Answer:
Medulla.
By analyzing the DNA extracted from the hair follicle, the medullary index and the pattern of medulla in the hair samples obtained from a crime scene, an investigator can identify the owner.
Explanation:
The hair consists of follicle and shaft. The follicle is the part of the skin, where the hair grows and the hair shaft has three layers: an inner medulla, a cortex, and an outer cuticle.
The morphology (physical characteristics) of hair provides a broad detail on the racial background of an individual and an investigator can identify a group of people who share similar traits. But the hair without follicle cells attached to it, cannot be used to identify a specific individual. If the follicle of a hair is present, then it can lead to individual identification by DNA analysis. Also the medulla of animals is larger than that in the humans. By comparing the medullary index (the ratio of the diameter of the medulla to the diameter of the entire hair), it can be determined if the hair obtained from crime scene belongs to animals or humans. The macroscopic (length, color, and curliness) and microscopic characteristics ( pattern of the medulla, pigmentation of the cortex, and types of scales on the cuticle) of the hair samples are studied during a crime investigation. If the entire hair follicle (follicular tag) is present in the hair samples found at the crime scene, the blood and tissue attached to the follicle is extracted and analyzed using DNA profiling. DNA analysis of the hair follicle provides an identification with greater accuracy than the hair shaft.
<u>Answer:</u>
Theory is used to describe a fact that has always been observed true but could at some future time not be observed as true.
Option: (B)
<u>Explanation:</u>
- Hypothesis is a guess that is based upon the observation. Hypothesis is an idea that might occur in future but doesn’t fall in present theory.
- Generally hypothesis is not based upon facts and also they aren’t proved. Interpreting certain fact is theory.
- Theories are only the explanation of something but facts is observable.
- Theory is something like a concept or idea that is observed to be true at present may fail in near future.
- Law is absolute and true. Generally, they are represented by mathematical expression or equation.
- For example, Newton's law, Law of gravity, Law of thermodynamics.
Answer:
This is an example of biotechnology because it seeks to solve a societal problem using biological entities.
Spirilla are spiral shaped bacteria cells
Answer:
47 chromosomes
Explanation:
Meiosis is a kind of division that reduces the chromosome number of the daughter cells by half i.e. 2n - n. It occurs only in reproductive cells to produce sex cells or gametes. In humans, meiosis occurs to produce gametes (egg and sperm) that have 23 haploid chromosomes.
N.B: Somatic human cells have 46 chromosomes
According to this question, a meiotic error occurred during gamete formation, resulting in an egg that has 24 chromosomes. If that egg is fertilized by a normal sperm i.e. sperm with 23 chromosomes. A zygote that posseses (23 + 24) = 47 chromosomes will be produced.
