreous humour | Maintains the shape of the eyeball and supports the retina by filling the posterior cavity with a gel-like substance. |
| Retina | Converts light into electrical signals that are sent to the brain for visual processing. |
Or
Here are three changes occurring during the Anaphase stage of mitosis in an animal cell in very short points:
- Centromeres split, and sister chromatids separate.
- Mitotic spindle elongates, pulling sister chromatids to opposite poles.
- Nuclear envelope breaks down, allowing chromosomes to enter the cytoplasm.
Here are the names of two structural parts of the eukaryotic chromosome in very short points:
- Centromere: A specialized region of the chromosome that is involved in cell division.
- Chromatids: The two identical copies of a chromosome that are produced during DNA replication.
Related Questions
More WBBSE Moderate level questions
1/12
Q.
How is micropropagation performed? Which phenomena occur during telophase stage of mitosis in an animal...
A.
Micropropagation is rapid vegetative multiplication using tissue culture technique. It is performed...
Q.
Establish the interrelationship between gene, DNA and chromosome. What are the advantages of vegetative propagation?
A.
Chromosomes are the gene-bearing nucleoprotein filaments present within the nucleus, endowed with...
Q.
Describe the following features occurring during anaphase stage of animal cell division: (a) Division of...
A.
Anaphase ensures equal chromosome distribution. (a) Centromere divides longitudinally into two. (b)...
Q.
Write one function each of the following five parts of eyeball of human eye: (a)...
A.
Parts Functions (a) Cornea Refracts light rays entering the eye. (b) Lens...
Q.
Prepare a list of animals being endangered by poaching. Which environmental factors have the potentialities...
A.
Animals endangered due to poaching Poaching for skin, fur, horns, tusks, bones,...
Q.
Explain the relationship between the decline in the number of biodiversities with that of over-exploitation...
A.
Relationship: Over-exploitation refers to the excessive use of biological resources beyond their...
Q.
Show the major events of evolution with the help of a chart. What are the...
A.
The major events of evolution with the help of a chart Roles...
Q.
Write three inferences deduced from the observations as mentioned in Darwin’s theory of origin of...
A.
Observation Inference Prodigious reproduction There is a struggle for existence due to...
Q.
Black-smooth hair is produced in F₂ generation resulting from a cross between pure black-rough haired...
A.
Genetic counselling detects carrier status in parents for autosomal recessive diseases like...
Q.
Mention the dominant and recessive traits of two characters related with seed and one character...
A.
Here are two seed-related characters commonly used in Mendel’s experiments, showing their...
Q.
What is the role of cryopreservation in the conservation of biodiversities? What information may be...
A.
Cryopreservation is a method of ex-situ conservation in which living biological materials...
Q.
Prepare a list of diseases linked with pollution as observed by a doctor among her...
A.
Pollution causes respiratory, skin and other diseases via air, water toxins. A...