Answer:
Option A
Explanation:
In this case, there are two varieties of horses: Domestic horses that are raised and bred by humans and Wild horses that lives in the wild. The issue of varieties in coat colour of domestic horses can be explained as what occured by selective breeding, also known as artificial selection which is a technique by which humans develop new offsprings with desirable and suitable characteristics. These breeders select two parents that possess beneficial phenotypic traits to mate, producing offsprings with those desired traits such as strength and also for coat colour as stated.
Answer:
Oocyte: A cell in a ovary which may undergo meiotic division to form an ovum
Answer:
Two chromosomes that are similar but not identical are called homologous chromosomes. When the chromosomes are duplicated, two identical chromosomes are called sister chromatids.
Explanation:
Answer:
The Thymus is a unique gland which protects the body against autoimmunity when the immune system act against itself.Hence the Thymus plays a significant role the dual systems i.e.,the lymphatic system (body’s defensive mechanism) and the endocrine system
Explanation:
The Thymus is special gland located anteriorly to the chest directly behind the sternum and in between the lungs. Active until puberty and gradually shrinks to become fat after puberty.
Function: Prior to birth and during childhood thymus engage in producing and maturation of T-lymphocytes or T-cells a particular type of white blood cells which defence the body against infectious disease germs.Though the organ does not function throughout the life span but it plays a significant role protecting the body against autoimmunity refers to an immune system works against itself .Therefore the thymus plays a key role in lymphatic system and an endocrine system.
Secretion:Thymus secretes Thymosin a hormone it instigates the development of T-Cells ( disease resisting cells) Thymosin stimulates the development of T-Cells until a human attains its puberty.
At the age of 75 thymus becomes a fatty tissue.