Question

L-shaped chromosomes are also called as
A. Acrocentric
B. Telocentric
C. Sub-metacentric
D. None of these

Answer 1

Hint: Chromosomes are thread-like structures located inside the nucleus of animal and plant cells.
Each chromosome is made of protein and a single molecule of deoxyribonucleic acid (DNA) Passed from parents to offspring. DNA contains the specific instructions that make each type of living creature unique.

Complete answer:
Chromosomes are tiny thread-like structures present in the nucleus of plants and animal cells.
Chromosomes contain DNA and some basic proteins known as histones, non-histone proteins and RNA also.
A single human cell has approx 2 metre long thread of DNA distributed among its forty-six chromosomes.
 Every chromosome essentially has a primary constriction or the centromere on the sides of which disc shaped kinetochores are present.
Based on the position of centromere, the chromosomes are classified into four different types:
1. Metacentric: In this type of chromosomes, centromeres are placed in the middle forming two equal arms of the chromosomes.
2. Sub-metacentric: In this type chromosome has centromere slightly away from the middle of the chromosome resulting in one short arm and one longer arm.
This imparts an “L” shaped appearance.

3. Acrocentric: In case of acrocentric, chromosomes the centromere is situated close to its end-forming one extremely short and one long arm.
They appear as rod-shaped or “I “shaped chromosomes.
4. Telocentric: In this chromosome has a terminal centromere.

So, the correct option is option C. Sub-metacentric.

Note: Cell cycle: It is a sequence of events by which a cell duplicates its genome, synthesizes the other constituents of the cell and divides into two daughter cells.
All these events are under genetic control.
The cell cycle is divided into two phases:
1. Interphase (95%)
2. M Phase (5%)
The interphase is further divided into three phases:
1. Gap 1
2. S phase
3. Gap 2
M phase is further divided into four different phases:
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase